Hi all, I'm trying to use my new oscilloscope to track down why my plexi build has weird, spitty, modulating overtones (see https://www.tdpri.com/threads/not-sure-if-my-plexi-build-has-problems.984480/ or ). How would you go about trying to track down the problem? I figured I could try to probe the circuit and listen for where I hear the overtones, then maybe try to probe that location with the oscilloscope to see if I see anything weird. How do you set an oscilloscope to be able to visualize electric guitar audio, without it looking chaotic? I also figure I might FFT it to see if anything weird shows up on the frequency spectrum. I also figured I might probe all locations where power is filtered, to see if I see anything abnormal about the DC, since this sounds maybe like crossover distortion. Any other ideas?