I’m Going In.
Back at the end of the Cold War, when high technology usually referred to electronic hardware, I was all over, in, and out of this amp. Furthermore, with the analog measurement equipment available to me back then, we checked the specs of this Dynaco and every other piece of audio gear we could find.
But until recently, I hadn’t cracked the screws to this old amp in 25+ years. Once I was inside I could see the effect of the last 2 1/2 decades.
For example, below you’ll see the effects of slow-cooking a circuit board for 50 years.
The area under the 7199 tube is noticeably discolored from all the heat thrown off by the tube. This picture also shows that the amp was wired with solid wire. Looks like 18 gage. With today’s thinking, this would be an application that calls for stranded wire. Perhaps the Dynaco folks thought that solid wire was easier for the kit-builders.
There’s signs that the multi-cap needs replacement. Notice below the evidence that the cap has leaked. There’s evidence of corrosion from the capacitor tabs downward,. In the picture it is easy to see on the to the 6800 ohm resistor. I have yet to check this with a capacitance meter.