Amplifier Longevity Question

Everyone has given good advice thus far, and I agree that with proper maintenance they should last for many years. You said that your wife was a classical musician. I I were you; I would explore a tube preamplifier. I think that you will both discover more realistic timbre and decay from instruments as well as better flow.

I have very successful experience with several vintage tube receivers, mono amps, preamps, some 1958, others 1964. Complex tape recorders from the 80’s. TT from the 80’s.

One example: McIntosh mx110z tube tuner/preamp, 1964. bought on eBay, tubes all tested good on my tube tester, listened, loved it’s sound for 2 years as received,

Then, sent it to Audio Classics for overhaul. Best thing they did was replace all the old rca corroded jacks with new gold plated jacks!

They replaced several capacitors and resistors because ’at this age, many of the components had drifted in value’.

Oh yeah, they aligned the FM tuner.

Great, but could I hear the difference? Nope, sounded great before and after, but those corroded jacks were problematic, new ones let me sleep better!

IOW, drifting out of value more than likely true, but audible, that’s hard to say.

Cleaning pots, switches, tightening tube sockets contacts with tube pins, testing tubes: I do that myself, but if not, the old stuff definitely benefits from having a shop do that.

I just checked the Universal Remote database, and the Magnum Dynalab code set is there. That means you can have an MX remote programmed to include your tuner’s operating controls, along with any TV & sound system you have. The MX-790 is $349.00 and a basic program is usually under $200.00.  Not worth it just for the tuner, but as a total solution maybe. Alternatively a cheap code programmable one from a blister pack might have it for $10.00. The GE or Phillips ones use the UEI database, which is vast. They are annoying to set up, but hey, they’re cheap.

Give your back a break and get a good Class D, Purifi Eigentakt or GAN FET amp, which will be as transparent and powerful as you need without the hernia.  NAD M23, or for more esoteric appeal, Orchard or Mytek. All under $4000.00, some a lot under. 

First, as the OP, let me say thanks to all who posted in response to this thread. Audiogon is a good place, with thoughtful and helpful members!

The consensus seems to be that my 20+ year old amps, which have been in daily use for about 14 years, and used only intermittently for about 7 years (2014-21), should be good for another few years at least, if properly serviced (and assuming parts are available).  I'm glad to learn this, because as I noted, I'm not itching to make changes just to make changes.  I've even learned to live without a remote for volume control, like the ancients.  It's not so bad!

Overall, I'm pleased with the sound of this system, which was much improved with the replacement of B&W 804S speakers by Sonus Faber Olympica III speakers last year.  (The B&Ws were good, and I had no complaints until they were destroyed; the SFs are in a different league.)  

Several members have suggested I reconsider my preamp situation, perhaps going to a tube preamp.  I appreciate the thoughts, and may do that at some point.  I also might get another SS preamp.  I have zero technical expertise, though, and I'm not handy, and don't like messing with equipment.  That was why, when I bought my MC402 many years ago, I didn't go with my other finalist, a VTL power amp.  The VTL sounded fantastic to me, placing opera singers in 3-dimensional space, as if they were on stage.  But the VTL ran hot, and seemed like it was going to be a demanding sports car, requiring attention. 

As for Class D and similar amps, I haven't heard any of the more recent products.  What I have heard, perhaps 8-10 years ago, left me un-wowed. But technology advances, and I keep an open mind.

OP,

Interesting hearing more about your system. I owned Olympica 3 speakers for many years. They were real game changers for me. To me, it also reinforces the potential for your system to be significantly improved with a tubed preamp… I am a big Audio Research fan and simply love their preamps… well, and phonostages… and amps. 
 

FYI, a classic pairing is Audio Research, Sonus Faber speakers and Transparent interconnects. I migrated in that direction for decades (not by knowing the association, but by careful component choices) and now… that is what I have. Best system, for me, that I have heard.