I am using a Sansui AU-217 for an amp on my PC speakers. Sansui used a glue to hold board components in place prior to wave soldering. this glue over time usually eats through the component leads. You may want to check your unit and look for oxidized leads. Also bypass the power supply caps with film and foil units, as well as the interstage coupling caps. Amazing how nice these units can sound.
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