Heathkit S-99 distortion after operation
Earlier this year, I restored a badly rusted S-99, replacing all the capacitors, nearly all the resistors and the sockets on the power board. After members here helped me to catch a mistage on the bass control, I thought I had it all buttoned up, and I stored it away in a mostly clean and dry garage.
On returning to listen to it, I find that it has very mild distortion that gets worse after operating for an hour or two. I would describe the distortion as a burr in the sound.
Square wave testing on all the audio frequencies shows a clear trace, but this gets blurry at the edges as distortion sets in.
Because it is so awkward to trace a signal on the preamp board, I would be grateful for any thoughts on what might be causing this. Thank you.
David
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