# The SF A2



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*THE SUREFIRE A2 – MORE THAN A COLLECTION OF NUMBERS*

If I had to choose only one light to keep—if I had to sell all of them except one—I would choose the SureFire A2. It’s that good.

And yet, many people regard A2 owners as fools parted from their money for buying such an expensive light that “only has 50 lumens” and “only runs for 50 minutes” and which is mainly an incandescent light (because everyone knows, or else should know, that incandescents are an inferior and dying breed of illumination tool!) Why then do I hold the A2 in such high regard? Allow me to answer that question over the course of this review.

_“Only 50 lumens”_

Let’s set the record straight: *the A2 is putting out something on the order of 75 to 80 lumens.* I know this for two reasons. First, a private lab tested several lights in an integrating sphere for Arc Flashlights, LLC, one of them being the E2e. They rated the E2e at 83 lumens on fresh batteries. I own both an E2e and an A2 and I cannot see any difference in total output between the A2 and the E2e running on fresh cells. Second, McGizmo tested the A2 in his integrating sphere as part of the CPF light-meter benchmarking project and arrived at 79 lumens.

That said, even supposing that the A2’s output really were only 50 lumens, the "only 50 lumens" remark would be a stupid comment for someone to make who has never seen the A2’s beam in person. A flashlight beam is more than a lux reading or a lumens total. The beam has a Correlated Color Temperature (CCT), or a “whiteness”; the beam has a profile or shape; it has a quality. A 500 lumen beam can be yellow and unfocused and full of artifacts, and a 50 lumen beam can be beautifully white and long-throwing and smooth. Only someone looking for a powerful spotlight could justifiably make this comment about the A2, sight unseen, but such a person would obviously not even be considering an A2, nor criticizing it for not being what it was never intended to be.

_“Only 50 minutes”_

The concept and measurement of runtime in a single level light is pretty straightforward: you turn it on and let it go and whenever you think it is too dim you stop the clock and write down a number. This can be when the output falls to 50 percent of the starting intensity, or can be to ultimate run-down-to-nothing dimness, but however exactly it is defined, it is straightforward.

Not so with a dual level light. Out in the field, in use, many tasks require only the low-level, or mostly the low-level with only occasional bursts of the high level. For example, I can walk in the woods and fields at night using mostly the low level from the A2, with only occasional bursts from the incandescent. I could be out walking and exploring all night with the A2, but the E2e, which some would consider to have a longer runtime, would certainly not last me more than 2 hours.

Now it is true that the A2 incandescent lamp can only be run for 50 minutes continuously on a set of fresh 123’s—I don’t deny that—but the point is that you wouldn't normally use the A2 that way, but even if you did, the LED’s would continue to run for many more hours after the incan turned off. In fact, (and this is one of the most important points I have to make in this whole review) *at the moment when the batteries no longer support the incandescent lamp, they still have about 25 percent of their energy left.* Yes, a full quarter of a tank left.

I determined this by taking the batteries out of my A2 the moment I tried to use the incandescent and it would not come on in regulation. I then installed them in my E2e, turned on, and measured the time until end of cycle dimming. I got a full 18 minutes of runtime, which is about a quarter of the total runtime of the E2e. I also took another set of batteries in the same condition and sent them to SilverFox, CPF’s own master of batteries, and had him run a test on them to determine how much capacity was left. At a 1 amp discharge rate, he found that a little over 80 percent of the capacity had been used when discharging to 1.0 volt, and a little over 70 percent when the test was continued to 0.5 volts. Thus, I believe that the 25 percent figure is an appropriate estimate. In any case, whichever figure you settle on, the point is that you have something left over when your high beam dies on you, by design. There is no need to worry over "what happened to the extra runtime"; no need to try to blame the regulator or the 10 ohm resistor in the tailcap or the holes in the reflector (although, certainly, some _light_ is lost there). The A2 was never designed to be a single level light with a fully regulated runtime that sucks the batteries dry before falling out of regulation. It is, start to finish, a _dual-level light_.

So, yes, if you’re only interested in the incandescent part of the A2, the 50 minute runtime is a downside—it means that you would never make use of the full capacity of the batteries. However if you use both levels of the light, as was intended, then you will find that these 50 minutes of incandescent runtime go significantly further than the 75 minutes of the E2e.

*THE SUREFIRE A2 – A SUPERLATIVE FLASHLIGHT*

OK, enough about those aspects of the A2 that are, in and of themselves, less than outstanding. Let’s move on to those aspects which ARE outstanding.

_The A2 incandescent beam_

The SureFire A2 is the only production flashlight with a regulated incandescent beam. Think about what that means for a second; think how we all might feel about LED lights if none of them was current regulated and they dimmed down over their runtime and degraded in tint. We might, as a whole, still prefer them to hardware store variety incandescents, but we would certainly not like them as much as we do now. That’s the situation that incandescents are currently in at this very moment. How many of the people who switched to LED’s because they were sick of “**** yellow incans” had only ever experienced alkaline direct-drive drug store cheapo lights, with bad batteries and lamps and a build-up of contact resistance? There is a huge difference between an under-powered and under-driven incandescent and a fully regulated over-driven incandescent. There is all the difference in the world.

When an incandescent is under-driven it is yellowy and relatively inefficient; but when it is driven hard, it is bright and white and relatively efficient. This quality appears in number form as the CCT, which stands for “correlated color temperature”. I had planned on talking about black bodies and color temperature and spectral peaks and so on, but I won’t. Suffice it to say that the higher the CCT, the “whiter” the beam. The best photographic lighting is 3200 to 3400 K. The average light bulb in your house is about 2700 K. Very few production flashlights are above 3000 K even at the start of run. Keep that in mind when I tell you that *the CCT of the A2 is 3300 K or slightly higher.* Besides being nice and white, a filament driven to this CCT is also very efficient, delivering about 30 lumens per watt.

The SureFire MN20 is also around this CCT at the start of run, and many hotwire mods are at this level or even higher (to wit the 1111 on 6 good NiMH cells, or the 1185 on 9 good NiMH cells) but the difference is that the A2 *stays at this CCT for as long as the batteries continue to support the incandescent*. The direct-drive lights that hit very high CCT’s at the beginning of the run, fall down to significantly lower CCT’s by the middle and end of the run.

Now, all of that being said, I should point out that a direct-drive incandescent light can still be a wonderful and effective tool. You do not _need_ to regulate an incandescent in order to have a good flashlight. I suspect that is why there are so very few regulated incandescents out there, production or otherwise.

In addition to being precisely voltage regulated, the A2 also has a soft-start feature which limits the current to the filament during the first 50 milliseconds or so after turn-on. This prevents the very high currents which would normally run through the cold filament and weaken, damage, or even blow it. This phenomenon is why almost all incandescent lamps die at turn-on, and this problem has been eliminated with the A2.

The high CCT, voltage regulation and soft-start are all very nice indeed, but they are made all the better by the other characteristics of the A2 beam. The A2 has a beautifully smooth beam that nonetheless throws exceptionally well for such a small light. Some people complain that the hot-spot is not round, but rather oval, but *this is an unavoidable characteristic of a transverse filament light which is focused for throw!* If the hotspot were made round, the throw would be reduced. It's that simple. Other people complain that the white wall beam profile has a ringed, unappealing corona. And, yes, it is true that the very outside of the beam has several brighter rings of light that detract from the white-wall aesthetic, but, only someone who is a very picky about white-wall beam profile would be overly bothered by these rings. In any kind of actual use, they are not noticeable and do not detract from the illumination effectiveness of the light in any way. Still, if looking at white wall flashlight beams is a favorite activity of yours, the E2e, L4 or L2 would be better choices.

On the other hand, if you value actual performance in the field, the A2 shines, out-throwing the E2e and L2 by significant margins, while still having a practically artifact-free beam. I have some beam shots of these three lights at two different distances which clearly illustrate the A2's superior throw, and they will appear below shortly, but first I need to say a few words about the method I used to capture these shots, because it is non-conventional. I first posted about this in my thread A new flashlight beam metrology and you can check out the link for more detail, but the method is simply to separate the flashlight and the camera by moving the camera closer to the object being illuminated. This allows a more even light to fall on the cameras field of view, making it easier to capture a good image, and it also shows the differences in throwing ability much more clearly and dramatically than the conventional method which places the camera and flashlight at very nearly the same place and pointing in the same direction. Two sets of pictures follow. The first set was taken with the flashlights on a tripod placed at 33 feet away from the tree being illuminated. The second set was taken with the tripod at 66 feet away. In both sets, the camera tripod was 11 feet away from the tree, at an angle to the beam-line so as to avoid shadows falling upon the tree. The camera was also angled slightly upwards from horizontal. The lights were held onto the flashlight tripod top by a rubber band, so the beam centers are not exactly the same from shot to shot, unfortunately. The variation is fairly small, though, and I think the shots are plenty consistent enough to be useable. So without further ado, here they are:

A2 at 33 feet:






L2 at 33 feet:





E2e at 33 feet:





Now for the shots at 66 feet, taken in the same order. Note that the A2 at 66 feet is pretty much as good as the E2e at 33!

A2 at 66 feet:





L2 at 66 feet:





E2e at 66 feet:





Also note that the color rendering is quite different, even between the E2e and the A2, although the greatest difference is between the E2e and L2. I took a daylight shot of the tree in order to show the "true" color of the object, but unfortunately I did not place the tripod in the same place. I wish I could have just left it there for the time required to have the beam shots and the day light shot be in EXACTLY the same location, but I didn't want to risk it. I cropped the photo below so that the tree trunk is more or less the same distance from the right edge of the photo:






In my opinion, the camera has exaggerated the differences somewhat. The L2 did not lack the reds and yellows quite as much as shown, and the E2e and A2 did not accentuate the reds and yellows as much as shown. Even so, this does partially illustrate the differences in color-rendering. I will let you decide for yourself which is better.

In addition, I took daylight shots from the point of view of the lights at both the 33 foot location and the 66 foot location in order to give you a feel for the throw distances involved. Here is the view from 33 feet:






And here is the view from 66 feet:





While I was out taking these shots, the coyotes were also out and about, sometimes sounding disturbingly close. Now, I was not afraid of being attacked by coyotes, but I can tell you that it sure was nice to have the A2 with me in order to tell if any were coming close to investigate. The L2 was completely useless for this task, and the E2e felt inadequate. Only the A2 had the throw that made me feel in command of the situation. The distances involved in the coyote scouting were probably three or four times the 66 foot distance I used in the beam shots above, but if I had tried to take shots with the lights so far away the pictures would have turned out too dim to be usable. So just take my word for it: at those distances the A2 not only ruled the E2e and L2 roost, but did so uncontested. The other two simply could not reach out that far.

Of course, there's more to a flashlight than throw! And the L2 and E2e are great lights and have their strengths, but just note that the A2 can throw much better than either the E2e or the L2. This concludes my discussion of why the A2 has such a superlative beam. I now move on to discuss the next superlative characteristic of the A2:

_The A2 switch and ergonomics_

Can I just wax poetical for a moment? Can I just say how simply *AWESOME* the A2 switch and hand-grip ergonomics are? From the first moment I had the A2 in my hand I knew that it was a perfect fit, a dream come true. And I mean that somewhat literally. I started out my SF experience with a D2, which is just a 6P with a pocket clip, and I could simply never get used to the grip. The feel was just wrong, and my hand kept slipping back towards the rear of the light with the pressure required to keep momentary mode activated on the LOTC. I took off the pocket clip to try to make things better. No luck. So I traded up to a C2-HA to take advantage of the grip ring. That, I thought, would solve things. The grip ring was key. But no, the C2 also simply never felt right, and was never comfortable to operate. So I sold it, and next tried the E2e. This was certainly better, but although it is acceptable, I was never fully satisfied with it: the light is too short for a good grip, and the LOTC spring tension is a bit too high. Nor did the clickie tail cap improve matters. I found the clickie uncomfortable to operate, mostly due, I think, to the insufficient distance between the thumb and first finger when gripping the light. So, I actually prefer the LOTC on the E2e.

Then came the A2. It was the grip and feel I had been wanting all along. The hand-grip to thumb-spacing is just right, and with the hand in position, the little finger rests just so near the bezel. It just feels _right_. It feels *good*. And the extra length over and above the E2e size is actually part of the secret, as well as the lower spring tension in the tail cap switch. To my taste, the tail cap spring has just the right amount of tension.

More importantly, the switch not only feels good, it *IS* good. This two stage switch gives you instant access to two levels of light from just one location. There is no need to click through some annoying LED ON--OFF--INCAN ON--OFF, etc. sequence. Nor is there a need to access another switch or selector ring in order to get the mode you desire. In addition, you can have both modes be momentary, or go to constant on LED, incan momentary, or constant on LED and incan, or, lockout incan with momentary LED, or lockout both incan and LED. I don't think many people realize how amazing an achievement this is. This level of engineering is rarely found in something so prosaic as a flashlight switch.

*THE SUREFIRE A2 – AN ENGINEERING MARVEL*

Which brings me to my next topic: this light really is an engineering marvel. Now, obviously, it's not an engineering marvel in the way that the space shuttle was an engineering marvel, or the Brooklyn Bridge, when they were unveiled. It is not pushing the state of the art. I say the A2 is an engineering marvel because it is one of the most, if not THE most technically sophisticated flashlights ever made. I say this for three main reasons: Willie Hunt's LVR regulator, the 2-stage LOTC, the MA02 A2 LA, and the quality of components, build, and machining. Let's take them one at a time:

_Willie Hunt's LVR_

Who the heck is Willie Hunt, anyway? you may be wondering. He is an engineer at SureFire, LLC, and he is the designer and creator of the LVR pulse width modulated regulators for use with incandescent flashlights. The name "LVR" actually stands for "lightbulb voltage regulator." You can check out his webpage at Willie Hunt's Lightbulb Voltage Regulators for more details and for some great information. The short of it is that the LVR3 series of regulators are micro-processor controlled PWM voltage regulators that are highly efficient, small, precise, and sophisticated.

So what’s going on with the LVR, anyway? Well, if you have a DMM, it is very easy, fun, and educational to try the following experiment. Remove the head of the A2 from the body of the light. Looking down at the top of the body, you will see a center contact, a ring outside of that, and the threaded top outside of that:






The ring is positive, directly from the top of the battery stack. The center is connected to the FET drain, and the FET source is connected directly to the body tube of the light, which is electrically and mechanically the same as the threaded top of the body of the light. The FET gate is controlled by the LVR circuitry. If any of that went over your head, "FET" stands for Field Effect Transistor. It is essentially a switch. You put something on one side of it (the drain), something on the other (the source), and then by applying voltages to the gate, you control whether or not there is a connection between the source and drain (a short-circuit=switch closed or "on"), or not (an open circuit=switch open of "off") or in the case of a linear circuit, something in between—a resistance, as opposed to a short or open circuit. The LVR is a switch-mode circuit, and so the FET is always either on or off or transitioning very quickly between those two states. (More on this in a moment).

So anyway, getting back to the experiment, the center is the regulated negative terminal for the incandescent lamp, the threaded top of the body is the negative from the bottom of the battery stack through the switch, and the ring in between is the positive from the top of the battery stack and is a direct connection. Thus you should note right away that there is no regulation circuitry between the batteries and the LED ring. When you activate the switch to the first position, there is a 10 ohm resistor from the battery stack negative to the LED ring negative, and a direct connection to the battery stack positive. Close the switch all the way, and the 10 ohm resistor is replaced by a short circuit, or in other words, a direct drive to the LED with no extra resistance. You may be able to prove this to yourself, by removing the lamp from the head, reinstalling the head without the lamp, and activating the switch. In some A2's, the LED ring contacts will mate with the middle ring and body of the light even without the lamp in place, and you can see that taking the 10 ohm resistor out of the circuit by depressing the switch all the way makes the LED's brighter than they are with just the first position activation. But I digress.

The point is that the center contact is controlled by the regulator. So, what happens when you turn down the switch to the position where the LED's would be on (if the head were installed), but the incan would be off? You might expect to find about 6 volts DC across the middle ring to body tube (LED's on), and 0 volts from middle ring to center contact (incan off). But you will find a suprise in store for you. There is also about 6 volts from the middle ring to the center contact. Why? Because the gate of the FET is pulled down, and the FET is "on." So why wouldn't the incan be ON in this position?

The LVR is on so long as it sees enough voltage across its inputs. The inputs are at the positive top of the battery stack, and at the negative ground return path of the body tube, which is on the other side of the switch from the battery stack negative. So if no current is flowing through the 10 ohm resistor, the LVR sees enough voltage to turn on. However, the instant current starts to flow to the LED’s, the 10 ohm resistor will drop enough voltage so that the LVR will turn off, because _it does not have enough input voltage to stay on_. It’s that simple. Or rather, I should really say, that it is that elegant.

And for those of you who have often wondered what is going on when your A2 appears to have three levels (LED, low incan, high incan) depending on how the switch is pushed or on the luck of the draw, here is what is going on: there is some extra resistance in the circuit. (Assuming you have fresh full batteries installed, of course--low batteries will exhibit this low incan mode even if all contacts are clean and everything is in working order) The extra resistance could be due to contact resistance in the LOTC floating contacts or in the battery stack or somewhere else. Or due to a broken spring contact. But somewhere there is extra resistance—just small enough so that the LVR sees enough voltage to allow it to turn on but too much to *keep* it on. So it turns on and starts to draw high current through the lamp, which causes a larger voltage drop across the switch and contact resistance, which lowers the LVR input voltage, which causes it to turn off; and the same thing happens over and over again. Sometimes you push hard enough, or the position of the floating LOTC contact on the end of the body tube is such that there is a small enough resistance to run the incan in regulation. But other times, there is too much resistance, and you put the LVR into an equivocating state of confusion about whether it should be on or off, resulting in a sort of in-between state, and thus the so-called "low-incan" level. If you remove the switch and simply short circuit the battery stack negative to the body tube, I bet you will find (in these situations) that it works fine. This indicates the need to clean the contacts inside the switch with a soft cotton pipe cleaner, and the butt end of the body of the light with a cloth or paper towel.

Let me talk about how the LVR actually regulates while it IS on and functioning properly with no extra contact resistance in the circuit. If PWM voltage regulation has you mystified, read on. It is really very simple in principle. First off, note that filaments will radiate light as long as they are hot enough, whether or not electric current is flowing through them at the time. The electric current only serves to make and keep them glowing hot. The incandescent lights in your home, for example, run directly from the 60 cycle AC line voltage. This means that 120 times a second, there is zero current flowing through the filament, and yet we don't notice this fickle drive source at all. This is simply because the time it takes the filament to cool down to, say, half its starting temperature, is quite long compared to 1/120th of a second. So as long as whatever crazy stuff is happening with the supply voltage and current happens fast enough, the eye and the filament won't notice, and will only see a sort of average of the applied power. I will simply be using the term "DC equivalent" to avoiding having to discuss RMS power and integrals and the like. The LVR switches the FET on and off rapidly in order to maintain a precise average DC equivalent voltage at the filament. In other words, it messes with the supply voltage in such a way that the filament sees the equivalent of whatever constant DC voltage set-point has been programmed into the uC of the LVR, and it does so rapidly enough that the eye sees no difference between that, and an actual DC voltage of the specified value. How does it do this?

Imagine that you are the operator of a mechanical flashlight switch, and imagine that you can turn that switch on and off more or less instantly, and that you are fast and alert enough to do this many, many times a second. So, you turn on and current starts to flow, then you turn off, and current stops. And you wait for a moment, then turn back on, and wait for a couple moments, then turn off, then turn on, and so on, and on, many, many times a second. And the amount of time you hold the on and off states depends on how hot and glowy and bright you see the filament being. When it just barely starts to be a bit dimmer than you like, you make your ON times a touch longer, and when it starts to be just a bit brighter than you like, you make your OFF times a touch longer. At some point, as the battery voltage drops, you reach a state where your ON times are very, very long, and your OFF times are very, very short, and you are simply passing the battery voltage directly to the lamp. After that, the lamp will of course start to dim despite your best efforts at regulation. Or perhaps you will have had instructions to turn off once that state has been reached.

THAT, in essence, is pulse width modulated regulation. And because the switch drops no power when on (because it is a short circuit and thus has almost no resistance), and drops no power when off (because it is an open circuit and no current is flowing), and switches so very fast between these states, the regulator is very efficient. There is pretty much nowhere to drop any power! In point of fact, the LVR3's are better than 98 percent efficient, and will handle up to 10 amps of current.

_The 2 stage LOTC_

I have mentioned this a number of times before, but I want to talk more about how much machining and engineering design must have gone into this switch. For those of you who are familiar with all the trouble Arc Flashlight had with the Arc4 switch, or with the trouble that the first FireFly’s had with the o-ring engaging before threads, despite the simplicity of the switch (a simple twisty), you may begin to have an understanding of what the SureFire engineering team must have faced when trying to implement this two stage switching concept, and bring it into reality as a perfected, functional, reliable switch. I'm no machinist, and I’m no expert on thread types and CNC machines and lathes, but I can tell you that the threads on the A2 tailcap are a special type of thread. According to a post of McGizmo’s, they are “Acme lead screw type thread” and because of this “Longitudinal displacement per revolution (pitch) is increased in a very robust and dependable fashion with this choice of thread.” In other words, there is very little play in the mating of the threads.

But don’t take my word for it! Remove the LOTC from your A2 and look at the threads on the end of the body from the side. Check out their profile. Now compare them to a regular old bolt, or even the threads on your Arc LS or mini Mag or Q3. See any difference? You should notice that the A2 threads are just about rectangular in profile. Most threads are triangular, or are saw-toothed shape. And this is only the tip of the iceberg. The simple truth of the matter is that this 2 stage switch all by itself is mechanically more sophisticated and more expensive to produce than most flashlights in their entirety.

Let’s take a look at the internals of an A2 switch. There are seven major components: The rubber cover, the threaded plastic retaining ring which holds it down, the metal body, top and bottom injection molded pieces, between which are sandwiched a circuit board with three upwards protruding tabs or fingers, and the spring, which is riveted onto the bottom injection molded piece. The top injection molded piece is captive inside the top cylindrical housing of the metal body. It travels in one direction as far as the underside of the cap glued on top of its shaft, and as far in the other direction as the shoulder of the piece itself. In order to remove it from the metal switch body, the cap must be broken off from the shaft, and then the two injection molded pieces and circuit board and spring will all come out the front of the metal switch body with a little persuasion. Here is a picture of the top of the switch with the retaining ring and rubber cover removed:






Note that while it may look as if the center cylinder could be unscrewed from the main switch body, it is in fact all one solid piece, and what you are seeing is the glue/sealant which was underneath the edge of the rubber cover.

And here are the internals of the switch after the cap was removed and the internals were pushed out of the switch body:






Those three metal fingers attached to the circuit board between the two black plastic pieces are electrically connected to the center spring via a 10 ohm resistance. When the switch internals move forward enough for these to touch the end of the flashlight body, then the LED circuit is completed through the 10 ohm resistance, but the LVR does not see enough voltage to turn on, and so the incandescent stays off.

However, when the internals are pushed forward even farther, the ends of the fingers bend down and touch the coppery colored pads directly underneath their ends. These contacts are short circuited to the spring, and thus cause the 10 ohm resistor to be taken OUT of the circuit path. Thus the LVR will see enough voltage to turn on and power the incandescent (assuming the batteries are fresh enough). Here is a close-up of one of the metal fingers and short-circuiting pad contact underneath it:






The internals can be pushed forward by simply moving along with the switch body as it is twisted in, or they can be pushed forward by a force applied to the cap on the end of the shaft on the top injection molded plastic piece. And alternately, if the switch body is turned back far enough, then the internals can be too far away for the tabs to be bent until they touch the contacts underneath them no matter how hard the rubber cover is pushed (incan only locked out, LED momentary), or even too far away for the tabs to make contact with the body at all (both LED and incan locked out).

I hope that it is obvious why I say that this switch all by itself contains more design, engineering, and machining than most flashlights in their entirety. If it’s not obvious, here’s why: two injection molded plastic pieces, one circuit board, one molded rubber cover, and a fairly THIN complex metal body that needed to be machined from both ends. The thinner walls and smaller dimensions of this piece mean tighter tolerances which means more precise and expensive machining. More than that, though, is all the design that had to go into making this switch work reliably and repeatably. As a finished, _fait accompli_ it is easy to dismiss it as easily done, but I am quite sure that it was not at all easy to design, build, and test, and that it probably involved many hours of work from high-paid engineers and technicians.

In short, the A2 switch is a marvel.

_The MA02 A2 lamp assembly_

We are all a bit jaded about SureFire lamp assemblies; we take them for granted, or even consider them to be over-priced, over-designed units that are just another way for SureFire to extract more money from its poor, ill-used customers.

Not so.

These lamp assemblies are, in fact, *ASSEMBLIES*! As one of the few people on CPF who can pot his own lamps, let me assure you that the SF LA’s are something special. Take a look at the MA02, for example:






First, notice that the bare lamp itself is potted into the plastic housing. Next, notice that there is an outer metal ring and a center rounded contact. The lamp filament is perfectly centered relative to the axis of the plastic housing, and is at exactly the right height above the shoulder of the housing so that when the LA is installed in the head of the A2, the filament is properly focused. There is simply no easy way to accomplish these two, simultaneous alignments, and if you think there is, then I challenge you to do it. And tell me how so I can steal your method for myself. :devil: Seriously, though, a lot has gone into making the MA02, above and beyond the lamp itself, which is a very nice high pressure xenon lamp with enough halogen added to it to slow the rate of tungsten deposition on the glass, but not enough that the pressure would need to be lowered in order to prevent corrosion of the filament and support wires.

So before you take the MA02 for granted, or even dismiss it, take a careful look at it and start thinking about how you could do it cheaper or better!

_Quality of build, components, and machining_

The A2 is as well made as flashlights come these days. The aluminum is of the highest grade, with hard anodizing and chem coating. The lens is pyrex, the reflector is machined aluminum with vacuum aluminizing and undercoating. Everything is o-ring sealed. And so on. I could go on, but let me just show a couple pictures. Here is a cutaway of an A2 which I stole from one of Size15s posts:






And here is a nice picture of the machining that went into the head and reflector, which I stole from one of McGizmo’s posts:






Go to a machine shop and try to get quotes for something like this.

And anyone can see all the detailing that went into the outside of the body, especially at the top where the head threads on, and where the pocket clip is attached.

But there is so much more that is unseen or unknown. Some of it I know about and have tried to convey, but almost certainly there is a lot of stuff that I don’t know and thus couldn’t mention. One thing I can tell you by way of example is that not only is the regulator in the A2 a highly efficient and sophisticated piece of electronics, it is also covered in a conformal coating which is water proof. According to a post I read here on CPF, PK went to some trouble to find the right coating for the LVR. And the same care and attention went into the rubber for the switch covering and into the choice of spring and into the plating on the contact points. And then there is the LED ring with surface mount resistors.

And on and on.

Quite simply, to my mind, it is amazing that the A2 was ever envisioned, designed, developed, and marketed. I am even tempted to say that the A2 really shouldn’t exist in this cut throat commercial and cynical world. But it does, and I for one give thanks for this small miracle of a flashlight.

This concludes the first part of my discussion of the SF A2. In later posts I will provide a lot of links to important past CPF threads on the A2, and more technical details, such as the DC-equivalent voltage set-point of the LVR and power being applied to the lamp, and the current going to the LED ring, and various non-destructive tests that can be done on the A2 for fun and enlightenment. And also some discussions of other technical aspects of the A2. But for now, I really just wanted to get this much posted, as I could have kept adding to this post and re-writing and revising it and so on until I found that it was late 2010 before I ever finished. It’s not perfect and it’s not all that polished, but some may find this post worthwhile. So there it is, and I hope you all enjoyed it.


----------



## edison

This is the longest post I've ever seen. I'm speechless.


----------



## TENMMIKE

that was the best " i love my light " ever , however i ll keep my GLADIUS


----------



## falconz

*applause*
Took me all of 20 mins to read this post....
And almost made me go out there and buy a A2 for EDC!!

if I got the $$$!


----------



## glock_nor_cal

That was awesome. I just want to say thank you. Surefire should say it to you because I'm probably going to buy one now.


----------



## atm

Fantastic, thank you Jim!

This really does show the A2 in a whole new light (sorry), and indeed the sort of work that goes into high end lights such as those made by SF. 

Part of what appeals to me, and I imagine most flashaholics, is the level of technology and engineering required to make a really good light. Never before have I seen these elements described so well.

Andrew


----------



## kukula

Thank you so much for your post js. I am sure that now, alot more people will see the "light", and seriously consider the A2. I dare say that of all my SFs, the A2 is my favorite. As a matter of fact, I own two A2s. One for me and one for my wife. Its that good, and its the only light I truly trust and personally chose for my wife to EDC :rock:


----------



## Grubbster

Amen brother Jim! :bow: :rock:


----------



## Planterz

Except for a big honker like a Magcharger, Ultrastinger, or Tigerlight (to keep in the car I don't have), the A2 is the only incandescent I'd ever consider owning, mostly because it's regulated. I'd probably own one already, if I weren't spending all my money on LEDs.

Great write-up!


----------



## leukos

This thread should be entitled, "Ode to the A2" or "The A2 Panegyric" 
Nice work, Jim! :goodjob:


----------



## this_is_nascar

Awesome post Jim. As you may or may not remember, when the A2 first came out, I couldn't stand the light, the cost, the hype. I had gone back and forth.......... I don't like it, I do like it, It's just OK, etc. That was a couple years ago and throughout all my selling and trading, I've always made sure to have at least (1) A2 in my possession. It truely is a one-of-a-kind light and it my main light when the wife and I do night-time Geocaching, hikes or walks along the trail.


----------



## nightshade

Jim, totally excellent post! :rock:


----------



## IonFire

Nice write up friend.

I think i can apreciate the A2 in a different light now hehe.


Thanks for your work.


IF


----------



## ACMarina

A2 was my first quality light, and this post simply makes my light feel that much better  Bravo.


----------



## bwaites

WOW!!!!

Beautifully done! 

Now I know why I like my A2's so much!!

Bill


----------



## Size15's

Wow! :bow:

I don't have much time online at the moment and I am so glad the one post on CPF I did read was this one.

I've always had a thing for the A2 as some of you may know.

Thank you Jim!

Al


----------



## greenLED

That is an excellent review, js!  (now I want one ) Thanks for sharing all the technical info on how the light works. I'll have to read this again a couple of times. 

Incidentally, the new BD hybrid (incan/LED) headlamps are also regulated (by Willie's circuits too, IIRC). Not your "tube flashlight", but the regulation is there.


----------



## cslinger

Ummm yeah, what he said. Love my A2s and if I could only have one it would likely be an A2.

Chris


----------



## Lightedge

I ALMOST feel bad that I just spent a big chunk of my light budget on a Ti CR2 Ion and a Glaius. Note that I said 'ALMOST'. I'm not unhappy with my decision at all but I think I now have another "need".

Great post!


----------



## NeonLights

Saved to my hard drive for posterity's sake. Excellent review.

I've had my SF A2 for several years, it is one of the earlier versions with a S/N below 800. I've bought and sold many SF lights over the years, but the A2 is one I always plan to hang onto. The A2 and my early L1 (S/N below 200) are two of my favorite lights and complement each other very well. In fact, the SF A2, SF L1, ARC AAA and my Tigerlight FBOP handle 99% of any situations I could ever need a flashlight for, with the A2 being able to cover about 90% of those situations by itself. It has to be the most versatile light I own, by far.

-Keith


----------



## carrot

Mmm... thanks for making me love my A2 even more. As I said in my own review of the A2, the ad for the light in PopSci was what got me to where I am now (CPF!) for better or for worse.
... I think I need to buy another. Or two.


----------



## nc987

Call me an oddball but the A2 has absolutely no appeal to me. I am not trying to knock it I just dont see what it can do that my U2 cant do. Ive used every A2 color combination out there and I have yet to be impressed. The main beam is nothing to scream about. If I need a red light or something i just use a filter. Not to mention the Kroma is coming out soon and will be able to do everything the A2 can do but better with different levels of output on all lighting sources. 

Also, just curious, how long as the A2 been out?


----------



## mountaineer

:wow: Now that was good . The A2 is next on my "light to buy" list . 

Great job . Im going to print this post out for refrence . 

Kenny


----------



## UVvis

TENMMIKE said:


> that was the best " i love my light " ever , however i ll keep my GLADIUS



I have to agree. I really do like the A2, but I like my Gladius more for its functions. The A2 is nearly the perfect incandescent light, if it were shorter I would like it more.

Great post up there.


----------



## dangerman

It was great to read your post and see I have company as a fan of the A2.

The A2 made me a flashaholic. I found it mentioned on the net and eventually ended up at the CPF. The A2 then went on to became my first "serious" flashlight purchase. I loved what I saw about it but couldn't rationally justify the cost with my needs. But I still wanted one. I agonised for weeks before buying and it is still my most expensive light, but I have no regrets. 

The low light setting is a perfect example of less being more. At first I was a little disappointed with the tint and brightness. But long term use has made me realise how it is nearly perfect for many tasks which do not require bright light. Such a very useful level of light that lets me see whats going on but keep some night vision (and not wake the baby)! 

The High setting still brings a smile to my face. I still remember the first time I nervously tried it out. I was just so delighted. Great for seeing out a fair way and impressing non flashlight people. I just try not to mention the cost, since they never get that part. The wife still doesn't fully understand the whole flashlight thing but she learned to accept it. 

Lastly I also love the feel and look of the light. It really exudes that feeling of quality , of being well built.


----------



## rscanady

BUMP for an excellent post! Thanks


P.S. I have 2!


----------



## bwaites

What the A2 does that no LED so far has done is color rendition, as Jim mentions above. 

I like my U2, I like my U binned Aleph3 with two stage, but the A2 is the light that goes EVERYWHERE with me.

Bill


----------



## Kiessling

js ... :thumbsup:

... and dito. A2 is a marvel, and even I as a LED guy can say this with all of my heart!

AND ... it can change beam profile form low flood to high spot ..... which is really useful, too.

bernie


----------



## hector

Brilliant!

Now I have no choice but to get one. I have the L2 and e2e, and couldn't agree more with your descriptions of them. I have a T3 which throws well, but you don't need that much light all the time. Sure you could carry two lights, but it's not as much fun to have it all in one package.

Thanks again.


----------



## onlinewarlord

Now I'm starting to think that I "need" a second A2.... 

Well there are 5 different versions right?


----------



## cobra-ak

yeah I am going to get another A2


----------



## wquiles

Fantastic post Jim :goodjob: 

Not only I agree with your statements about the A2, but it has been my EDC for work and even while travel for the last several months, and one of my main lights for walking at night due to the excellent color rendition - what a light!

Will


----------



## js

Thanks everyone for your kind words and appreciative posts! This A2 thread of mine was a LONG time in the making, and your responses make it all worth while. Thank you again.


----------



## Bob_G

For me the most interesting thing about the A2 is simple - the incan beam. I'm reasonably certain that it's just a by-product of the basic design, but the spot is actually a useful size- almost ideal for near to mid distance, where most people need light most of the time. I'm sure if they wanted to they could have found a way to have some silly little spot, but they didn't, to their eternal credit as far as I'm concerned.

Because of your post I dug it out of the car (side note: it seems like the perfect emergency car light to me, so I never get to use it!) and took it for my nightly dog walk, along with an Aleph 2 (DB700 U-bin) and they were very similar in range and spot size. I live in the country, it was a dark night, and we take long walks, so a good environment for comparing two similar but at the same time very different lights. If you wanted to get serious and make a scientific study of the performance of the two lights, you could spend as much time and effort as you wanted and still come to a :shrug: Two things stand out though - outdoors, our eyes like the light produced by something burning hot, and the A2 low is freakishly perfect for walking around in the dark in familiar areas. 

It's also the only SF I own (had an L2 but sold it.)

Oh, nice job


----------



## ths11

js,

I've been eagerly waiting for this review ever since you mentioned you would do one on the A2...and what can I say...you never disappoint (except when you cancelled the 2nd run of M6-Rs that I was waiting day and night for :mecry: ). 

On a side note; I got the black (SupremeCo) version since it was a bit cheaper, and I liked the look of the black. It has a 4-sided body. I’m not sure but I think I heard somewhere that the newer A2s have a round body, but all the pictures I can find seem to have the same old 4-sided body. I am thinking that a round body might fit better in my hand (as well as being an excuse to get another one). Could someone verify this?

Thanks for the fantastic review! :bow: :goodjob:

Surefire might be getting a suprise barrage of A2 orders soon. :laughing:


----------



## js

ths11,

You're most welcome, and I'm sorry I cancelled the 2nd run, but there was just nothing else for it. I'm still only just past halfway on the 1st run!

Here is a picture of an E2e with Balrog BE2 body (leftmost), a black A2 just like you have, a HA-NAT three-rounded sides A2, and a HA-NAT L2 with square sided body:







I actually prefer the square-sided body to the three-rounded sides body, but they are both comfortable and pleasing. I'd certainly be happy with either one. I have two A2's--the black one shown in the pic, and a HA-NAT with square-sided body (not shown) whose tail cap was sacrificed for this thread--although the rubber was all soft and squashed out from lots and lots of use, so it was time for a new tail cap anyway. The three-rounded sides A2 shown in the picture above is actually SilverFox's yellow-green LED A2 on loan to me so I could check out what a yellow-green LED A2 was like.

Anyway, does any of that help? What was your question again? :thinking:


----------



## makar

great post js! :thumbsup: i feel exactly the same about the a2.
marc


----------



## liteboy

wow, couldn't read the entire post but it made me take out my A2 and caress it for a lil bit...


----------



## The Porcupine

Outstanding post, Jim! Thanks for taking the time!
If I didn't already have an A2 (a gift from my best friend, no less!) I would have to buy one now!


----------



## rabbit

WOW! I bought my A2 because of Size15s's recommendation on here, been my EDC since and you are so right! 

Thanks for sharing!


----------



## lightplay22

Great post!!!!!!!!!!!! Now I 'm even more sure that my hard earned money was well spent on my A2 and the one I bought my wife. If only one light to choose, for me it would be A2, its just so good! Thanks for that post; It should be somehow posted on surefires website. Great information!


----------



## Topper

Jim, you inspired me to find mine. It has been AWOL for a month;maybe two. I found it (right where I left it) blew the dust off and still good to go. Thanks for you super review on the A2.
Topper


----------



## SilverFox

Hello Jim,

Very nice review, but it is actually more than "just a review." The technical aspect of this light is amazing and it is great to hear it explained so clearly.

I put off getting an A2 for a long time. When I put together the Light Meter Benchmarking testing, one of the lights we are checking is an A2, I decided that it was time to get one. I ended up with the yellow green LED's and find this combination extremely useful. After reading your technical description, I appreciate this light more than ever.

Tom


----------



## PoliceScannerMan

WOW! I'll read the second half in a little bit. Great post so far, wheres my Visine....


----------



## yaesumofo

What more can be said? The A2 Rocks.I love mine.
Yaesumofo


----------



## 270winchester

so uh, Jim, you like the A2 eh?


----------



## greenLED

Man, I just re-read this, and I'm one step closer to wanting one. I'm not sure if my wallet thanks you, js (I sure do! )


----------



## Cornkid

I am teetering at the edge of buying this beautiful flashlight.

-tom


----------



## rabbit

Mine is with white LED, is it true that the 'yellow green' led is brighter? Thinking of getting another one after this review :rock: but with different colour led.....


----------



## cy

great post!!!

A2 is one of my keepers


----------



## SilverFox

Hello Rabbit,

I measured the A2 with white LED's at around 40 lux (at 1 meter) on the LED's, my yellow green A2 comes in at around 8 lux. The yellow green is quite a bit dimmer, however for dark adapted eyes, it is great.

Tom


----------



## GadgetTravel

Wow, fantastic post. Thanks.

I usually have my HDS U60 with me in my pocket at all times. I often also have my A2. When I travel my A2 is always in my backpack and on the nightstand in my hotel room if in case I need a light in the middle of the night. I lost my first one, a white LED model, and got a YG LED model. I might have to go and get another white LED this week 

Thanks again for the post, and I agree completely. Nothing beats a good, regulated incan. Coupling that with the LED is just a fantastic light.


----------



## ths11

Thanks for the pic js.

So the newer A2s do have a round body. Now I definitely will have to get one. I think an A2-HA-RD would be good for indoor use, or maybe an A2-HA-YG...or...

I have MJLEDs in my black A2, mainly because the original ones were a bit too blue for my taste, and I pulled them forward a bit for even more flood. I use R123s and the MJLEDs seem to be doing fine.

One suggestion: there have been a number of threads about the A2, but since this is without doubt THE definitive A2 thread; why not add links to relevant threads in the first post (like the USL index thread)? Searching for them is a real pain.

Then we could point here whenever someone asks for info on the A2.

A few to start off:

Dummy reference guide to SF A2 modding with MJ led (or 35k 5mm) leds
warning about overdriven LED's in the A2
Rechargeable A2?
A2---Help with Removing Lanyard Ring
A2 tune up thread
Problem with Surefire A2?
Surefire A2 dimming LED???


----------



## js

ths11,

I am planning on providing some links, especially the older threads I found on the A2--they're really neat.

But, this isn't the definitive thread on the A2, I don't think. It covers ground that maybe wasn't very well covered before, but it leaves a LOT of ground uncovered. I mean, I didn't talk about LED color choices or make comparisons to lots of other lights, or tell how to do regular maintenance and upkeep, or mods, or troubleshooting, etc., etc. A thread would have to be about three or four times the length of this one to be the definitive thread.

I only wanted to make a contribution to the collection of threads about this fine light. That's all.

What I really want to do next, in addition to the page of links, is post a picture of the o-scope readout of the LVR output to the lamp, and give the DC-equivalent voltage set-point and RMS power going to the lamp. Plus the LED-ring current draw (for all three, which is just over 100 mA on primary 123's). And all the neat tests a person can do to his A2 to non-destructively figure out (or convine himself of) what's going on. And discussion of whether or not there is a liner (there is), and what it's for (I think for structural/machining purpose: to hold up the LVR but still allow the body to be created by drilling through from one end) and so on.

But for now I'm going to let this rest. I may post the links sometime in the next week or so, but not the other stuff yet.

Although, I will just mention to people that you can not simply put a DMM in series, in place of the tail cap, and get a valid measurement of the current going to the lamp.

As far as I know, no one here on CPF has really accurately, scientifically calculated these figures for the LVR3L and MA02. Some good guesses are floating around but they have not been carefully and accurately confirmed.

I believe I have those numbers now, but I want to be sure before I post them.


----------



## leukos

Sounds like the A2 is getting some serious scholarship!


----------



## cqbdude

What a great post....:rock: 

Thank You for a great write up of the A2...
I have the A2 also ...but unfortunately its been getting neglected..
But after reading your post...I think its coming back out...


----------



## carrot

While searching for more stories to add to my own thread, came across this one about the A2:
A2 an Engineering Marvel? + CPF then & now
If I come across any more, I'll put them in this post for you, js.


----------



## boostmiser

Good write up. I love my A2 too and it's pretty much the perfect light. I bought the black HAIII. As much as I love it, I find myself using the Strion more because it's rechargeable. So, with that said, *what is the best rechargable setup for the A2?*


----------



## glock_nor_cal

I cant decide which LED color to get!!!


----------



## GadgetTravel

glock_nor_cal said:


> I cant decide which LED color to get!!!



Depends on how you plan to use it. For most uses though, after having a white (which I lost) and a yellow-green, I think the white is the best all around. Im planning on replacing my white one. I just cant decide whether to get another A2, a Chameleon or a McLux PD first.....


----------



## Phaserburn

js: Simply, En Fuego!!

Sooo many people miss the frickin' point when it comes to hybrids, especially the superlative A2. It's NOT _just_ the multiple light levels, ala U2. It's also NOT _just_ the different color reditioning. It's the different beam pattern! Using the U2 or just about ANY multiple level luxeon flashlight will reveal that you get the same beam pattern, just less lumens. Thus, you still have the hotspot/spill combo. On a dim setting, this is great for navigating a dark house, etc. But try using it to work on something (not a single point) up close for more than a couple of minutes, or try using it to read with for a little while. It can be done, but... The 5mm led flood of the A2 kicks ***! This is what makes hybrids among the most useful and totally underrated lights around.


----------



## rabbit

Thanks Silverfox

My next A2 will still be a white led then!:rock: 




SilverFox said:


> Hello Rabbit,
> 
> I measured the A2 with white LED's at around 40 lux (at 1 meter) on the LED's, my yellow green A2 comes in at around 8 lux. The yellow green is quite a bit dimmer, however for dark adapted eyes, it is great.
> 
> Tom


----------



## glock_nor_cal

No, the flood on the L4 kicks a$$. 
My problem with the A2/white LED was the $hitty tint. The 3 ring beam pattern really bugged me also. Maybe I'm too picky I also seem to recall having another problem with my A2, I'll have to search my old posts, I think it had something to do with water getting into the head. Overall it is a great light no doubt, It just doesn't give me the jaw dropping WOW I get everytime I turn on my l4 in a dark place. I don't think I will ever not own at least one of those lights.


----------



## js

glock_nor_cal,

Phaserburns point was that the A2 has two different types of beams: a low-level LED flood, and a high-level, somewhat tightly focused incandescent beam. Two different types of light, two different types of beams.

The L2, by contrast, has two different levels, but both are the same beam, same light.

The L4, has only one level, one beam.

All three are AWESOME lights. I'm in no way going to enter into the "xxx is better than yyy" with these lights. There are many reasons why a person would choose one over the others. Or a U2. Or a Gladius. Or . . . etc.

But the point remains: the A2 has two completely different beams in one light. Some people find this VERY useful!


----------



## AuroraLite

Hope I am not too late to chime in, but what a wonderful post/read this is! Through and very informative!

I too do love and adore my A2. It is one of my most carried EDC lights, and Phaserburn got it right--the fact that it is a dual-system light which encompass the best of both world really won me over. 

The high output incan has great color retention and throw well for an EDC light(which sometimes led white light might get washed out at further distance) and the multiple 5mms are totally reliable and has long runtime, perfect for close range, battery power conservation and a perfect 'backup' independent system for the higher output. These two 'systems' are just naturally compliment each other really well, and personally, the switch is one of my most favorite switches of all the SF products I have. Buttery smooth 2 stages and totally functional. 

In short, an awesome light and a awesome thread!  :rock:


----------



## carrot

Found more A2 threads in the archives. A lot of unbelievers... and a lot of heated discussion as to whether the A2 would be worth it, just like we're doing with the K2 Kroma now.

SureFire A2 Aviator... availability? price?
what is the A2?
A2 Fever
Surefire A2
More A2 Questions...
A2: First impressions
A2 proto
Boycott the A2!
A2 is starting to ship on Fri
will the SF A2 replace the E2e?
SF A2 $150 US
Al, please respond about the A2
A SF A2 Regulation Question
SureFire A2 Flame-Wars

A few more:
2003 SF Catalog says A2 yields 50 lumens for 60 minutes?
Durability of the A2
Thinking of getting a SF A2. Opinions?

I seem to be getting good at digging out posts from the archives! I haven't gotten to the LED archives yet, but I'm sure I'll find more A2 threads there.


----------



## glock_nor_cal

awesome. they should make a surefire sticky. i'm just wondering what color leds to get if I'm goign to try this light again. I like the white's ability to see other colors in the dark, but i didnt' like its blue tint. i'm wondering if the yellow/green would allow this still, because I know that red or blue will not. i'd use this to navigate at night w/map, etc.


----------



## bonvivantmike

boostmiser said:


> Good write up. I love my A2 too and it's pretty much the perfect light. I bought the black HAIII. As much as I love it, I find myself using the Strion more because it's rechargeable. So, with that said, *what is the best rechargable setup for the A2?*



Yes, I'm also very interested in running my A2 on rechargables. I find I use my L4/McE2S/168S setup much more often because of being rechargable. Has anyone found anything that works, without requiring a resistor change on the LEDs or risking damage?


----------



## js

carrot,

Good links. I think those links cover most, if not all, of the ones I came up with.

You know, at the risk of starting a FLAME war, I'm going to have to say that I was ashamed of the behavior of many CPFers in those older A2 threads. Ashamed. Ashamed and saddened.

It's just astonishing to me that the cognescenti feel betrayed and ripped off and insulted all at once when a new SF light comes out and it is more expensive than they THINK it should be. It's truly as if they feel that we all would have been better off if the option were removed. Like something terrible was committed when we all have the OPTION to buy a light that never existed before. Yeah, what a disservice indeed. Especially for all of us yokels who don't know we're being ripped off. They gotta look out for us idiots, I suppose. For our own good. And argue with us to try to knock some sense into our heads.

Whatever.


----------



## leukos

It was a learning curve.


----------



## Phaserburn

js said:


> It's just astonishing to me that the cognescenti feel betrayed and ripped off and insulted all at once when a new SF light comes out and it is more expensive than they THINK it should be. It's truly as if they feel that we all would have been better off if the option were removed. Like something terrible was committed when we all have the OPTION to buy a light that never existed before. Yeah, what a disservice indeed. Especially for all of us yokels who don't know we're being ripped off. They gotta look out for us idiots, I suppose. For our own good. And argue with us to try to knock some sense into our heads. Whatever.


 
It's funny, and I agree with you, js. Companies price product at whatever the market will bear, going for volume saturation or premium points, as the case may be. That's all there is to it folks; stop trying to figure out different angles. And for those selling here on CPF: stop trying to "justify" your price point. If we're not buying as many as you'd like, lower the price.

Ever buy a bag of popcorn at the movies for $5? (if not, you haven't been on many dates lately or are single; my wife loves "movie" popcorn). Popcorn costs around 25 cents per boxcar or 35 cents per silo. Do you shout in outrage and wonder? No, it is outrageous, but it's still the case because the market will bear the price. Period, the end. It's not that difficult a concept to grasp.

Surefire has a market already waiting when they launch a light. They are reactive to their niche. They do NOT come up with a new light and then say, hey, let's make 10 thousand of these and see if we can sell them... They are pretty much "sold" before they are even manufactured. Because of the market they are in, I'd imagine their product and revenue forecast to be comparatively stable. In short: Like Maglite, I suspect they know what they are doing.


----------



## firefly99

hi Jim,

Your review of A2, is simply in a class of its own.

The Surefire one page manual that came with each light, usually has a diagram of "lamp, tube, batteries, tailcap". It made me wonder why I am paying so much for a "lamp, tube, batteries, tailcap". 

All I am aware of is a Surefire feel good in my hand, look sexy, well built & bright. Now I know what I am paying for.

Please send your A2 review to Surefire, for them to be include in the manual.
Looking forward to your review of other Surefire light. 

Thank you very much  

PS: Just got a A2-WH-HA recently, it is my 13th Surefires.


----------



## bwaites

BTT


----------



## Dan_GSR

another satisfied A2 user here
love the light 

nice review


----------



## glock_nor_cal

Here goes. Red A2 coming my way. lol


----------



## snap

this is my first post and i came for some answers about the A2. got them. I only have one now. I have a E2e for off duty carry, an M3 for work, and a A2 for backup on both. 
what the heck do I buy next?:huh2:


----------



## carrot

snap said:


> this is my first post and i came for some answers about the A2. got them. I only have one now. I have a E2e for off duty carry, an M3 for work, and a A2 for backup on both.
> what the heck do I buy next?:huh2:


Well, in the spirit of this thread, another A2! But if you really want some answers, make a new thread.


----------



## glock_nor_cal

cancel your old card, give the new one to the wife and tell her not to let you near it.


----------



## planex

JS,

Your review was directly responsible for me just placing my first order for a surefire light, the A2 with white LED's. This really sounds like a versatile light. As quickbeam said in his review, if he had something higher than a 5 star rating, he would have given it to the SF A2 :rock: 

Thanks for all the great info.


----------



## Cornkid

Im on the brink... teeetering...
Will it be the Apple Nano 1GB or the A2 (with white or yellow or green LEDs) or the Kroma... Hmmm.

I DONT KNOW>..

DRN IT..

-tom


----------



## ScottyJ

For some reason, I didn't know the A2 was regulated with the incan...now I have to go get one. My wife is going to be pissed at you.

ETA I think Jim is a secret surefire agent planted in CPF.


----------



## Ginseng

But Jim,

The darned thing _only_ makes 50 lumens. 

So that's why the A2 you lent me had the "apparent" 2-level incan behavior. Your explanation clears it up for me in a way that even the electrically challenged can understand.

Thank you for dedicating so much time and effort in writing *The Book of the A2*. It is a joyful paean to a truly brilliant piece of purposeful engineering.

Wilkey


----------



## SCblur

Cornkid said:


> Im on the brink... teeetering...
> Will it be the Apple Nano 1GB or the A2 (with white or yellow or green LEDs) or the Kroma... Hmmm.
> 
> I DONT KNOW>..
> 
> DRN IT..
> 
> -tom



As an Apple fan and a Flashaholic, I feel your pain my friend. That is a choice no one should ever have to make. That's like in bad hostage movies, where the hero is made to choose whose life is spared, his wife's or child's. 

My heart goes out to you.


----------



## magic79

What an awesome review!

I still prefer my L2 for my applications (mostly indoors), but that doesn't discount the utility of the A2 in any way, except I don't like the three separate hot spots in the beam from the LEDs.


----------



## js

magic79,

Thanks!

I too prefer the L2 for indoor applications and if that was the most common situation for me I would EDC the L2 instead of the A2. I actually do sometimes EDC the L2--I'm EDCing it right now as a matter of fact! It's an amazing light.

But for my use most of the time, the incan beam of the A2 is my preference. Both L2 and A2 are rockin' awesome lights, though. How could you go wrong with either one?


----------



## nuggett

Thanks to this thread, I have an A2 on the way. I will post some comparisons with the KL1, KL4 and G2 and M6!


----------



## Sixpointone

JS,

I just wanted to Thank You for this great write up on the A2. It was so thorough, on so many levels, it truly was a great read.

All My Best,
John


----------



## rcashel11

Excellent write-up on the A2! Now I really want one! 

Thank you, js!


----------



## Luna

js said:


> I too prefer the L2 for indoor applications and if that was the most common situation for me I would EDC the L2 instead of the A2. I actually do sometimes EDC the L2--I'm EDCing it right now as a matter of fact! It's an amazing light.




Have you picked up any of the rechargables from AW? Ive been using the L2 more this week (just got them from AW ) and really enjoying it more. Even put the lanyard on it due to the excitement. Considering it has been my brief case light for the last year, I think that says alot.


----------



## wquiles

js said:


> magic79,
> 
> Thanks!
> 
> I too prefer the L2 for indoor applications and if that was the most common situation for me I would EDC the L2 instead of the A2. I actually do sometimes EDC the L2--I'm EDCing it right now as a matter of fact! It's an amazing light.
> 
> But for my use most of the time, the incan beam of the A2 is my preference. Both L2 and A2 are rockin' awesome lights, though. How could you go wrong with either one?


Same here. For most everything indoors I preffer and use other LED lights. Now, for everything outdoors, I am currently using incandecent lights, the A2 always there with me (it is after all my EDC so it is "always" with me anyway!) either as primary light or as a backup light to another incandecent 

Will


----------



## DreamScape

Awesome review Jim and thanks for sharing your knowledge.


----------



## cy

this detail has probably been mentioned before. but I just noticed A2 has a precision pressed collar in body tube.

collar is made out of some type of non-magnetic material. it's pretty hard, so is probably stainless steel. what an elegant way to ensure proper contact between tailcap to body. 

very simular to New ARC4 AAA's stainless contact pin ebedded at bottom of AAA body.


----------



## Arkayne

A+++ thread! Will read again!


----------



## nirad

:rock: :rock: :rock: Excellent review of the A2. Your concise report promted me to aquire one of these versatile illumination tools. I should have one early next week to examine for myself. The anticipation will be hard for me to control until the A2 is finally in my posession.

Thanks again


----------



## Kraeken

Wow. Awesome post! I lurk here a lot, soaking up information, and I have to say this was the most I have learned in one sitting, and I already own two A2's! I am in the process of selling my E series lights, as they are no longer needed. I still keep the C2 around for the Turbohead and the P61. But the A2 goes with me everywhere!


----------



## Manzerick

Ode to an A2! Most excellent!!1


only one problem : you make me want one!!! I"l picking up a M4 really soon but the A2 is not on my radar


----------



## MicroE

JS---Fabulous review of a fabulous product.


----------



## bwaites

Manzerick, it should be!!

Bill


----------



## Draydur

Excellent post.
My 1st quality light... and my !st heartbreaker... those ugly rings.
Did you sand the LED's ? I'm working up my nerve. Don't want to effect resale value. A diffuser or filer works but what fits...?

I got an HDS EDC U60 XRGT a week later and were it not for the incandescent lamp in the A2 and it's allure (voodoo) for me I'd dump the 2 A2 Aviators I bought Green was all the local dealer had but later the new Y/G... Green is too bright and screws up color and contrast. Yellow/green .. the latest and greatest... is really not bad for dark adapted eyes... better (to me) than red).. half as bright as the green.... but those ugly rings.. !!

Sorry, but I want to look at what the light is illuminating, not the beam artifacts. I have the sanding pad and no guts to do the job... maybe tomorrow. The diffuser I ordered won't fit. If it did it would be the way to go.

A-r-rrr-ggg-hhhhh !! :huh:


----------



## bwaites

Draydur,

Sanding the LED's really isn't that big a deal, and worst case, you can send it back to Surefire and have them replaced if it bothers resale. I have two white LED models, and stayed away from the yellow-green for that very reason, the models I saw just had funky artifacts in them.

The HDS is a great light, by all accounts, but the white incan of the A2 is almost just too good to be true!

Bill


----------



## Draydur

bwaites said:


> Draydur,
> 
> Sanding the LED's really isn't that big a deal, and worst case, you can send it back to Surefire and have them replaced if it bothers resale. I have two white LED models, and stayed away from the yellow-green for that very reason, the models I saw just had funky artifacts in them.
> 
> The HDS is a great light, by all accounts, but the white incan of the A2 is almost just too good to be true!
> 
> Bill


OK Bill...
I'm gonna do the Y/g this weekend. It is the right light to have when I jump out of the car in the country and just want to light up some detail. The flip up filter I fitted to my green A2 breaks down the rings and makes the light a 3 stage so I'll see how it goes.

Remember... I know where you hang out !.... LOL 
just kidding ... I've had the sanding sponge for a week.
best
Mike

PS= I cant find the flip up filter I bought locally. It says it's a F0x (blue) but has a large flexable boot and a flip up plastic filter.. very coool.. has bushwacker molded into the rubber.

JS- not stealing your post I hope... Just wanting to talk to some A2 people.

UPDATE: I did the sanding .. very simple to do and the results are Great !


----------



## Manzerick

Talk about typo... My bad folks... I really meant it IS on my radar...

I do want one now... i read my post and was like "hmmm... that's odd"




bwaites said:


> Manzerick, it should be!!
> 
> Bill


----------



## js

****EDIT*** I am wrong. Wrong. Wrong. Wrong. See posts below this for the correct info.*

cy,

Yes. There is a press fit liner, but it is not for improving conduction, in my opinion, despite the fact that this idea was spread around by some pretty damn intelligent people.

No. In my opinion, the liner is there to simplify the machining process and design of the light. If you take the head off the A2, and the tailcap off as well, and look from both ends, you will see that at the head end of things, the inner diameter actually INCREASES once you get past that tapered section that meets with the very top. This inner "lip" is what the LVR3K regulator snaps under to get secured in the light.

BUT, at the same time, if you look from the tail end of things, you will see that the inner diameter shrinks down to like a 1/4" hole that the spring protudes through.

Anyone have any accurate idea about how difficult the section between the top of the head, and that ledge upon which the LVR sits, would be to machine? I'm sure it COULD be done, but I'm also sure that using the top of the press fit liner/tube as the shelf upon which to support the LVR is a more efficient and cost effective solution. Because then you only have to bore out the aluminum rod from the tail end all the way to the underside of that lip that the LVR uses. And that's pretty simple.

I could be wrong, but that's my take on the whole liner situation: it's there for mechanical/structural design reasons, and not for conduction improvement or battery fit improvement.

It's definitely NOT going to improve conduction that much. The tailcap contacts mate with the very butt end of the body, which is aluminum, which is a better conductor than most other metals except for copper, silver, gold, etc. IIRC, it's better than nickel, too. So how could the liner improve conduction? Nah. I don't think so. It could conceivably be there to improve the fit of the 123's, but I also don't believe that because the fit is already too tight. Having no liner would actually improve things.

Anyway, stare at the cutaway shot of the A2 towards the end of the first post of this thread and see if you can't convince yourself of what I am saying.

If not, no problem. It's just my educated guess at the present time. But I feel pretty confident about it.

YMMV.


----------



## Luna

> In my opinion, the liner is there to simplify the machining process and design of the light.



Quite a few of the light have those. I thought they were there for two purposes:

1) prevent the batteries from falling out too easily if you happened to screw the switch to lockout too far

2) minimize cross threading. AL to AL is a bear sometimes and this hardened insert really help to preven a problem.


I cant see it helping out in manufacturing since the CNC setup wouldn't have a problem with this relatively simple design. Manual machining wouldn't be much fun though on.


----------



## CoffeeAchiever

I want an A2 with white LED's in SureFire's HA-III-BK! Fortunately for my wallet, they are no longer available. 

Having just bought an E1e in HA-III-BK, Mrs. CoffeeAchiever would probably boil over if I brought home another SureFire!


----------



## js

Luna,

Yeah. Size15s just emailed me about this. I was thinking that the press fit "liner" was *BELOW* the "ring" looking thing at the very end of the body. But, if the press fit thingy *IS* the ring, then I am totally on board with THAT being exactly what you say it is for. To prevent the wear that would occur on both surfaces with Al to Al, and to improve contact resistance and prevent corrosion and oxides.

Now, THAT makes more sense to me. No wonder. I'm pretty sure that early on, people were talking about a liner or sleeve, and what we are now talking about is definitely a RING. Big difference.

OK. So if I talk to Willie Hunt sometime in the near future I will ask him about this, but it sounds like we now have the definitive answer.

Thanks for mentioning it, Luna. (And Size15s).


----------



## Size15's

The A2/L1/L2 features a ring pressed into the TailCap-end of the body. It extends about 5 mm (I'm not measuring it so that's a guess) inside the body and also has a lip so that it forms the contact surface for the TailCap switch.






The U2/K2 has the same thing only on a more obviously scale:





These rings are made of a Nickel alloy I believe. I underst that this does not oxidise as easily as aluminium alloy and consistancy of resistance is vital to the two-stage switching. There may be some mechanical strength gained because the body wall is rather thin at the TailCap threads.

The U2 doesn't have two-stage switching and the K2's two-stage TailCap will not function on the U2 but it shows that SureFire were planning ahead for future models which I find very cool.

Al


----------



## js

So, the threads on the end of the body are NOT part of the press-fit ring? OK. So there's no thread wear issue / cross-threading issue, then, as Luna was suggesting. It is only at the very butt end and 5 mm INSIDE the rear of the light.

Correct?

Anyway, just to explain what I was thinking before. I was thinking that if the sleeve went from 5 mm down, ALL THE WAY to the positive contact spring, that it had to be there to make assembly and machining easier somehow, because I couldn't think of any other reason for it. I should have known! I didn't LOOK like a liner! But I was assured that the A2 had one by people who should know. DUH. I was not thinking of the same thing they were, obviously.


----------



## tjm

Does anyone know where to find a replacement LED board for the A2. I have a Red A2, but having seen the white, I would like to replace the LEDs. I have seen posts for a DIY replacement of the individual LEDs, but I would like a completed board as 1) I am not very comfortable with a soldering iron and 2) I might replace the Red LEDs at a later date and would like it to be an easy swap.

Thanks,
Tom


----------



## leukos

No luck, tjm, extra LED boards are not available. You might be able to pay a modder to do it for you, but you won't get one from SF without buying a whole new A2. You could also post on the B/S/T to see if anyone with white LEDs might trade with you.


----------



## CroMAGnet

This thread is what Flashaholicism is all about. :twothumbs


----------



## Size15's

js said:


> So, the threads on the end of the body are NOT part of the press-fit ring?


The threads at the TailCap-end of the A2/L1/L2 body are aluminium alloy.
The threads are not part of the press-fit ring.



js said:


> OK. So there's no thread wear issue / cross-threading issue, then, as Luna was suggesting.


The TailCap and body are both the same aluminium alloy. I don't see any reason why the A2/L1/L2 would be any different than other SureFires (such as the E2e or 6P etc) with regards to thread wear / cross-threading. 



js said:


> It is only at the very butt end and 5 mm INSIDE the rear of the light.
> 
> Correct?



Correct.
May be you can see in this photo that the press-fit ring extends inside the body a distance just short of the last thread...





Al


----------



## js

Al,

Perfect picture. Illustrates what you are saying very well. Thanks! And yes, I can clearly see what and where the press fit ring is/goes. Bravo.

Is it just me, or isn't that a complicated body to machine? Look at the "bulkhead" just above the 123's. And look at the inside machining between there and the top of the body. Very impressive to this amateur/ignorati.


----------



## tankahn

Dear all,
Thanks for the enlightening thread. I hurried down to my local dealer checking out the A2. They have the white and red led versions. The red-led beam is spoilt by many visible concentric rings. I took the white. Its blueish white actually. Not dim but not too bright either. A beautiful, well-crafted understated light. Very much like owning a fine writing instrument. I am glad I bought it.


----------



## ANW

l love my a2 (white) it's a great light in high and low settings. It's worth it if your thinking of getting one. :rock: 

I was wondering which A2 LCD l should buy for my cousin flying helicopters for the army over in lraq?:thinking:


----------



## Luna

JS, 
I was mistakened on that. I pulled a light out and looked closer. The area that I thought was pressed in was just a burnished area withouth the chemcote. This actually disappoints me a little.


----------



## js

Luna,

Yeah. I hear you on that. But, you know, SOMETHING has to be going right with those threads and the mating between them, because before I replaced my tailcap, the mating on those threads was getting sloppy and loose. But after, the fit was tight again. And I looked at my threads on the body, and they are still nice and rectangular in cross-section, with no visible wear. So, somehow, someway, the Tailcap threads are wearing in preference to the body threads.

Or at least that is what is SEEMS to me is going on based on my annecdotal evidence. Could it be that the body threads are coated with something even harder than HA? Like Titanium Nitride or something? I would think it would be that, and it looks like Chem Kote. But yet the wear seems to occur on the expendible threads.

Anyone have any ideas?


----------



## Luna

js said:


> Luna,
> 
> Yeah. I hear you on that. But, you know, SOMETHING has to be going right with those threads and the mating between them, because before I replaced my tailcap, the mating on those threads was getting sloppy and loose. But after, the fit was tight again. And I looked at my threads on the body, and they are still nice and rectangular in cross-section, with no visible wear. So, somehow, someway, the Tailcap threads are wearing in preference to the body threads.




I wonder if the hardened piece is still contacting the tailcap threads first, thus alleviating the tendency to crossthread. Then again the o-ring might just be acting like a locating bushing

I'm one of those people that seems to always have to resort to using helicoil with Al and magnesium. If it is strippable, I find a way to booger it up 

On this same note, I really like the gladius but I feel the tailcap threads are the weakest link. Like you said, the A2 (L2 in my case) threads still look perfect an I always have to 'hunt' to get the tailcap threaded. With the gladius, they already show a little wear.


----------



## Patrick

ONE! more addition to my collection!!


Thanks js.


----------



## thk

Dan_GSR said:


> another satisfied A2 user here
> love the light
> 
> nice review



This is the rat ******* who got me into "quality" flashlights. He was the first person I knew that had a Surefire (A2). For some reason, I didn't want the same type so I opted for a U2. I love the light but it's a tad on the big side for EDC. Purchased some more lights here and there but in the end, I recently bought an A2 for EDC duties and I'm extremely satisfied with it.

Currently, I own the U2, a Fenix L1P and L0P, an Arc AAA-P, a Gladius and A2. More often than not, I have the A2 on me and the Arc on my keychain.


----------



## skalomax

Super Nice Pics. Thats why i love these forums:goodjob:


----------



## AuroraLite

Hi, all! Still a great read for the 2nd time and after re-reading the thread, two questions do pop up into mind, hopefully fellow A2 user could sheed some light on these :bow: --

1) I kinda wonder what is the best way to measure the current drawn for both levels of lights of A2(meaning how to measure the led and/or incan current drawn from the battery) since the tailcap is a two staged tailcap?

Is there a particular way I could measure the current from the top of the willie hunt voltage regulator while having connecting wires(or V dropped across a 1 ohm resistor) going into lamp assembly/led rings?

2) If I could figure out 1), then this might be pointless...but as this is my one of my favorite EDCs, I also wonder about is there some kind of 'equation' that could help me to approximate the usage time between the incan and leds:

So how many hours of led usage will reduce how many minutes of incan usage time? And is that convertion time reversible?


Thanks in advance! :thumbsup:


----------



## js

The white LED ring draws 110 mA. It is easy to determine this by removing the tail cap and putting a 10 ohm resistor from battery stack negative to body, then using a voltmeter to measure voltage drop across the resistor.

There is no easy way to measure current drawn by the LVR.

I did it by making a dummy 2x123A "battery" that is really just a short circuit. Now attach a DC voltage bench supply to battery negative and body. Start with about 6 volts DC and gradually dial it back until the incan drops out of regulation. This is the DC equivalent voltage of the lamp.

Now remove the lamp and direct drive it with that same voltage but insert a DMM into the circuit to measure current draw. Voila! Now you know voltage and current for the MA02 at the LVR setpoint.

Good luck!

p.s., there is no way to convert LED time into incan time, because the LED's will run when the incan will not,

BUT, you can convert incan time into LED time. It would probably end up being 25 to 1, I would guess.


----------



## tsask

Here is my most recent reportable Surefire A2 experience:

Today I was working in beautiful bright daylight conditions. During a brief rest stop, break I found myself in a dimly lit establishment.
(No I normally don't have the occasion to frequent such establishments)

Nonetheless I noticed two of the featured entertainers (Topless Dancers) were looking for somehing under a table (NO they were not performing in another capacity) I could see they were looking for something like a lost ear ring small .
At that point I arose, approached, whipped out my trusty A2,:naughty: hit those beautiful GREEN LEDS, WOW how cool!! then I turned it up a notch with that brilliant regulated white incan light. The ladies were impressed. glad I was able to help!
My A2 ROCKS!!!!!


----------



## AuroraLite

js said:


> The white LED ring draws 110 mA. It is easy to determine this by removing the tail cap and putting a 10 ohm resistor from battery stack negative to body, then using a voltmeter to measure voltage drop across the resistor.
> 
> There is no easy way to measure current drawn by the LVR.
> 
> I did it by making a dummy 2x123A "battery" that is really just a short circuit. Now attach a DC voltage bench supply to battery negative and body. Start with about 6 volts DC and gradually dial it back until the incan drops out of regulation. This is the DC equivalent voltage of the lamp.
> 
> 
> 
> Now remove the lamp and direct drive it with that same voltage but insert a DMM into the circuit to measure current draw. Voila! Now you know voltage and current for the MA02 at the LVR setpoint.
> 
> Good luck!



Js,

Thank you for the advise, being a EE dummy, I think I should be able to manage the tailcap part no problem. But the sucky part is I don't have a DC voltage bench supply handy, and is there any way I could work around without it? (off topic, any good suggestion for a DC volt bench supply?)

Also, out of curiosity, will the lit up led ring affect the accurate reading for the bulb when it drops out of regulation? :thinking:



js said:


> p.s., there is no way to convert LED time into incan time, because the LED's will run when the incan will not,



Actually, what I'd like to find out is if I use solely the leds of A2 for X amount of mins(or hours), how much usage time I could expect left for my A2 to lit up before it drops out of regulation? or vice versa...

(see below, will my following dummy method work?)




js said:


> BUT, you can convert incan time into LED time. It would probably end up being 25 to 1, I would guess.



25 to 1, do you mean approx 25 hours of led usage = 1 hours of incan time?

That got me thinking--if I measure how long it takes for the incan drops out of regulation and the Vbatt then(say exact 50 min and the battery voltage reads 1 volt)...

And then I put in another new set of batteries, and I measure how long it takes for using the leds only to reach the same Vbatt(say battery voltage reach 1 volt after 24 hours sole usage of led usage)...will it mean the conversion time is approximately 50/1440 min between the incan to led usage time?


In another words, approximately, we might get

Used incan time = Used led time x 50/1440 Or
Used led time = Used incan time x 1440/50

Errr....am I way off track or I am getting close? :sweat:
Another thanks in advance! :bow:


----------



## js

AuroraLite,

The situation is very complicated because the voltage of a battery under a load is dependent on exactly what the load is. So 1 volt/cell under the incan load, will mean higher than 1 volt/cell under LED load. Plus, the cutoff voltage for the incan is definitely higher than 2 volts!

What are you trying to find out? How many minutes of incan runtime you lose by using up 1 hour of LED runtime? If so, why not actually just try that test? Take new 123's and run the LED's for 1 hour. Then switch to incan and see what you get for runtime. Then do the incan only test and check that runtime. Next try 2 hours of LED runtime and see how that affects things. And so on.

Just beware that 123's can come in different states of charge straight from the manufacturer, unfortunately.

As for current draw of the incan, don't worry about it. Why does it matter? Knowing the equivalent DC amps of current draw is more or less worthless information, because the A2 regulator is NOT putting a DC current through the lamp. And the dynamic load on the batteries can't easily or completely accurately, be translated into a steady state load. Plus the voltage advantage of the battery stack vs. the lamp voltage set-point translates into a reduction in the current draw from the batteries, such that power in = power out, approximately. (Within 2 percent, anyway). Thus Vlamp*Ilamp = Vbat*Ibat. But here again, you have to be careful about whether you are talking about instantaneous values or averaged ones, and what the averaging time is, and so on.

The lamp draws about 5 or 6 watts of power, approximately. And the setpoint of the LVR is somewhere in the neighborhood of 3 or 4 volts DC-equivalent. (There--that should be vague enough!)

But why does having the exact numbers matter? Why do you need them? Having them probably wouldn't help you! Don't bother buying a bench supply. They aren't cheap. Just use 1/10th of that money to buy a bunch of 123's and do the experiments. That is the most accurate and informative way to do things.

And when you find out, let us all know! We'd love to hear what results you get. AFAIK, no one has done this experiment on the A2--at least no results have been posted to CPF regarding it that I know of.

Good luck!


----------



## sween1911

This is an awesome thread. Makes me suddenly realize that I saw an A2 in the Used/Bargain section on the first floor of Cabela's in Hamburg, PA. I tried it and only the green led's lit up. I think they wanted like $100 for it or something.

The A2 is certainly an awesome light. Appeals to the side of me that likes versatile things that can accomplish many different tasks.


----------



## AuroraLite

js,

Thanks for the reply, though as a EE dummy I don't have exact idea how exactly the LVR trying to regulate the voltage, but I do understand the complexity of how the dynamic load on the battery might not allow a straight answer to my question. By the end of the day, it is true that it probably really doesn't matter how much current it draws if the current drawn is dynamically changing overtime. :shrug:

Personally, when using the U2, I find it 'comforting' to know approximately how long each level of light will be remained regulated, for example I might be able to approximate/assume the remaining regulated runtime of the highest level left if I am half way thru with the regulated runtime of second highest level of light...and as for my A2, I know the led will lit even when the incan is gone(of course, the leds output then will probably be much lower than when the batteries are all fresh), and more important a question for me is how much led usage time will reduce the remaining incan runtime(so I won't be stuck with the low light without knowing when I do need the high light). :thinking:

From your suggestion, just like what I have suspected--there is probably but one way to find out for sure--is to do multiple tests by using the leds first, and then measure how much incan time was remaining afterwards. 

Hmm, I wish there is a less wasteful way, but nonetheless, I would try to find time to perform those tests at certain intervals(for now, maybe every 2 hours of led usage time, and then measure how much incan time left) to try to determine the correlation between the two. *If anyone is interested to help*, please do post here(or your data gathered) or pm to let me know...I shall report back when I find more info.

Btw, I visited willie's page about the LVR, and I now wonder which version/kind of LVR is used for the SF A2(or what is the max voltage in for the SF A2?)? I have heard numerous time that the LVR is a buck design, and that piece of info would help my next A2 leds swap, since I am finally considering putting in higher values resistor for making my A2 rechargable friendly...

Thanks again, and I have truly enjoyed the discussion on this fine piece of equipment/toy!


----------



## js

The A2 has an LVR specially designed for it: the LVR3L. All of the LVR's will accept up to 2.5 times the regulation voltage. So, to be conservative, say 8 volts input is maximum. So two R123's Li-ion cells is definitely the limit. Three would be crazy. Not that you could fit three or anything! But empirically, lots of people have been running 2 R123's in their A2's and the incan side of things is holding up. There have, however, been a few reports of people burning out or damaging their LED's due to the excess current forced through the LED's (due to the higher input voltage).

As for help, normally I would do at least one data point for you, but I'm pretty busy lately so for now I'm going to hold off. At a later date, however, I may be willing to do a couple test runs and provide a data point for you (assuming that any testing work remains to be done by then).


----------



## bwaites

The white A2 LED's run for more than 24 hours on one set of batteries.

I suspect that each of the different colors will run a different amount of time, since Red LED's require less current than white, and the green/yellow are much dimmer to start with, etc.

However, for my purposes, I simply subtract 5 minutes of incan runtime for every 2 hours of LED run. I know, I know, it's really rough, and as you go over 15 hours, the incan really doesn't want to light, but it's good enough for me.

Bill


----------



## faucon

Wow, this is the most detailed review/post I've ever seen. It reads almost like a research article as well as being very persuasive. I hadn't even considered an incandescent until your post. Now I'm going to seriously consider an A2. The only thing that might make me hesitate is the unpredictability of the bulb's blowing, and having to stock extras. But your post makes these concerns seem worth it for the features you get. Thanks!


----------



## AuroraLite

Js,
That's great info about the LVR, do appreciate it and am sure I will find this thread whenever I am ready to mod the A2 to go rechargable. :thumbsup:


Bwaites,
Excellent, that is the kind of info I was trying to guesstimate/find! :rock: :goodjob: I do have a few A2 with different leds(red, white, modded SMJ) and I think to conserve battery, I will conduct the test differently based on your suggestion:

A set of battery put into normal white A2 and SMJ A2, turn of the led and let it run...and on hourly(or bi-hourly) basis, I will turn on the incan for 1-2 sec to see whether it will lit up. I will record the Vbatt at the beginning and Vbatt and the duration it takes when the incan no longer want to lit...from past experience, I am almost certain that my SMJ A2 incan will not lighting up long before the normal A2 since it has a much heavier current drawn (235ma vs 110ma). 

And when I got more time, more tests on the original design of the test, which I will run the A2s for certain hours with leds only, and then turn on the incan and measure the remaining usage time for incan.


faucon,
I used to have one A2 long long time ago, and it was just collecting dust in a drawer since I felt it was too long to EDC. But then after EDCing my modded other SF or Aleph lights for a while, I notice the A2 is actually extremely versatile for the dual incan and led system and it is totally EDC-able. And more so, I really like the idea of having these two independent systems which is a surefire way to make sure I have the light when I need it. 

The bulb is a valid concern, but as Js said earlier in the thread, constant incan usage is probably not how most SF A2 user use their light, and with the soft start and most usage on leds, the bulb will last a really long time.


----------



## bwaites

I have 2 A2's, one for nearly 3 years, and have yet to blow a lamp. I'm not sure how many sets of cells.

My brother-in-law carried one in Baghdad for a year, at least 50 sets of cells by his count, never blew a lamp.

The A2 is easy on lamps, apparently.

Bill


----------



## dragoman

Guess that soft start feature works........

On 5th set of batteries now, no problems yet....

dragoman


----------



## js

I put 50+ sets of batteries into my first A2 lamp over the course of a year. I have dropped it, knocked it, and at least 90 percent of the battery capacity was used for the incan = 37.5 hours or more of incan running. And it was still good to go and working fine--EXCEPT that when I got my second A2 (from bwaites  ) I noticed that his was brighter by a little bit. So I pulled the lamp from my A2 and noticed that there was a slight bit of darkening of the glass envelope. This is due to the fact that the MA02 is a xenon/halogen lamp that is pretty light on the halogen in order to be pretty HIGH on the pressure. For the highest pressure xenon lamps, a halgoen would start to corrode the filament itself, or the filament supports (I can't remember which). But if you put enough of a trace amount of halgoen in to COMPLETELY eliminate blackening, then you must lower the pressure. And a lower pressure equates to a lower efficiency and a lower CCT.

SO, SureFire compromised and made a lamp that is very slow to blacken but in exchanges, pushes up the efficiency to near the maximum.

Anyway, point is that the lamp is pretty long lived and seems to me to be pretty rugged, although I've never dropped my A2 on concrete while it was lit. Thank goodness!

So, yes, the lamp IS an issue--it IS an incan, after all. BUT, it's a price well worth paying in my opinion. $30 a year for a new MA02 isn't that big a deal. Not when that equates to $100+ in batteries. And, plus, I could have kept using my old MA02, but I wanted the 100 percent brightness again. I suspect that I could have put another 50 sets of 123's through it before it burnt out or was down to 75 percent brightness. Just a guess though. And, also, consider that over that year the A2 was my constant companion and EDC light. I used it a LOT. If it were part of an EDC rotation, or sat next to my bed most of the time, or in a glove box, or etc., then the lamp would have lasted a lot longer in terms of months/years.

Anyway, thanks everyone for your kind words about this thread/review!


----------



## Size15's

I've put over 45 sets of SF123A batteries though an A2 over the course of a few months. The bulb is still shining bright and white although some discolouration had begun to occur inside the bulb so I swapped it out for a new lamp just to be safe (afterall the discolouration is bits of filament)

Al


----------



## ANW

Wow the A2 is one interesting light, it's probally why i'm looking to buy a few as gifts for Christmas. But I should buy/order myself a backup Bulb for my A2 just in case the incandecent should go, but having it for two years and daily useage it's still going bright and strong after few battery changes. I'm so glad l bought one it was well worth it.


----------



## js

ANW,

Yes, in my opinion it's *always* a really good idea to have backup lamps for every incandescent light you own. I try never to be without a backup lamp. That way, if my main one burns out or seems to be losing a bit of brightness, I can swap in the spare and order a new spare, instead of waiting for a spare to swap in. It's just a plain good idea--be prepared and all that.


----------



## AuroraLite

Hi, everyone.

Back with the result for the first test, and posted it on my Dummy Reference Guide to SF A2 modding with higher powered leds --

Here is the extract:

Today, I did two experiments, one is to find out when the incan fails to regulate, the V of the battery and how many hours of SMJ led usage time will cost my SF A2 fails to lit up the incan.

For first set of my old batteries(which was originally in my A2 already), I run the A2 with incan until it fails to regulate(or if I turn it on and off, it will fail to regulate), and I measure the V of the battery, and they read around 2.75v each(panasonic CR123).

Then, I put in two brand new panasonic 123 batteries(~3.26v ea) and turn on solely the led on A2, and after each hour usage of SMJ leds in my A2, I would turn on the incan for approximately 5 secs to see whether it will fail the regulation. That way, I would know how many hours of SMJ led usage will make my SF A2 incan fail to start...

After 9 hours of continuous use of SMJ leds in my A2, the incan failed to start/regulate.(but after 8 hours, the incan lit up perfectly for the 5 sec test). The V of batt reads ~2.645v each. So it probably will be safe to assume the incan will stop working sometime after 8 hours straight usage of SMJ leds.

If we were to assume the incan usage time is perfectly 50 mins, and conservatively, the 8 hours of SMJ leds usage will cost the A2 fail to regulate/lit up the incan...then *my rough educated guess will be for every 1 hour of SMJ leds usage in my SF A2, it will cost approximately 6.25 min of incan runtime.*

####################################################

Bill has the rough guess of around 5 min incan time in trade off with 2 hours of led usage time(for a normal A2)...or his observation of 15 hours of led usage time will cost the incan start to not willing to regulate. 

In other words, each hour of led usage time for a normal white led A2 will mean around 3.3 min incan usage time trade off(based on the 15 hours figure)...which sounds about right to me since I measured 208ma current drawn for my 3 SMJ leds, meanwhile Js got a reading of 110ma for the 3 normal white leds in his A2...which my battery would deplete its power almost twice as quick, causing my modded SF A2 will fail to power up the incan to regulate sooner. :goodjob: to Bwaites and Js for the rough numbers/data!

Anyway, those are my initial findings, I will do more testing and maybe some testing on my original white A2 as well.


----------



## js

AuroraLite,

Nice work! Thanks very much!


----------



## ront

Awesome review js!! It pushed me over the edge. I soo will have one on the way from "oldgrandpajack".

Ron


----------



## faucon

Js, AuroraLite, and Bwaites et al,

Thanks for the info and thoughtful reasoning. I hadn't realized that the SF bulbs are after all pretty long-lived compared with run-of-the-mill incandescents. Part of my former bias against incans was due to memories of having my Maglites blow out at just the wrong moment one too many times. But of course a Surefire is a much better engineered piece of equipment. I'm glad to have been 'enlightened' and now have a much more open mind.


----------



## woodfluter

bwaites said:


> What the A2 does that no LED so far has done is color rendition, as Jim mentions above.
> 
> I like my U2, I like my U binned Aleph3 with two stage, but the A2 is the light that goes EVERYWHERE with me.
> 
> Bill



I should start by saying that I don't have an A2, so am massively ignorant from a perspective of direct experience. However. Jim presents photos and asks us to reach our own conclusions...with caveats that the A2 isn't quite as red as it appears and the L2 (which I do have) isn't quite as blue. So, I see much more difference in leaf colors and tones in the L2 photo. Do you? Those differences are evident in the daylight photo. The A2 photo appears strongly red-biased and more uniform.

Secondly, bearing in mind that everyone's night vision is different, I can go from staring at a computer screen to stepping outside with L2 in hand, pacing off distance in darkness, and with assurance could easily identify a coyote or something similar at 250+ feet. And if allowed time for night-adaptaion, my vision would normally be 2x or 3x as sensitive, at a minimum.

Not that the L2, with its wide flood beam, would be my first choice for such a task.

Apart from those quibbles, wonderful and well-written post giving us all more appreciation about what goes into these techno-marvels. And yes, I agree that they are not over-priced. Surefire does fine work and deserves to be fairly compensated.

- Bill


----------



## js

woodfluter,

Thanks for the kind words on the review!

First of all, yes, the L2 is a great light, and you can do a lot with it, even using it for tasks for which it is not ideally suited. Granted.

However, whatever the pictures may show on your monitor, I can tell you that for almost ALL outdoor situations, the A2 wins at color rendering hands down, no contest, --at least to my eyes. The camera, combined with variances in different computor monitor color renderings, conspire to make beamshots fairly unhelpful to show color-rendering capability. This is why I told people to decide for themselves. Not because it was a close call or anything(!) My main goal in that section was to show the THROWING ability of the three lights, and nothing more, because I felt that the aspect was not well documented. I would have to get one of those color charts and a better camera if I were going to try to document the A2 vs. L2 CRI.

For me, the L2 is very unpleasant for outdoor use. I feel like I am walking on the moon or something. Indoors, I don't get that sensation. But outdoors, I just don't take well to the ghostly white, insubstantial LED light.

However that may be (entirely personal taste), I would be very surprised if you actually pace off 250+ feet and then do a throw test and find that the L2 is satisfactory at that range. It isn't in my opinion, anyway. But even if you do find it is good enough, the point is that the A2 would be WAY better.

Doesn't mean the A2 is the better light, just means that the A2 throws better. The L2 does a lot of things better than the A2, though, no question. I just wanted to present the A2 in its strong points to balance out all the other information out there.


----------



## woodfluter

Thanks Jim, points well taken! I am sure you are correct, and I do know the limitations of color photos on monitors. (With digital, I like to do a color balance and lock that in - no automatic exposure! to compare, and that comes out fairly close to what I see.)

Now I'm finding myself faintly lusting after the A2.

Do tell though, in your opinion, is the beam seriously affected by the intrusion of the LED's into the reflector? Please excuse me if this has been addressed, I looked quickly through all the posts but didn't see any lengthy comments on that.

- Bill


----------



## woodfluter

js said:


> For me, the L2 is very unpleasant for outdoor use. I feel like I am walking on the moon or something. Indoors, I don't get that sensation. But outdoors, I just don't take well to the ghostly white, insubstantial LED light.



Yeah, tastes vary. I'm used to walking by moonlight and find that pleasant, which might explain why I don't mind the tint. But I certainly don't question the A2's throw advantage.



js said:


> However that may be, I would be very surprised if you actually pace off 250+ feet and then do a throw test and find that the L2 is satisfactory at that range.



Now for the reason I am posting again - and my apologies for being unable to resist! Tonight took the dogs down the street to the nearby church property, back end of which is open and unlit. My Hannah is a husky/unknown mix, slightly larger than the putative coyote but very much the same color scheme - only notable difference being one erect ear and the other flops, plus curly tail. Tied her to a bench and paced off 250 feet. Had with me SF L1 and L2. Without light, Hannah and the bench are quite invisible. 

Now the L2 on high beam reveals her reasonably well, certainly clear enough to ID her as a dog. But the largest disadvantage, offsetting theoretical throw, is that the wide and very bright beam craps out my dark adaptation instantly. My pupils contract due to the illumination of moisture in the intervening atmosphere. Much better when the light is held at waist height, very bad when held above my head (particles are lit which are directly in the path of returning light).

Using the spot-illumination of the L1 (which does have slightly better theoretical throw), there is far, far less pupil contraction. Hannah is clearly identifiable as an individual, including curly tail and one flop ear. At 250 feet, accurately paced by a professional geologist and sometime orienteer. Perhaps having somewhat doglike eyes?

I point this out not to refute, but more to emphasize something that is often missed in discussions about throw and output. There just isn't any perfect light for every purpose and there are a lot of compounding factors at play. The L1 wasn't just marginally better for this task, as the throw figures would indicate, but much better due to the narrow beam. I do wonder how A2's beam compares.

All the best, 

- Bill


----------



## maverick

woodfluter said:


> Do tell though, in your opinion, is the beam seriously affected by the intrusion of the LED's into the reflector? Please excuse me if this has been addressed, I looked quickly through all the posts but didn't see any lengthy comments on that.




That's a very interesting point you bring up. I've used the A2 on a regular basis for work for about 2 years now. From normal use, I don't really notice a degradation of the incan beam quality from the presence of the LEDs. However, when I shine the incan beam at a wall maybe 2-3 metres away, I do notice a difference between it and other Surefire beams. Compared to a similar powered Surefire light such as an E2E, the A2's beam appears to be somewhat more diffused and less defined. This is especially noticeable around the edges of the beam. Also, the centre spot does not appear to be as round whereas the E2E's beam is very close to perfect. I totally agree with JS about the excellence of the A2, and being a person who owns many Surefires, the fact that I've used solely the A2 for the last 2 years definitely says something about its strengths. Looking at the placement of the A2's LEDs within the lamp assembly, I think it is obvious that the incan beam will be affected somewhat. But I consider this sacrifice necessary to give the A2 its versatility we all love. Notwithstanding, the A2 is still one great light and I for one will continue to use it. 

JS, a very informative review. Well done!!


----------



## a99raptors

Thanks for putting another hole in my wallet JS! Just got mine and I can see why you managed to write a technical manual on the Aviator


----------



## Blindasabat

maverick said:


> Looking at the placement of the A2's LEDs within the lamp assembly, I think it is obvious that the incan beam will be affected somewhat.



I was thinking that SF might make the next generation SF use smaller LEDs so it doesn't need such big holes in the reflector. New generation 3mm LEDs with same brightness perhaps put further out at the edge of the reflector (if that location works better). I'n not saying that the A2 beam is bad, just that I've noticed is is not round.


----------



## bwaites

It won't be round!! The best THROW for an incandescent actually occurs when the length of the filament is reflected in the shape of the hot spot.

You can make the hotspot round, but you sacrifice throw.

As far as the LED's intruding into the incan beam: It is noticeable up close on a white wall, but at more than 5-10 feet, it has no real impact. The reflector designers did a great job combining the shape of the reflector and the orange peel to alleviate those artifacts.

In the REAL world, (meaning the non-white wall hunting group) the A2 is as close to perfection as a little light gets!

Bill


----------



## Blindasabat

bwaites said:


> It won't be round!! The best THROW for an incandescent actually occurs when the length of the filament is reflected in the shape of the hot spot.
> You can make the hotspot round, but you sacrifice throw.


Yeah I understand, I guess I don't really need round, but my A2 is oval, such that I turn it to be horizontal to line up with my horizon, but I am more demanding than most. And still not a big deal given it is much better than many other lights I have. 



bwaites said:


> As far as the LED's intruding into the incan beam: It is noticeable up close on a white wall, but at more than 5-10 feet, it has no real impact. The reflector designers did a great job combining the shape of the reflector and the orange peel to alleviate those artifacts.
> In the REAL world, (meaning the non-white wall hunting group) the A2 is as close to perfection as a little light gets!
> Bill


I agree Bill, I only figure if they can get more useable reflector area, more incan beam will be reflected forward for improved throw (not that it's bad now, it it actually better than rated by FLR in my opinion). I'm not so worried about artifacts either. My more often used A2 LEDs have artifacts on a white wall, but not in real world use either.
I don't even pretend to say these are things SF should do or that they will work, just ideas and speculation of what seems logical. Being an engineer, I can't help but look at something and see how it could be improved.


----------



## bwaites

Blind,

Improve on perfection? Only an engineer!!

But really, there just isn't much surface area to work with. I suspect that they've put those LED's as far out as they can and still have them attach to the the board with some modicum of reasonable support.

You could enlarge the reflector, but that just gets you a bigger light, and one of the best things Surefire did was keep it this size. The U2 is too big to EDC for me, though I know some do. 

Maybe by using 3MM LED's they could decrease the instrusion, and with some of the advances in LED tech recently, they probably wouldn't lose anything, but as it is, it is so good that I'd hate to see much messing with it. 

I have had my stock "white" LED's replaced with newer, smoother 5mm LED's and that is an improvement, with less of the "angry blue" look to the beam and a much smoother flood, almost completely without any artifact.

Bill


----------



## js

woodfluter,

OK! Good stuff, and good to know that the L2 will reach out that far. Thanks for doing that and reporting back. Sorry I doubted you! I've never tested the L2 throw that far out, and it surprises me. But then again, I'm probably a bit more fastidious in how far I will say a given light will throw. I really want it to clearly illuminate the target while at the same time not ruin my eyes with too much nearfield light. That's one of the reasons I love my TigerLight so much: it has such a nice balance of spill vs. throw (with the emphasis on throwing ability, however).

On another note, yeah, I agree with the 3mm LED suggestion. There is no question that those three holes in the reflector are NOT a good thing. If they were smaller, that would help, although, as mentioned, even as they are, they don't affect the beam too much. It's really quite amazing. I never would have guessed at how well SF could get around them and end up with such a nice beam--considering. Although, for beam profile perfection (shape and smoothness), the E2e is in front of the A2 by a noticeable margin. But the A2 has a whiter, higher CCT beam.


----------



## Luna

a99raptors said:


> Thanks for putting another hole in my wallet JS!




I hear the rechargable Beast is his next expose so time to call in the bankers


----------



## a99raptors

Wonder if I can mortgage my arm and leg.... :laughing:


----------



## carrot

Hey if you sell a few organs you can easily afford a Beast Rechargeable... a kidney and lung will fetch a very nice price on the black market.


----------



## a99raptors

carrot said:


> Hey if you sell a few organs you can easily afford a Beast Rechargeable... a kidney and lung will fetch a very nice price on the black market.


 Sorry, need the lungs to go "Ahhhhhh...." when I turn on the Beast.
Need the kidneys too, when the money leaves my hand....


----------



## js

Rechargeable Beast expose? Holy cow! No way. That would mean I'd have to BUY one, right? Too rich for my blood.

No. My next thread along these lines will be the "TigerLight Owners Manual" thread. And also part 2 of this thread, possibly,maybe . . . eventually. LOL.


----------



## Codeman

js said:


> Rechargeable Beast expose? Holy cow!  No way. That would mean I'd have to BUY one, right? Too rich for my blood.
> 
> No. My next thread along these lines will be the "TigerLight Owners Manual" thread. And also part 2 of this thread, possibly,maybe . . . eventually. LOL.



Oh, man, you're just like 24. Leave us hanging after a great season and then make us wait for the next installment!

Or....is this like a good whiskey that needs to age before it's ready?


----------



## SilverFox

Hello Blindasabat,

If you are interested in getting the maximum throw from the A2, take the LED ring out.

We have an A2 included in our Light Meter Benchmarking Testing pass around. It has the LED ring removed for the purpose of our testing. I noticed that the A2 without the ring was showing higher lux than my A2 with the ring. I replaced the lamp in the A2 without the ring with my lamp and still showed higher readings than when the lamp was in my A2 with the LED ring.

I measured a difference of around 200 lux. I am not sure what is causing this increase. It could be that removing the LED ring allows more power to drive the lamp, or it could be that the LED's are absorbing some of the beam. It is probably a combination of factors.

At any rate, an extra 200 lux works out to around an extra 14 meters of throw.

Tom


----------



## a99raptors

SilverFox said:


> Hello Blindasabat,
> 
> If you are interested in getting the maximum throw from the A2, take the LED ring out.
> 
> We have an A2 included in our Light Meter Benchmarking Testing pass around. It has the LED ring removed for the purpose of our testing. I noticed that the A2 without the ring was showing higher lux than my A2 with the ring. I replaced the lamp in the A2 without the ring with my lamp and still showed higher readings than when the lamp was in my A2 with the LED ring.
> 
> I measured a difference of around 200 lux. I am not sure what is causing this increase. It could be that removing the LED ring allows more power to drive the lamp, or it could be that the LED's are absorbing some of the beam. It is probably a combination of factors.
> 
> At any rate, an extra 200 lux works out to around an extra 14 meters of throw.
> 
> Tom


 Wow! That's interesting. I could remove the LED rings and run it on 2 unprotected R123s..... Rechargeable, Regulated, Brighter Incand


----------



## Blindasabat

Dudes! I was just bench engineering, thinking out loud what SF might do on the next evolution of the A2. I love mine and wouldn't modify or part with it for anything. I like and use the LED's; they are great where and how they are. I would just imagine getting a _new_ A2 if some improvements were made, because then it would be _more_ perfect. If SF comes up with a way to further minimize the effect of the LED's on the small reflector and keep the head small, then all the better for us.



SilverFox said:


> Hello Blindasabat,
> 
> If you are interested in getting the maximum throw from the A2, take the LED ring out.
> At any rate, an extra 200 lux works out to around an extra 14 meters of throw.
> 
> Tom


----------



## bwaites

Blind, we're just yanking your chain!

Believe me, Jim, Tom, and I, have all played the "What If?" game with the A2 for hours on end!!

Bill


----------



## Luna

Speaking of armchair engineering,

the best way I found to implement max throw with muliple sources outside the center axis is to have what is basically a TIR optic that surrounds the reflector. So externally you see an ring of light around the reflector. The leds feeding the ring would be hidded inside the head.

Ask me why I've been learning about more about acrylic optics....


----------



## Bullzeyebill

Luna, why have you been learning more about acylic optics?

Bill


----------



## Bullzeyebill

Didn't someone experiment by covering the led holes to gain more output and throw? Not sure what could be used to cover the holes.

Bill


----------



## McGizmo

bwaites said:


> Blind,
> 
> 
> .....
> Maybe by using 3MM LED's they could decrease the instrusion, and with some of the advances in LED tech recently, they probably wouldn't lose anything, but as it is, it is so good that I'd hate to see much messing with it.......
> 
> 
> 
> Bill



They wouldn't have lost anything in the initial design had they used the Nichia 3 mm LED's. Nichia uses the same die in their 3 mm and 5 mm packages. There is a NSPW312 that Darell and I rallyed PK to consider back on the SF web sight but the putz ignored us.  PK did put some in a couple A2 turbo's but most unfortunately, that project got cut from the lineup. There are some new MSPW310-CS LED's now that are very bright and excellent in artifact free flood. If I were to build a new LED ring for one of my A2's I would use these. Their smaller size would have less impact on the incan and reflector I would suspect.


----------



## carrot

McGizmo said:


> PK did put some in a couple A2 turbo's but most unfortunately, that project got cut from the lineup.




I have to have one!!!


----------



## bwaites

So...How about a McGizmo mod with a MicGizmo reflector and the 3mm LED's?

Come on Don, you know you want to do it!!

Bill


----------



## Luna

Bullzeyebill said:


> Luna, why have you been learning more about acylic optics?
> 
> Bill


----------



## Size15's

carrot said:


> I have to have one!!!



There aren't many proto-types. I know somebody who has one. I don't have one myself. After I saw one I didn't feel it gave significant benefit for the increase in diameter so I didn't try to steal one from PK.

Al


----------



## Codeman

This thread's is too good to not be near the top.


----------



## boostmiser

I've got a ???
What's the significance of the purple A2? Why did they make it?


----------



## js

boostmiser said:


> I've got a ???
> What's the significance of the purple A2? Why did they make it?



They made for Size15s so he could put a picture of it in his sigline and make all the rest of us INSANELY jealous. LOL! j/k.

Seriously, though, I can't remember what the deal was with that, although I think I read about it once. I'm sure Al or similar will tell us shortly.


----------



## greenLED

greenLED said:


> Man, I just re-read this, and I'm one step closer to wanting one. I'm not sure if my wallet thanks you, js (I sure do! )



There you go!

Thanks to this thread, carrot's insistence (and keeping an eye out for me on BST), and bwaites and rscanady who let me borrow their A2's to try out, I am now a proud owner of an A2. An A2-BK, to be exact. 

Now that I own an A2... if I had to choose which of my SF's to keep (GULP!) it'd probably be the A2 (the U2 coming in close at second). Too versatile!


----------



## Size15's

I get the impression that people at SureFire (for example PK usually) like to have fun and are often amazingly generous with gifts. The purple A2's were made for fun by PK and a friend of his Dealer purchased them and I was lucky enough to buy one from him. I believe about 7 or 8 were made in total.

Al


----------



## this_is_nascar

Although a great collector's item of a great light, I don't care for the looks of the purple A2.


----------



## dizzy

I would like to get a BLACK A2 when I do get one, which I hope will be soon. 

Anyone looking to unload one?


----------



## Bullzeyebill

I think the purple A2 is just fine. I know that my daughter, Ruth, would love to have a purple A2. Purple anything.

Bill


----------



## boostmiser

Size15's said:


> I get the impression that people at SureFire (for example PK usually) like to have fun and are often amazingly generous with gifts. The purple A2's were made for fun by PK and a friend of his Dealer purchased them and I was lucky enough to buy one from him. I believe about 7 or 8 were made in total.
> 
> Al


Cool. Not my style, but at the price they're going for (saw one sold a few days ago in the classifieds), I wouldn't mind having one.
Oh, and is it just annodized or is it HA whatever?


----------



## seery

js - Very informative, Thank you. 

The choices (and reasons for choosing) of color for the LED didn't seem to
come up often in folks responses.

This A2 will be used mainly when I need some light but don't want to take away
from my night eyes. ie. Hunting, fishing, night hiking, etc.

A search didn't turn up much.

Looking for folks specific feelings/comments/experiences on the different colored
LED's. Output? Quality? etc.

Thanks and looking forward to joining the A2 crowd.


----------



## Codeman

The white LED's have the best beam - a nicely rounded hotspot and therefore brighter. The others give kind of an Olympics rings beam. If you need a specific color, go with that. If not, then I'd recommend the white LED's. The difference in beam quality is like night and day.


----------



## ruledpaper

I've got a blue one and I think the LED color and resulting artifacts would be the only reason I would ever want another light.

The search function is being a major pain right now, can anyone point me in the direction of the pimp my A2 thread? I would love to add on a rubber combat ring and sand the LEDs, maybe even switch the LEDs out for brighter white, or something cool and gimicky like UV. Boy, that would sure burn someones eyes out.


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## carrot

Leukos' A2 Tune-up thread

Oregonshooter's A2 switch guard rings and combatgrips


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## greenLED

carrot said:


> Leukos' A2 Tune-up thread
> 
> Oregonshooter's A2 switch guard rings and combatgrips


If I may add:

*Dummy reference guide to SF A2 modding with high output 5mm leds

*SF A2 - I found an Easter Egg!!


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## EasEWryder

"This concludes the first part of my discussion of the SF A2."

Dude, you absolutely :rock:


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## js

Thanks, EasEWryder. 

It's more a case of me being a bit crazy. At least according to my wife, anyway. Reminds me of SilverFox's sigline. hehe.


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## marxs

i dont know how long it took you to compile and/or write this...but this is one piece of writing executed perfectly :goodjob: (though i wouldnt mind you discussing black bodies, color temperature and spectral peaks).....this should actually be part of the a2 manual :laughing:


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## clipse

I was on the fence as to whether or not I want an A2.........this thread did it for me. I'll have one on the way soon enough. 

clipse


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## Donovan

Since the A2 has been around (2+ years?) have the LED's been upgraded at all by SF? What LED's do they use? Have there been any changes to the light since its debut?


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## marxs

im not sure if the leds have been upgraded yet, but they are using nichias for sure. a quick call to sf maybe?


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## Galiphrey

clipse said:


> I was on the fence as to whether or not I want an A2.........this thread did it for me. I'll have one on the way soon enough.
> 
> clipse



Yeah, me too.... I've been reading all kinds of glowing reports for a loooong time now, and the recent resurgence of these has pursuaded me at long last. You people are crazy. Now I have to figure out an explanation for why I actually needed another flashlight..... :laughing:


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## clipse

Now all I need is the glasses. 







enjoy,

clipse​


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## batman

Yours has a very dark HA finish cmopared to my two. Great purchase.


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## lightplay22

Nice! I saw one on display recently at gander mountain that was dark like yours and all the parts matched perfectly. Made me wonder if surefire made some special just for retail store displays?? My 2 A2's are much lighter and mismatched color among the parts but work very well for its intended purpose. That light of yours is almost too pretty to use! LOL. Enjoy it!


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## Lightedge

I went to Sportsmans Warehouse to get one of these as my ultimate general purpose. I have a Gladius for that purpose now which I really like but would like a simpler alternative.

I tested the white LED on display and the light would only sporadically go into 'LED' mode with the twisty or button. When I would get it into LED mode, it would flicker some. I tried the yellow LED display light and got the same problem. I tried the blue and it worked as expected.

I held off purchasing the light. I expect more for $195.

Anyone know if SF is having QC problems with A2's? I was stunned by the poor performance of these display models.


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## dyyys1

My A2 did a little of the flickering thing on LED mode when I first got it. It stopped after a day or two, and I think it was flickering because the bezel was not screwed on tight enough.


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## Size15's

Lightedge said:


> Anyone know if SF is having QC problems with A2's? I was stunned by the poor performance of these display models.



They could need replacement batteries (?)


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## cy

this old thread got me to take out my A2. been running 2x bare R123 with excellent results. fit is pretty tight, so protected cells will not fit in. that's for the protected cells I've tried anyways...

it's amazing how a simple thing like turning the bulb can make in performance of A2. substantially more output.


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## LawLight

What do you mean by turning the bulbs? As in not making proper contact, so turning would make better contact? Or as in cleaning the contact points with cleaner?

Kev


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## cy

turning bulb to align for best performance. 

trial & error..


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## oregonshooter

Is there a thread on maintaining the A2? Mine could use a tune up. 

CY,
I'll have to check into the bulb rotation thing, thanks.


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## LawLight

Ah. I understand now. Thank you. I'll give it a twist - see if I can improve performance.

Law


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## marxs

a quick tip for those rotating their bulb, if you want to make the output horizontal against the horizon, take a quick look at the pitch of the fillament. if its horizontal against the horizon are your beam will be horizontal, if vertical then youll most likely get a vertical beam. i just figured this out after having tried so many times to get it perfectly horizontal...if i knew this early on it would have taken me 1-2 tries to get it right.


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## dyyys1

oregonshooter said:


> Is there a thread on maintaining the A2? Mine could use a tune up.
> 
> CY,



This is a pretty good one, although not exhaustive.
http://candlepowerforums.com/vb/showthread.php?t=100819


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## oregonshooter

Thanks!


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## Lightedge

Maybe I need to go ahead pick up an A2. The fact that no one is bringing up QC issues to speak of is pretty compelling. 

I can't explain the performance of these 2 display models. Batteries on the displays I tested were very bright on high so I doubt it was a battery issue but maybe. Perhaps the bezels weren't on good but I didn't notice any gaps. Who knows? I felt like I needed to consult with the A2 meisters here before plunking down ~$200.


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## LawLight

I've had no QC issues with mine. They've functioned as advertised, even above and beyond, IMHO.

Law


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## dyyys1

I will admit that my A2 has periodically had problems with blinking (as described above) and with the incandescent suddenly losing brightness. However, I have always been able to remedy these things by tightening the bezel or cleaning the contacts in the tailcap. I think the design of the A2 has the potential to be cantankerous, but none of the problems are of any real significance and none are hard to fix. I would highly recommend that you buy this light. Nothing matches it's utility in a wide variety of situations, and despite the quirks described above the quality of the design and workmanship is superb.


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## LawLight

I agree with dyyys1. Periodic maintenance on your A2 keeps problems at bay. This is a complex and well built light that will give you years of trouble free ligth if properly kept up. Just clean the contacts every once in a while and keep the threads lubed.

Law


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## js

Lightedge,

Hard to say exactly what was up with those diplay models without a bit more info, BUT, I would put some money on the following scenario being responsible:

Idiotic, mini-mag loving, non-flashaholic shopper grabs A2 and tries to turn the head to turn it on or off or focus it, but instead just loosens it enough to make the LED ring have poor contact pressure with the top of the body tube. The incan LA would still be find because of the built in spring-prong type contact points which allow for a bit of play.

I suggest you consider going back to the store and try tightening down the head/bezel part of the light until it is firmly in place. Then test the LED function again. For myself, I can say that I have never had one single problem or even glitch with my A2, but I could probably create some problems by loosening the head or gunking up the tail cap internals.

Anyway, if you re-try the store demo models, let us know how they fare after the head tightening treatment.


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## g36pilot

Bring your own fresh batteries also.


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## wmirag

You guys got me... AGAIN.

I just ordered an A2 in white.

I couldn't resist after hearing all these great things.

W/


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## LawLight

Wmirag:

It is a purchase you will honestly be very glad you made. It will serve you well.

Law


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## lightsandknives

Like others, I too had to have an A2 after reading this thread. I must say, I was pleasantly surprised by the brightness of the LEDs. I was afraid they would just be too weak to be of much use but I think they would provide adequate illumination for a casual walk in the woods. They're certainly brighter than the secondary level of my EDC42 which is supposed to be 2.6 lumens I believe.

I just like the idea of having a regulated incan! I've been taking several lights with me on walks after dark this week and I really like having an incan to light up the area around me if need be. I have a few LEDs with decent throw but not like the incans, and I like the color of the incan in the woods.

My only concern is when I turn the switch slowly, the LEDs will come on and if I twist just a little farther, they will go out. A little more twist and they'll come back on and stay on. If I twist quickly, I don't notice it since I zoom right past the hesitation. This was the only light they had with the new body style and I tried it out in the store and noticed it there. It wasn't a deal breaker because I don't think it's a serious problem since everything else works just fine! I was just curious if anyone else has noticed this with their A2.

Great light and I'm looking forward to putting it through it's paces this weekend!


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## LawLight

you might try new batteries, and if that doesn't work, try lubing the threads of the tailcap.


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## Delvance

I've got a new style A2 and have not noticed that problem. Perhaps try cleaning the top of the body tube and the three little floating contacts inside the tailcap.


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## rgp4544

lightsandknives,

That is because of the thread design on the A2. If you are pressing in at all you can actually put the metal twisty portion of the tailcap in a position where you can use the metal twisty as a momentary on. Check to verify whether or not you're applying forward pressure when twisting the tailcap, if you are you will have a "momentary" twisty. If twisting while applying pressure toward the rear, that momentary flash should not happen.

Richard


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## Scott112

Well, after resisting for more than a year, I finally gave in - my first A2 arrived yesterday. After the 24 hours, my first impression is that this is my favorite light - by far. It's much better than I expected.

The LED's are better and brighter and more pleasant than I expected. Granted, they're not a flawless white flood, but they're more than adequate for navigation without blowing my night vision. The regulated incan is fantastic outdoors. Last night I watched a deer eating from my deer feeder - it was just a dull grey shape with reflecting eyes using the L2, but when I switched to the A2, I could see it's color and features clearly. But after using the L2 for the past year, it's the smaller size & weight of the A2 that I like most - a perfect EDC size.

My only complaint is that I deliberately bought the old style body with the flat sides because it looks better, but I wish I had just gone with the new style with rounded sides which is more comfortable. Maybe I need another one….


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## LawLight

Scott:

Oh yes, you definitely need another one. Keep the "squared" body as a collectors item and EDC the round one. Gives you a backup in case you lose the EDC too!

Law


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## greenLED

Couldn't remember if I had posted this here before or not, so here it goes (again?). I've been working on a comparison of all LED (plus some common white LED mods), with beamshots. I'm finally done! 

https://www.candlepowerforums.com/threads/119758


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## wmirag

I received my A2 yesterday and I *really* like it. I found some things regarding the LED mode that are not exactly as noted in this thread. They are all positive.

1. The three LEDs on my light have a blue tint but are not "angry blue" as they are on my late-model Arc AAA-P and various other small LED lights.

2. The LEDs on my light do not result in three hotspots. In fact there is one hot spot, somewhat circular. There are artifacts in white wall mode but not in real use indoors or outdoors.

3. The A2's LEDs *appear* dimmer than my late-model Arc AAA-P when shined outdoors on the ground in front of me. That was disappointing because I figured the A2 would be brighter than the Arc. BUT when I pointed the A2 at an actual object, the LEDs "threw" *at least* 50 feet such that I could see everything I needed to. Of course the Arc, while wonderful, doesn't throw 50 feet or anything close to that outdoors. The throw really surprised me because the up close behavior is so modest. Can anyone explain the phenomenon?


The incan was as as good as I expected it to be i.e. as described on this thread. The beam shape is very dependent on the rotation of the bulb inside the bezel. I think it's at its optimum when it produces an egg shape. If one of you experts could post a "correct" beam shape, that would help us mortals as a target for tweaking.

The fit an finish are Surefire perfect. And it feels great in the hand.

Thanks for parting me from my money AGAIN. I think I'm going to really love this light.

W.


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## marxs

glad you like your A2, I sure like mine a lot. regarding the tweaking of the bulb to get a "correct" beamshape, I dont think there is one. it would depend on how you hold the body of the light. personally i like my beam horizontal against the horizon, that way i get the hotspot on my normal vision. putting the beam in an egg-shape fashion lights up the top and bottom part of the hotspot which i dont find efficient...but to each his own.

mark


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## Blindasabat

wmirag said:


> ...BUT when I pointed the A2 at an actual object, the LEDs "threw" *at least* 50 feet such that I could see everything I needed to. Of course the Arc, while wonderful, doesn't throw 50 feet or anything close to that outdoors. The throw really surprised me because the up close behavior is so modest. Can anyone explain the phenomenon?


I think that comes down to the A2's lumens are higher, but the color alters your perception of throw on different colored objects. If you point an LED at grass at your feet, it looks pale and indistinct. If you point it at something further away with certain other and maybe (I'm by no means an expert here, just going off my own experiments) different colors, then it will light up those colors better. LEDs emit a far less broad spectrum of light and that narrow band changes from LED to LED.



wmirag said:


> The incan was as as good as I expected it to be i.e. as described on this thread. The beam shape is very dependent on the rotation of the bulb inside the bezel. I think it's at its optimum when it produces an egg shape. If one of you experts could post a "correct" beam shape, that would help us mortals as a target for tweaking.


I don't know if there is an established optimum, just try rotating the bulb until you get something you like. You may have to do some outdoor tests to see what gets you the most throw, but my testing gets better throw from the smallest spot.


wmirag said:


> The fit an finish are Surefire perfect. And it feels great in the hand.


It does feel great in the hand. 



wmirag said:


> Thanks for parting me from my money AGAIN. I think I'm going to really love this light.


As many do.


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## js

Wow. This thread just keeps on ticking! I'm very happy to be part of the effort to spread the word on the A2. It really can sort of slip by under the radar for many reasons, but for many people it is such a useful and pleasing light that it's just a shame to miss out on experiencing one. The A2 still deserves a prominent place in the consciousness of the flashaholic collective memory. It's still definitely one of the lights (amoung many) that should be considered and discussed (and praised).

OK. Let's see, as for beam shape and rotating the LA, that's a really interesting question! I had never considered it before, believe it or not. But now that I do, it occurs to me that if the filament is oriented in such a way that the more intense parts of the inward travelling fillament radiation pattern fall on the LED's, that it will distort the hotspot somewhat, possibly making it less oval (???). If my reasoning is correct, I would say that choosing the most intense OVAL hotspot would be the best for throw and total output both. But I could be talking out of my rear end here. Maybe I'll play with my own LA's orientation and see what I can find out (if anything). And perhaps Size15s or similar type CPFer will be able to provide the definitive answer. Interetsing . . . definitely interesting.


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## Size15's

Jim, I've not really been too bothered about the beam shapes of the A2's I have so I've no answers for you. Sorry


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## js

Yeah, me neither, but I thought maybe you might have known something . . . but no worries. And it wasn't so much for me as for wmirag who posted above.

So, wmirag, I'd say just play with the rotation and see what you find out. Then post back here so we can all benefit!


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## rgp4544

Mine have some significant beam differences depending on the orientation of the bulb.

I'm curious though does anyone know what would happen to an A2 if you accidentally put batteries in backward?

Richard


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## js

I really don't think reversing the batteries is a good idea. For all I know, it could damage the regulator. But I'm not sure. And the LED's certainly would NOT light, and for all I know, you might damage them as wel--but I don't think so. If anyone knows for sure, please chime in here.


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## rgp4544

JS,

Thank you for the input.

Fortunately I haven't made that mistake yet on any of the A2's I have, and hope to avoid it in the future, but I sure wish I knew whether it would do damage or if it just wouldn't turn on.

Richard


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## leukos

rgp4544 said:


> I'm curious though does anyone know what would happen to an A2 if you accidentally put batteries in backward?
> 
> Richard


 
Because of the diameter of the spring in the tailcap, I'm not even sure it would make contact (perhaps a built in safety feature).


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## Papacosmos

Hello, can anyone tell me how to replace a cracked glass window on my A2?


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## dyyys1

Welcome to CPF! You can probably contact Surefire and they will fix it for you. However, they would probably want you to send it to them and it may be several weeks or more before you get it back (I don't know this from experience, just from what I've heard). Surefire is great about fixing stuff, just not always fast. You might be able to convince them to just send you a new window or even a new head (although the latter is unlikely). Alternatively, you can try to fix the window yourself. However, you will have to find and buy a window with your own money. Also, you may have noticed that the bezel doesn't unscrew very easily. Apparently, SF puts some kind of sealant on the threads to keep them from unscrewing and/or leaking. Once you break this seal it's gone. You might be able to re-seal it yourself, but I don't know. I've heard that it is easier to unscrew with hot water, but you should probably search the forum (Google search engine at the top of the page) to find more specific instructions if you decide to try this. Good luck!


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## carrot

Surefire CS should fix that for you. Now would be a fantastic time to take advantage of the lifetime warranty. Give 'em a ring. You'll probably have to send in the entire A2, or at least the head.


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## oregonshooter

Yes, CALL THEM, do not bother with email as I found out recently, they are two completely different attitudes.


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## rgp4544

I finally whacked an A2 lamp, it was stuck in an SC3 spares carrier and I had to pull the lamp out to get to spare batteries. The lamp definitely intended to stay in the SC3 and I actually pulled off the rear portion of the lamp while trying to remove it.

I intend to perform some redneck engineering on the center of that SC3 carrier before putting another spare lamp in there. Apparently the hole for the lamp is tapered so this may require something like a rattail file.

Richard


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## afultz075

Just curious, but does the A2 overdrive it's LEDs? I noticed when white wall hunting that each LED has a bluish center. Isn't that a sign that an LED is being overdriven?


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## marxs

The blue tint of the A2 is normal as are common with the 5mm Nichias, these are what most CPF'rs term the "angry blue" color. AFAIK, the stock LEDs are indeed being overdriven if you use the incan. The angry blue color has nothing to do with the overdriving of the leds.

mark


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## js

There are three 5mm Nichias and SM resistors in parallel being direct driven by the two CR123A's in series with the 10 ohm resistor in the tail cap (when in LED only mode). In preparing for this review I did lots of technical stuff and took measurements and so on--all of which I left out of this thread. If it ever sees the light of day, it will be in part 2.

I don't have my notebook in front of me, but IIRC the three LED's draw about 110 mA of current on relatively fresh 123's. 110 mA/3 = 35 mA per Nichia. Is that overdriven? I don't think so, but I'm sure someone here will know.

In any case, as has been pointed out, the bluish artifacts are not an indication of the LED's being overdriven.


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## batman

I"ve done exactly the same thing to my A2 lamp assembly. The good news is, it's easy to fix, just snap the rear portion of the lamp assembly (kind of looks like a hat) back into place with the 4 little 'ol black snaps and you're set to go. 





rgp4544 said:


> I finally whacked an A2 lamp, it was stuck in an SC3 spares carrier and I had to pull the lamp out to get to spare batteries. The lamp definitely intended to stay in the SC3 and I actually pulled off the rear portion of the lamp while trying to remove it.
> 
> I intend to perform some redneck engineering on the center of that SC3 carrier before putting another spare lamp in there. Apparently the hole for the lamp is tapered so this may require something like a rattail file.
> 
> Richard


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## rgp4544

Batman,

I just tried putting this one back together after seeing your post, unfortunately when I compared it to a good MA02 lamp, it looks like I yanked a wire out of the white stuff along with the little hat shaped piece of metal...now I think I lost the wire.

Richard


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## batman

Hey Richard I'd go ahead and call SF and tell them the story...it shouldn't be that easy to break these lamp assemblies. If the operator is in a good mood they might just send you a free replacement. 
However, the customer service dept. told me once that using a screwdriver to pry the lamp out of the bezel is fine for those times when it refuses to fall out from gravity alone.




rgp4544 said:


> Batman,
> 
> I just tried putting this one back together after seeing your post, unfortunately when I compared it to a good MA02 lamp, it looks like I yanked a wire out of the white stuff along with the little hat shaped piece of metal...now I think I lost the wire.
> 
> Richard


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## marxs

a bit off topic, but i seem to have gotten the a2 cancer bug. last night i realized how useful the low beams are (been using it 90% of the time) and im loving it the more i use it. its not crazy bright like a luxeon, nor is it dim in any fashion, but for lack of a better term...it just seems like the "right" amount of light for almost any application i need both indoors and outdoors, im just loving this little bugger more and more. the incan still gives me the wow factor, nice bright and white everytime i use it. i know people say it grows old on you, but ive never experienced it till now.

now im having a hard time justifying why i should spend more $$$ on more lights 



mark


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## js

marxs,

I know EXACTLY what you're talking about. OK. So, for sure, I would NEVER sell my Arc LSH or my Arc AAA-LE, *but* I think if I only had a TigerLight and a SF A2, I would be quite capable of meeting all my illumination needs with style and grace.

The A2 low beam isn't as aesthetically pleasing as the L2 low beam, but it IS just the right amount of light in just the right beam profile for many many uses. The L2 low beam is too bright in some cases--at least to my eyes, anyway. While the L2 high beam doesn't throw as well as I sometimes need.

The A2 is just a really useful light, and the longer you own one, the more you realize that.


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## rgp4544

batman,

I hadn't thought of calling to see if that is covered with Surefire's warranty...I might try that.

Thank you,

Richard


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## JNewell

You will likely find their concept of "warranty" is very broad. It's true the up-front cost is relatively high, but these are quality lights made, sold and backed up by a quality company.


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## js

OK. This thread is getting well past the 200 post suggested limit, so I have started a part 2: The SF A2 - Part 2

Also, please note that I just edited the first post as I realized that in the discussion of exactly what is happening during the occurance of an "low incan" mode, I left out the fact that low batteries can cause this and not just extra resistance in the contacts. In fact, I see this every time my batteries get to the point where they will no longer support the incan. The incan doesn't just totally stop. Instead I push to activate it, and get a 1/3 or 1/4 power incan beam, and it has always been fixed by installing new batteries. And I left this possibility out of account in my original discussion. DUH! Too obvious or something. (Or stupidity. hehe)


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