I just built this pedal. There are a few things I'd recommend.
1) Do the Boost mod with the two resistors. It's very noticable. Probably should be a DPDT stomp switch but where you going to put that on a 1290NS box?
2) Do the Bass Cut Mod. I call it the Humbucker / Single Coil switch...
3) Don't use the internal 10k trim pot. I used a regular 16mm A10K pot and wired it to the board where the trim pot went. Now I have and exteral Bias control. This works great. I can dial in the Bias depending on the guitar I'm using. This is indispensible as far as I'm concerned
4) I didn't do the Si/Ge toggle switch mod on this build but I will on the next. I used NTE123A Si trannies that measured ~145hfe. They sound great. I like them better than the Ge OC140 CV7112's that I had which where about ~170hfe.
5) This pedal doesn't like to be anywhere but first in line. It also doesn't like my Vibe no matter where I put it. I may try a cooler tranny in the <100hfe range and see what that does.
Here's a pic of the guts...
That's shrink tubing, not electical tape, on all the joints. I did that for strain relief on the wiring so it won't move at the joint and cause a solder failure. And "yup" that's a Mullard "Tropical Fish" cap on there and and Allen Bradley Carbon Comps in the tone section... at least what I think is the tone section... everywhere but the two 1M and the 4.7 LED resistor.
This is turning out to be my new favorite pedal. Easy to build, mod, and sounds great. My FLC is still my favorite. I just can't get over how good that FLC sounds... I don't miss my AM Clone Chorus one bit...
Now I'm off to the bench to start my Wah... anybody want a Mint Fulltone Clyde for $200?