Since I only had Linear 1M pots on hand I used a 100k resistor across the wiper/positive/left leg for the frequency pot, I changed out the 10k and 10n under that pot on the board for 47n and 47k to reduce the range, you can make it into a bass drum by making those 100n/100k, turned up the hiss by swapping the 100k in the bottom left of the board for a 180k, the other mods are listed in the BOM/Build guide for the decay change and the log response to the noise pot… I did a few other changes to the noise -> vco mixer section that make the noise a little more prominent but I’m not sure if it’s just my ears or what…
Honestly I don’t know that what I did to mine is anything groundbreaking, but the tweaking made it sound right with the other drum/percussion modules I have in my rack. The process of staying up till 3am desoldering/soldering new resistors/caps to see what changed, checking out the waveform & voltage changes with the oscilloscope, and really learning something about electronics, was what was really rewarding. You don’t generally get that kind of fun/flexibility with other DIY builders/kits, and Andrew encourages it in pretty much all of his build guides… It’s very unlikely you’ll blow anything up, and hey if you do it’s likely just a $0.50 CMOS or Opamp…