Boners.........................so many to choose from. So I'll go with the latest two.
BYOC Analog Delay. Customer build. I was METICULOUS! Did NOT fire up on the first go. List of problems:
1) LED & bypass not working
-solution- With the help of a wonderful mod, walked through a troubleshoot and found out I had a bad tranny in the Millenium Bypass portion of the circuit.
2) No effected signal out - after much reflowing and tracing and continuity checking, finally replaced a dodgy trimpot. I have been building for 2 years, and never had 2 bad components in one build.
3) When setting the trimpots and cleaning up the clock noise, switched from a 555 based sound generator I built (kinda hard to set repeats with a box that goes 'tic-tic-tic-tic'). And the signal is GONE. Whip out the DMM, trace the whole dang pedal, and a half hour later, give up and go to bed.
-solution- In the morning, realize I plugged my guitar into the 'Dry Out' jack. This won't work. LOL!
And lastly, picked up a populated ColorSound SupaSustain. Built on perf. Traced it out, added the offboard pots and jacks, breadboarded it - Success.
Boxed it up, plugged it in, created the most annoying high-pitched squeal ever to deafen a human ear. Glad I got child bearing out of the way, because I am surely sterile after that sonic assault.
--------------Solder bridge between Vol 1 & 2 on the perf. Blind builders should NEVER box a perf build without checking for strands of solder too small to see bridging traces. Never. I meant don't do it!