Amp showing its age?

Lots of words of wisdom here.

Well dine.

I have a Denon PMA-757 integrated amp from 1985 that's still going strong. I had it serviced a few years ago, cleaning, replacing a few bulbs but that's it. Sounds great. It's powering a pair of Canton Karat 200s from 1986. 

My guess would be one or all. Power switches build up carbon from arching and become resistive after decades.  Electrolytic power supply capacitors, final stage driver transistors,  new output transistors.

Clean it, get the bias adjusted, and measure the power caps. 

My amp is 50 years old, still 100% stock inside. 

@mswale  Too late, already sold and replaced. Oh, well. I was already considering an upgrade. Lucky you on a 50-year amp. What is it, Crown? Early ARC? An amp like that would be a conversation piece if you started a thread on the subject in this forum.