Capacitor Size

It actually sounds good, to be fair. But the fact is, I didn't have it in my possession w/ the original caps long enough to be able to notice a significant difference. Further, my speakers are very limited in the lower frequencies, so any improvement there is impossible to judge.

I actually don't have any complaints about the sound, save for the fact that a high frequency problem has arisen, which means the amp will need to be serviced (the right channel emits a lot of spitty hiss, for lack of a better way of putting it, while there is no source playing. I assume it's a capacitor problem of sorts).

Maybe when it goes in for service, I'll ask the tech to have a look-see for me.

Incidentally, despite the original tech informing me that the new caps are physically smaller, I only recently looked under the hood, as a result of the right channel, upper frequency issues (wanted to see if i could spot anything obvious). I was pretty surprised to see just how MUCH smaller the new caps are, however, which is what raised the question in my mind in the first place.

Are you asking about power supply aluminum electrolytic caps or film capacitors???

Your technician was on the level. Its a general rule of thumb that electrolytic capacitors (the kind found in power supplies) decrease in size in newer versions. It was that way in the 1970s and is still true today.

yep, Atmasphere is correct. The new caps for a given microfarad value and voltage are usuall considerably smaller than caps from 10 years ago let alone older caps out of 1970s or 1980s vintage gear. sounds like your repair guy is being honest with you.

The smaller value Electrolytic capacitors like 10KuF to 25kuF are smaller than caps from 20 to 30 years ago. The big 50000uF/125V,76000uF/100V,51000uF/160V caps cannot be made smaller than 3 inches in diameter and 5.9 inches long.
Even in the 1980s and 1990s these caps were same size as today.