Hi, I just bought a used unit. 24V PSU (original) In a wooden box. It also has a CE mark. That probably dates it to after 1993. Im playing an Active YamahaTRB5 through it. No matter what I do. I cant get a clean sound through it at any meaningful signal level. My bass is active but not very hot output. The adjustment screw underneath cant do it. Even switching the effect off with the foot switch doesnt cure it. There is a background buzz. Im running into a mixer. The clip light never flashes so its not output level. Ive studied the Ed Friedland Youtube and I cant get clean effects when I copy his settings. I would say it was maladjusted but I cant see any tell-tail damage to the screw heads (its what we look for where I work). Looking at the schematic, (Sht 1) there is an input followed by an op amp (these don't usually degrade - only die.). The signal then goes to the bypass switch on page 3 or continues through caps to another opamp. Since the distortion happens whether its bypassed or not. The fault must be here - probably the caps. ...... Unless I'm wrong. EXH microbass synth 1996.pdf Is this common in older units. Any advice?