Few months ago my son and I, we picked up an Optonica amplifier for his stereo system. Previously, he was using a not so vintage monster receiver from the early 2000s but he was always intrigued by the sound and looks of a vintage gear. The amplifier worked fine and didn’t even needed any pot cleaning. My son just repainted the top cover as it was showing age and had couple of rust spots here and there.
This past summer, when he was away, I have decided to recap the amplifier. I didn’t have a schematic or service manual so I had to go and write down all the capacitor values from the actual boards. I then went thru my stack of capacitors to pick ones that match. Rest was ordered from Mouser. Once the order was received, I spent next few evenings replacing every single capacitor in this amplifier. All with original values except I upped two of the big capacitors on the power supply board. Not that I think, the amplifier needed it but that’s what I had available. During testing after the recap, DBT didn’t light up and sound was playing so I call it a success. I was happy that I was back at the soldering station for a few evenings and my son is happy with his newly refurbished amplifier.