I have an Ungula that sounds pretty good with the guitar signal going through, good volume and distortion and everything, but quickly starts to self-oscillate when not playing. Using an audio probe, a quiet pulsing tone enters the signal path after Q1, somewhere around the "FUZZ" pot, and gets worse from there. Many people are suggesting transistor bias resistors, but I'm not sure where to go with either the probe info or where to start with the resistor suggestion. Any ideas on what to check first?
Last edited: