Morley Rock'n Verb oscillation

[foxfire]

i just got one of these and it's as good/bad as i thought it'd be. however there is a high pitched oscillation that becomes noticeable when the loudness pot gets to about 9 o'clock and seems to get louder as the pot is turned up. i haven't been able to find a schematic and will be more than happy to take pics but it may be a day or 2 before i can get them posted. at this point i just wanted to see if anybody has any experience with this pedal. there are 5 or 6 trimmers in this thing and all the markings on the chips are basically gone. there are also a ton of electro's in there, could be a bad cap...