Modded an Amutorch AX4 quad to run a FET+1 Anduril driver. Fairly simple mod, stayed with the stock SST-20 4000K's - I thought they look relatively above avg for SST-20 4000K's, smooth tints in the beam, yes - slightly green at low modes, not as much as I've seen from other SST-20's though.
This quad reflector light with SST-20's has a tighter hot spot than triple or quad TIR optics, brighter,maybe wider spill.
AX4 on the right, AX3 on the left, AX2's in the middle. If you didn't know, I'm a fan of the Amutorch lights:

More complete view of my Amutorch collection:

AX4 tear down. Classic driver mounted switch:

Dry style thermal grease - needs to be replaced:

The driver cavity is extremely tight. This quad light is the same length as a FW3A so sacrifices are made. I used the hot air station to removed the ground brass ring off the stock driver. The driver board is CK's design from here: https://budgetlightforum.com/t/-/37376/6600, which turned out to be about perfect fit

Reflowed:


Had to move the switch to the very edge, resulting in the back feet not making contact to the pads. Patched in solder/jumper wire to bridge the gap. tested the switch, then epoxied the switch in place to give it back support, keep from breaking/bending as these switches tend to do:


Didn't end up working reliably. Somewhere between 5-10 clicks, it stops working, the let it cool, get another 5-10 clicks with stopping again. So, got bad solder joint on the patch work, and it's epoxy sealed up now :FACEPALM: (I'm using this moji a lot lately...). Used 36 AWG to patch the patch, taking advantage of the exposed metal tabs near the top of the switch:


All good now! Working well with Anduril, temp calib, voltage calib.
I replaced a low profile driver spring with a brass button, and added a 22 AWG bypass to the tail spring. New 22 AWG LED wires, that are pretty short.
The light does get red hot in a few secs, as expected.
Does about 3000 calibrated lumens at turn on (VTC5D cell), drops quick. I measured 20 kcd throw, taken at 5m. Stock I measured 2500 lumens, 17.5 kcd on the same cell. I'ts not much of a power increase, but getting Anduril on it was the main reason for the mod.