Thanks! It’s on whenever the flashlight is off.
Not today, but I replaced the leds for luxeon v2 4000k and added an orange turboglow. It matches the button color.
The photo shows an exposed turboglow after a few seconds on high…
CRX CuTi HachiRingu Osram KW CSLPM1.TG 5400K - Convay·MK - 18350 - Rv Clicky Tail Sw - 1080lm.
Skilhunt H03 ended up warm white and high cri amid a bout of insomnia. 
I’m in aww. So many questions. 5400k? Where did you source that cct?
Kaidomain.
Hurray! I’ve finally built a firmware testing light where I can flash firmware for my drivers with a USB cable. I needed a small light to carry, USB port, usable on a bike, dual switch and lighted E-switch. The S42 fits all that except dual switch but fortunately the S41 tailswitch works fine. I’ve had a previous attempt at making a driver for this light but screwed up the USB port part of the driver. Now I got it (almost) right. Had to file down some internals in the host to fit the wires without squishing them.
Custom driver with holes for the original driver “poles”:
Driver assembled with a custom slave board with micro USB connector and charger chip (MCP73831). Really finicky to put together because the wires I used where too fat:
The flashing kit. The photo was taken while I flashed a light by USB cable for the first time ever 
So here it is, my dual switch EDC firmware tester. The first light I’ve built in ages. I burned up the red LED on the switch but that doesn’t matter because I made a mistake in the driver design and only have one channel for a switch LED. At least the green one is working
The only thing I don’t like about this light is the beam profile. I’m in no way a beam snob but this thing is horrendous! 
I know carclo quad optics don’t fit, is there any other option that does?
That’s really cool MikeC! That takes exposed pads to the next level.
I’ve always wondered why we haven’t implemented something like this. Nextorch had a GUI-USB interface to customize the UI back in 2010-2011.
Indeed.
If it’s like S41 then carclo triple with additional oring should fit fine.
Great idea with USB programmable light!
Thanks for the comments all!
I’ve wanted to do this for a very long time but it only became practical after converting to the 1-series. Thanks for paving the way!
I didn’t think about that, nice suggestion. I’d prefer only replacing the optics because the current quad MCPCB is fitted with two screws, which is something I like, but if I bum out on replacement optics I have something to try. I have a spare S42 laying around somewhere, I can at least check the fit before taking this one apart again.
Amazing what you’re able to accomplish, Mike and CRX.
Petl MYO XP - ad. 2005 - led, optics, cable, headband replacement.
Luxeon III -> Cree XP-G3
I swapped out the single Nichia 219C 4000K LED in my Convoy S2 to a triple Nichia 219B 4500K. The 219C was not a good choice for me in the S2. It had good throw, but I didn’t use it much since I have a triple JAXMAN E2L with the same LEDs. My 17 year old daughter wanted her own flashlight and she liked the tint of the 219C vs my other flashlights, so that was the perfect opportunity to modify the S2. We’ll be putting the LED into her purple S2+ host, along with a protected Samsung INR18650-35E battery.
I shaved the 219B LEDs using a razor blade and a washer. I wasn’t planning on doing that, but when I reflowed the LEDs, 1 of the domes got damaged. It actually worked out for the better since I now have a little more throw through the 10511 Carclo lens. I really like the tint and the S2 will certainly now get a lot more use!
Looks like a great light, NF. Triple 219B 4500K, MtnE driver, illuminated tailcap… 
I really need to try some 4500K emitters soon. 5000K has been my go-to but sometimes it’s just too cool. I usually find that 4000K is a touch too warm. Goldilocks complex I guess.
Thanks gchart! I really like 4500K, but I think I still prefer 4000K overall.
How hard was it? I have a Skilhunt H03 FC that I really like, with neutral white, but would like it to be warmer. I have some Nichia 219B coming.
Since I couldn’t pull the tube and driver (mine’s epoxied?) I had quite a dificult time manuvering the noctigon mcpcb in through the bezel. With the short, unruly, wires tucked one way or another the mcpcb’s reliefs were barely enough to rotate it in. I had planned on needing to remove some material from the mcpcb but that wasn’t required It is possible though tight to fit and I had no issues with centering after ensuring my mcpcb was properly seated.
only thing I would do different next time would be to use a proper torx driver