Yeah, that’s about right. it’s in the ballpark of the 7x and 9x XM-L lights. Mostly due to the driver. I guess they do not want to spend a few bucks to put a beefier driver in there. On the plus side, run time will be great in 4x26650 mode. 
thanks for the review. i love these high multi lights, i own the ak47 modded by richie that does 6000 lumens at around 90 watts.
let us know when you figure out a way to modd this bad boy.
So which multi emitter light do u think is the brightest as of today? Sub $100 that is. 
should I just be content with my King?
I don’t have a 12x but I have a 9x a 6x a 5x I had a 7x. Of them the only one that I think really is worth the extra money is the 9x. It’s a 9xT6 trustfire and with king kongs it seriously rocks and it’s no slouch with unprotected 18650’s either. I modded one by de-doming 5 of the emitters and putting in heavy wire and copper on the springs. I just sold it but man was it a nice light. Nice tint with the de-domed and extra throw and with the heavy wire and copper on the springs it had as many lumens as it did stock. I have another one that it now waiting to be modded. I thought about putting in an even more powerful driver but I just don’t think it will be worth it. On high it’s already getting hot fast enough.
Thanks 18. I was eyeing the ebay auctions on those but they have stopped all auctions now.
And sorry for the otp relic. 0:)
Overall, the SRK is tough to beat. It’s compact, most put out 2000 lumens stock, and uses four batteries which gives a decent run time.
In fact, when comparing to long plunger lights like this, it is not really in the same class.
Now, if you just do not care about the length or format this one offers a lot of potential. Unfortunately it is untapped in stock form. It will give about 50-60% more light than a stock SRK. That will be noticeable, but not a slam-dunk “wow that is so much brighter” kind of increase.
Figure out a mod for this to get closer to it’s full potential? Now we’re talking 
I have an idea or two for this, I just need time to try some things, probably after the DIY build is done.
I added some more side-by-side shots, they are in the first comment
A little something to help gauge the size of the AK-90
Nice work, Relic! I love that first pic of the light.
I'm shocked at the kcd this puts outconsidering the tiny reflectors. Modded for higher output this would be a real knockout!
Thanks JM, I was pleasantly surprised by the throw. I expects 25k, 30kcd tops. After modding this might hit 60-70kcd, which would be quite the throw for this class of light. I wonder what 12 dedomed XM-Ls would do for throw?
Simply replace all the XM-L with XM-L2 U2 and you will easily get over 4000 lumens… wait, that would be a whopping $80 mod!!
I thought of putting them all on direct-bonded copper stars, but the thermal test shows not much thermal sag in the first thirty seconds. I may skip that and save myself $30-$40.
Although, each emitter isn’t driven very hard right now. Once I bump it up things might change.
Any temperature reading of the head after a long run on high? How would you compare it to this one by the looks?
this one uses 3 batteries with no extension tube though, and 5 bucks more than AK-90. Have you look up to the specs of the fets. Would it be possible to beef it up by changing the sensing resistors?
Relic, can you take a photo of the IC which is right under the coil edge, the one with 10 pins?
Thanks for the review.
Nice driver.
Has the driver a under voltage protection? That is a thing I miss in these multi emmitter lights.
How is the tailcapcurrent with 4 cells compared to 3 cells?
When will you mod the resistors?
Very nice review!
Thanks for sharing!
I have not done a thermal test on this one yet. I did notice that it warms up fairly quick. The head is two pieces, and the emitters are mounted on the front piece. This means that there is an interface between the main heatsink and the emitters, which is not ideal. I added some thermal compound to the threads there and it seemed to help even out the temperature difference quite a bit. I’ll do a thermal test at some point.
The TR-J20 looks to have MUCH more heatsink surface area, and possibly more mass too. If that one had been available at the time of my AK-90, I would have got the TR-J20 instead.
The MOSFETs and diodes have no markings that I can see.
Resistor mod is definitely doable for more drive. How far it can go is unknown. Hopefully a lot J)
The next time I have it open, I grab some more shots of the driver. I recall all chips have no markings, so I doubt it will be identifiable.
I’ll check the low voltage battery protection and update the review.
Output on three or four cells is virtually identical, and tailcap current is altered as expected (lower on four cells). I measure it the next time I work with the light.
It will be a while before I get to mod this one.
Excellent review! Thanks for the data on lumen comparison.
I think if you mod it to take more current, it would drain batteries quickly.
Hey Relic,
This is a smashing review, very comprehensive.
Have you had a chance to play with the drive current on this yet? If so how much are you cutting the resistance by to see any good gains?
Dear god, how have I missed this. Have you tried playing baseball with this?
Nice pics by the way!