Is it worth replacing an old amp?

I still have my original Yamaha HT amp from way back (and matching cassette player) and they still work and sound reasonable. I’ve acquired and passed on a fair number of HiFi and HT amplifiers, with a good number number of them Japanese flagship models. The beauty of these are they sound great (most of these would be in the top 80% sound wise) and second hand are great value.

My choice would be one of these.

Cheers AG 🇦🇺

I can just say that I changed from a cheap and old amp to a similar priced but new amp and the sound improved a bit. Then I changed to a much more expensive amp (also pretty new) and the sq improvement was huge, even with my old speakers. So it can make a big difference. I bought everything used and gambled but it payed off.

My experience is old can be just as good as new. I have two modern albeit Chinese tube amps, one of the Chinese amps is just OK, the other one is poor, experimenting on that one. I also have a 1961 Frank pram 30 integrated, I wouldn’t swap that for anything, it just sounds right in my setup. I have another 1960s integrated tube amp which again is just OK. To my mind there are too many variables to just compare old v new. As has been mentioned, try and get some home demos, what sounds good in the store, may not when in your home.

Simple answer.   Audition in your system a 'better amp' you may wish to purchase.  Any dealer worth his salt will allow you to do that.
If he doesn't, walk away.

If you think the sound quality is better enough to buy it, then buy it.
From the dealer.  Don't be a cheapskate and buy the amp cheaper on the net.

While you are trying out amps please consider Tubes.