Looks about equivalent to what it was before. Meh, if I have a light as bright as before with more modes and no noticeable PWM I am still mostly happy.
I do not have good soldering skill, I wonder if I’m able to do this 
Yup it’s a really easy job, just find a tutorial online and you should be fine. The hardest bit is making the solder braid stick to the middle of the driver board.
should i get a beast driver too?
Err… duh! 
It’s up to you of course, but recommended!
-momentumexchange
Very hot to touch?
(i don’t hv the j12, but have the j18)
I presume if i change the driver for j18 from KD also will be very hot to touch as its 7 leds? cannot find infos on here.
@ ME; So the pcb just make 2 wire (red to red, blue to blue as in your photo), make the copper braid + solder , put it in & voila? (+ & - as well). Maybe i just get another j12? no lights caught my attention except for x100 but the size…
KD dont sell any drivers for tf-3t6? or i did not search enough? (i know there is that resistor mod)
Thanks.
Cop, any number of XM-Ls driven to 2.6-3amps will get very hot pretty quickly so yes, I’d assume the J18 would also heat up fast with the beast driver. In fact, at 5-6 minutes, only the head of the torch is hot to the touch, the rest is just warm so still holdable.
Simpler than that - literally take out the old driver, file down the new one and solder it in then add a copper braid contact - you only have to do the red-to-red etc procedure if you accidentally split the two circuits apart on the new driver whilst installing. It seems that models of the J12 differ slightly in the way the driver is held in, so that’s something to be aware of.
So for anyone who has installed this driver, did you use the potting/thermal material KD sends with it and if so, how? I didn’t and my light ramps down pretty quickly due to heat and seems to heat up slower than with the stock driver seemingly indicating there’s less power or worse thermal transfer. Just wondering what you guys all did so I can improve mine.
Can you make me one ?
Short update: Received it yesterday. It isn't direct replacement, as Keygos driver is 32mm diameter and much shorter. (Silly me.. Thinking that Keygos head construction would match TR-J12.. No way. Totally different.)
So.. Time for more serious modding.. I'll keep you updated.
Where to order the green glowing tail band? And any before & after shots? I mean anybody can edit shots to look good or better. Would love a before & after shots. Anybody with this mod can back this mod up? 2200 OTF to 4000 is very tempting. But i rather let people fiddle with theirs I kind like my PWM and stock modes.
Ok. Driver is now tightened between body tube and head, using a piece of body tube threads as retaining ring. This makes the tube too short for two cells, but extension piece + ~50mm dummy cell fixes that.
Not very elegant mod, but it works. Stock wiring in the head is quite thin, so I might want to change that to beefier one some day..
Here are the first results with the new driver:
You might remember that stock Keygos was slightly less bright than TR-J12 (I confirmed that today before modding: ceiling bounce was about 3% less)
Now it's significantly brighter: If TR-J12 is 2200lm OTF, this is ~3000lm.
As you can see in the graph, the modes are well spaced and low is low enough. In addition to that, there are no blinky modes and PWM is very fast (= I can't notice it even on lowest low). OTOH, the high PWM causes some whining noise, but that's not so bad.
TC currents with two Keygos 26650 cells were: 5.0A, 3.75A, 2.6A, 1.2A & 0.2A (about 100%, 75%, 50%, 25% & 5% - note the last ones: 25 & 5%, not 30& 10% as said in KD page)
All in all, I'm happy with this driver and will buy similar for my TR-J12 as well.
Edit: Build thread here.
i installed this today
cool stuff!
_ the_ It has to be said… your photo gallery is incredible! I just love how you use flashlights to get unique light painting effects in the dark
Thanks! Glad you like them. :)
Wish I had more time for photography nowadays..
can we have some updates on those graphs please the with some new torches skyray 9xml fandyfire trustfire 9x XMLs 
I tried this on my J12 but was not happy with the driver.
The beast driver ran at 56 watts to the emitters for only 20 seconds before stepping down to 50% (yes 50, not 75) for 5 seconds then it went to 5% where it would stay for 10 seconds and then give me 1 second of 50% before dropping back down to 5%.
I haven’t been stuck with a bad driver since 2005 so I was doing pretty good, mod purchase wise, until this turkey came along.
I’d return it if I hadn’t filed it down slightly to fit but it’s too late now.
I think I’ll wait until spring to purchase another beast driver for this thing. Maybe by then it will be a different “batch”.
Oooh... I think this is what I need for my kinda disappointing 5x Q4 drop-in. Anybody tried/compared this one to the other KD 26mm driver, the 3 mode one?
Thanx for posting this. I’ll be thinking twice from now on before deciding to join the bandwagon.
If i make this mod, can i use 3 x 26650 batterys? And how long runtime is with 100% power?