Sofirn SC32 Emitter Swap (lime-green SST40 to a lovely 519A)

Flashlight Modding and DIY Parts
1

I picked up a Sofirn SC32 recently and while I was happy with the design of the light, the stock SST40 was terrible!

Since I didn’t find any tips on an emitter swap online, I felt it might be helpful to share my experiences so others will know what to expect.

This light comes with a 5000K SST40 under a unique Fresnel optic.

Not high-CRI, but I had hoped it was at least a decent neutral white.

It was not.

Maybe the beamshots are better…

Nope, not at all. Right against the wall, the beam offers a glimmer of hope that it might have a neutral-white hotspot with a greenish corona - not too terrible if you’re okay with CREE’s fried-egg pattern. But take one step back, and that hope is shattered into a million green pieces.

To its credit, the Fresnel optic does a good job of blending the corona in with the hotspot. Unfortunately, that makes everything green.

This emitter has to go, or I’ll never use this light.


First, to crack open the light! I ran it on turbo for a few minutes to weaken the glue, then attacked it with a strap wrench.
Take care you don’t accidentally tear out the charging port cover while doing this.

With the bezel off, you can see all the glue they used - but no Loctite, so this step should be feasible with just hand tools.


Inside the head, I was surprised by three wires. Looking at the white wire, it appears connected to the body by via a contact around the screw - likely to carry the e-switch signal. Interesting design! Also, because the optic sits on a lip above the MCPCB, the screws are essential to press the board into the body. Otherwise, it risks losing contact with the body and condemning the emitter to a fiery death.

(And I noticed a weird manufacturing quirk - they reversed the leads attached to the MCPCB, but I guess the LED is soldered backwards too because it still works.)

My approach to this problem was to find a 12MM 3535 board that could fit between the screws, since all the boards I had would required drilling through a trace to accommodate the screws.

For the MCPCB, I looked to Kaidomain: 12mm (D) 3535 LED Copper PCB (2 PCS).
For the LEDs, I ordered some 5000K 519A emitters from Convoy: NVSW519AT 519A R9080.

After reflowing the 519A onto the board and adding some thermal paste, everything ended up fitting together! Not without some modifications, though.

I rotated the board to avoid shorts with the screws, meaning I had to extend the positive lead with additional wire to reach its contact.
Additionally, I had to file down a corner of the MCPCB so it could be centered in the head without colliding with a screw.

But otherwise, this worked as well as I had hoped!

And there we go - that’s a nice 5000K light.

I didn’t exactly center it, but the optic should cover up that imperfection…

The beamshots look great now! The 519A SC32 looks much less green than the SST40, and even compared to the LH351D it appears slightly rosy.
With no green to mix into the beam, the Fresnel optic creates a blended pattern that is a lot more pleasing to look at.

Thank you for joining me on this journey! I hope it helps anyone else thinking of fixing the nightmarishly green beam of the SST40 SC32.

2

Great job. I’m about to swap emitter with SFT40 but still thinking about 519 upgrade eventually.

3

Did this mod tonight.

  • I didn’t have a 12mm star on-hand so instead I used a random 16mm copper star. I filed notches in it for the screws and ground down the mask around them, plus one more notch for the negative wire.
  • Initially I tried a 4000K 519a with dome-on. However, I wasn’t satisfied with the output so took the dome off.

Result:

  • Much more pleasing tint and CRI
  • Drastic drop in output. Dedoming costs lumens, the 519a is a lower output LED, and the 519a cannot run on a high-drain 18650 without the tint turning bluer and output dropping. Result is I have to switch to a higher resistance 18650 cell. At a guess the light’s peak output is maybe 1000 lumens now, compared to probably 2000 with the SST-40. Pretty drastic drop in output for the improved tint and CRI.

Other comments:

  • I quite like the Fresnel lens that comes with this light. I haven’t seen any other LED lights use a setup like this. There’s no reflector at all. Instead the lens sits above the LED and produces a beam pattern similar to an OP reflector, but using half the height a reflector would use. At a guess, this optic setup has a similar height to a Carclo triple TIR optic which only requires 7mm above the star.
4

Nice mod Serlite! Thanks for sharing your insights.

Any mod that changes the tint to be less green is worth it to me!

5

I generally am not as bothered by green as some, but damn that is green. That’s straight algae!

6

My sc32 arrived last week and didn’t come glued.

7

Lucky! I cracked the optic trying to get mine open