Distortion when turning volume up

[evolve]

Has anyone ever experienced any severe distortion when turning the volume up? I'm trying to gain stage the volume on the SP505 with the input gain on my audio interface. To get any real good volumes I need to turn up the volume all the way on the audio interface. When I try turning up the volume on the SP it lets out alot of static and distortion. I took the back plate off the SP to see if I could possibly clean a connection on the volume knob but I didn't want to break apart the soldering work. Does anyone have a possible solution?

[evolve]

disregard, turned out to be a bad cable, changed cables and everything sounds good again