Hi, So I purchased an AMPEG B2R bass head used and I had no problems with it for quite some time. After a while though it started occasionally dropping a lot of sound and going very distorted. Then I would turn it off and unplug a few cables and what not and it would magically come back to normal. This occurred numerous times. I tried different cables and guitars with no results. Eventually I figured it must be a bad solder joint inside. Took the cover off and removed the components. I saw nothing wrong with the joints and when I reassembled it, the amp constantly had the weak sound and distortion issue. I then proceeded to disassemble it and clean all of the ground locations. Reassembled to no avail. I'm starting to wonder if its the power supply or maybe a set of bad capacitors? These are really just shots in the dark but if anyone has some advice that might save me hours of testing and trial and error it would be much appreciated.