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Hey Tek...I wish I did have a scope, as this would not be so time consuming. Yes the amp is still usable, and while the hum is there while playing, it's not as noticable. The last time I used the amp I was running a distortion pedal with single coil guitars, so I didn't hear it. My son went to use the amp the next day and told me about the hum....any ideas on the above mentioned components mounted to the chassis?
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Useable & using it, huh? O.K... well then, it's probably just a weak filter cap alright.
These amps don't have 15 volt regulator tabs. Just series pwr resistors feeding zeners that clamp the voltage feed liness to the ICs to +/-15 volts.
I pulled out the official Peavey schematic page & flipped it over to view the component layout. Seems the filer caps on a 'Special 130' main P.C. board are just stnd axial-lead caps that lay down flat against the board. The + filter is nearer the board's edge (C55) & the negative filter cap (C56) is next to it, facing the other way.
Try CAREFULLY measuring for A.C. voltage across each capacitor (20 volt AC range is good) while it's running. If you get < a couple volts A.C. across one & much more across the other you've found the offender. These 4,700 uF @ 50 volt DC caps can be ordered from nearly any supply house. Mouser would be my choice though many surplusers have axial caps of this size.Comment
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Problem resolved
Hey folks, just wanted to let you all know that my amp is back in service. I replaced the main filter caps, and she is as quiet as a church mouse now. Thanks for the help.Comment
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