In this video I perform a detailed evaluation on a working but "multi-decade" old Onkyo M-504 stereo amplifier. The customer has requested a thorough health check of this amp and suggestions to bring up the overall reliability / performance of this amp considering it is a "daily driver".
Following the preliminary evaluation of the Sansui 9090DB, I've begun stitching together video footage of the partial restoration the above unit is undergoing. Hence, this is part one of what will be a small video series.