[Review, now with working images] Sofirn SP40 headlamp (right angled 18650/18350)

Did your WP review get taken down?

D’oh. Yeah, looks like WordPress suspended my blog and now all the images have gone here too. Hopefully I’ll get it back soon.

I was wondering where the pics were.

Thanks for the review. I was about doing another one, but I think there’s not much left to tell.

Just one thing: I got the NW model from Sofirn (colour temperature not specified) and was surprised to see a green beam. Last time I saw that was the light from Olights R50. I mean, that’s ok. Looks nice outside. But it’s far away from BBL. Am I the only one who got a SP40 with this extreme tint?

The Amazon listing didn’t say whether this was the NW one but mine is warmer than I expected, so I think it could be. It’s noticeably green by itself to me, even on a white wall. Comparing it to other lights though, it is slightly on the green side of the BBL, though not extreme at all. Is there a good way to measure this with a phone?

Always interesting to see people’s thoughts on lights.

The sooner the XPL versions are gone and LH351D are used instead, the better.

And a <1lm moonlight mode.

And stabilisation.

Regulation would be nice too, yep.

But for the price, it’s hard to ask for too much.

The images came back. Hopefully the captions make more sense now!

Just fyi, driver is removable with no damage. It's glued around the rim and at the top of the vertical PCB, it's soldered to the switch PCB. Key is to first de-solder the top, then de-solder the LED wires, then gently tap down on the top of the vertical PCB to break the glue seal.

Switch PCB showing soldered ends of the vertical PCB:

Used solder wick to remove the solder joints:

Solder removed, now there's nothing holding the switch PCB down:

Used a 20 mm FET+1 driver, so now the SP40 is running Anduril2 with a 351D 2700K

Impressive work and nice LED choice. I wish I had the skills to mod lights like this. Maybe I should start practicing.

Why do I always feel like this when Tom posts a mod:

You mean you unsoldered the switch board, then just happened to have a new driver that would fit the switch board having Anduril 2, and then put it all back together? Or did you just upload Anduril 2 to the existing driver?

Yea, sort of 1/2 the mod was shown . Didn't get a chance to upload the pics of the rest of the mod.

Think in this case, you are close to correct. I had a 20 mm driver sitting around already reflowed with the FET+1 parts, ATTiny85, etc. Then downloaded the latest Anduril2 I got, wired it up, pretty simple mod actually.

I get the bare (bare is better ) driver PCB's from OSHPark, reflow the parts myself. In this case, I lose the charging.

One more thing -- I reused the stock switch PCB, just ran 3 wires from the new driver up to the top of the light: ground, switch wire, and wire for the AUX LED's running through the 2 holes and soldered to the matching pads (grnd, switch, AUX LED's). The AUX LED wire also has a resistor on the driver to knock down the voltage/amps to drive the AUX LED's. Only the RED AUX LED's light up because of the lower Vf of RED.

I do this sort of stuff so many times over the years, forget sometimes mentioning the obvious things, least obvious to me

Thanks for the comments. The thing that is getting me is the right angle board needed to hold the switch PCB. Did you design in pads so you could solder the right angle board to the new driver? Guess that’s easy enough if you are making a whole new driver. Or is that not needed at all? Really nice work.

Ohh - no, the right angle board (i.e. vertical board) is not needed. The switch PCB sits on a shelf, then when the rubber cover is put on, and switch bezel screwed down, it's held tightly in place. I'm using the 2 holes in the switch PCB to pass the wires through.

Uploaded the pics of the full SP40 mod, posted in gchart's review thread here: https://budgetlightforum.com/t/-/56981/98

Probably still left out a couple things - should have shown the soldered in-place switch MCPCB... :FACEPALM:

Thanks Tom! Seeing full teardowns makes me a lot more confident when I eventually try to mod a light.

Thanks Tom. That’s an incredible mod!

I’m considering this headlamp and have a battery question. Will this light also take cr123 batteries, 1 or 2, depending on which tube you use?

The driver isn’t regulated, so the cell voltage will be the same voltage that goes over the LED.

According to this Sofirn SP40: Headlamp with some hidden features it will take a single CR123A.

It might depend on the LED though, as the lower voltage of a CR123A may not be over the forward voltage of some LEDs.

I wouldn’t recommend 2 cells on series unless a flashlight specifically recommends it.