Amp longevity, if well taken care of --the risks of purchasing used equip.

My McIntosh power amps are 17 years old and sound the same as they did the day I first turned them on. I expect them to be the same in another 17 years. I have 3ea MC501’s and 1ea MC402 powering my 5.2 system. 

I've had a rotel 1090 for 20 years now still sounds great never a problem 

My GAS Ampzilla that I built from kit is still my working backup amp and is 51 years old. Still sounds great (after two rebuilds).

Many years ago I bought a pair of speakers at Stereo Exchange in Manhattan. Dave Wasserman, the owner, mentioned that the speakers sounded especially good with Conrad-Johnson amplification. I told him I was using a pair of McIntosh MC60s, and an Audio Research D51 amp as a backup. That drew a huge guffaw, and he said “I love a guy who’s got a backup amp. You clearly don’t need the CJ gear.”

I’ve had the Macs since 1979. They were manufactured in 1959 and 1960. I’ve had only two problems over the years, so I probably don’t need the backup, but I do sometimes swap in them D51 for a different flavor. The D51 probably dates to 1971 or’72, and I’ve had one issue with it. So yeah, older amps can be quite reliable. But I don’t know anything about Bel Canto. 

I purchased my Mac MC240 (circa 1967)

around 1995. Still going strong making wonderful music.