Hey guys, I had a soultrane pcb (Fulltone Plimsoul) fabbed and I'm it sounds great except when the gain is maxed out and volume is high (others have reported this issue). I honestly don't mind too much because I would never want to max out the gain, but I have extra boards I would like to sell and was hoping there was a way I could eliminate the squeal/oscillation. Others have tried changing the volume pot to a 50K. Is this a good solution or are there better alternatives?
Okay, so I thought I had this thing fixed, but I am having two issues that may or may not be related. FYI the IC and transistors are unknown for this circuit. I used a TLC2272 and 2n5088 combo as Brian suggested. I have checked out multiple forums and there are lots of complaints about excessive gain and volume and also issues with a beeping noise when the gain is maxed out at high volume. I have both of these problems and I also hear a blubbering motorboat like sound when gain/volume are at max AND when pedal is plugged into amp but NOT my guitar. I did use a ground plane and a 9V plane on the PCB I had fabbed. Are the planes possibly the source of the blubbering sound (I'm ruling this out for beep since there are other reports of this)?
I tried different IC's and found that the beep and blubber went away with a TL062 when guitar was plugged in but the blubber sound is still present when the guitar is not plugged into the input. Unfortunately the pedal sounds like crap with a TL062 so that's not really an option and I'm hoping to eliminate both sounds whether or not a guitar is plugged into the input. I am quite certain I can swap the 100K gain pot with a 10K and eliminate both issues completely and still have a fair amount of gain. But I was just reaching out in case someone had a better suggestion to address these issues.
Try swapping the 100kA gain pot with 10kA. Folks were having the same problem with vero builds and this seems to fix it.