Rivera Fifty Five Twelve Troubleshooting and Repair Service
This amp came in with a couple ailments. Unwanted noise and a general "it doesn't sound right" are typical complaints but each repair is different.
Sometime in this amp's life a tube had shorted and damaged one of the sockets. This needed to be replaced. The second issue was a bad power supply smoothing cap for the 18VDC active effects loop. It should be noted they used 100uF/20V caps in 18V part of the circuit which can read as high as 19V. When a component is used at 90% of it's max rating it's lifespan is significantly reduced. These capacitors were replaced with 100uF 63V for a long service life.
I try to make these videos better each time but I think the most difficult part is to be thinking about filming what's interesting while trying to narrate and explain your process. Editing out all the cussing and looking for misplaced tools also takes a lot of time!
Thanks for watching.