Ross Comp break up problem

[ragtime8922]

I have a wierd problem with my Ross Comp. When you turn the sustain knob past 1:00 it gives you a overdrive/break-up sound. However, when you stop turning the knob the break-up effect stops. It only happens while the knob is being turned. Weird! Any ideas/thoughts? BTW, I use 2SC1849 transistors.

[petemoore]

Aren't there a couple different type transistors in that? 3904's and 3906's IIRC. I had to watch the pinout, determining the PNP ones by the [slightly hard for me to see] little arrows that are pointing differently in the two transistor orientation designators on the schematic.
 Transistor data sheets should be used to determine transistor applications. Compare what you identified's data sheet with the schematic specified transistors data sheet.
 Cap orientation [polarized caps]
 Diodes polarity
 OA bias voltages
 There is a longer list of things to try in the debug page.

[Mark Hammer]

Clean the pot.  It seems to be behaving like something that can't make up its mind where it has been set to,