Converting Manual Rotating Knob to Remote Operation

Not exactly what you were asking, but you'll find some related information/ideas here.

Please ignore #2 - #5, they're a bunch of f***ing idiots _{they're well-meaning simpletons} they jus' joshin'. If you're serious about this - and you know a bit about electronics - and you have the manual skills required (or loadsa money) - ^{_{and you can take a bit of ribbing from the kind of loonies that inhabit this space}} - then tell us a bit more about your aspirations.

OH Yeah!f***ing idiots

You're just jealous because the cat and I have a symbiotic relationship that allows us to come up with these strokes of genius.

But seriously, I wouldn't try to convert a decent old amp to remote unless it has the circuitry waiting to be used (but not implemented) inside.
I would imagine modern amps with a remote are digitally controlled whereas an good old fashioned amp will be entirely analogue, (and vastly superior because of it)
I had written to this effect but didn't post it 'cos the boss walked in due to the pressures of work.

The work in seamlessly integrating digitally controlled pots etc would seem to be excessive compared to the cost of a new amp.

When I was a kid...I made a remote control for the light switch in the bedroom using fishing line, more sophisticated than string.
Del

If your old amplifier is setup with pre-amp out and pre-amp in, you might be able to find a remote-capable preamp.

Tom