Preventive maintenance or wait till it breaks?

I'm a pretty much 'fix it till it breaks' kind of guy. 😉

I would wait. just wait till it actuallly quits working.

once a part fails its easier to discover. usually.

intermittent issues take forever to discover and determine. sometimes they get misdiagnosed and what is repaired may not fully be the issue making for a return to the shop shortly after getting it back because the next weakest link then fails or begins to show its face.

Caps are notorious for causing issues as they can and will work even though they are on their last legs. occasionally fialing and then seemingly rising from the dead to partially perform again. briefly. usually they are accompanied by noise in the signal, if not in the device itself.

tubes are similar IMO. I tend to keep a log of run time and so far have not gotten near the time to replace any.

as for age.... I'm amassing a slew of antiques simply because my disposable income got disposed of a while back.

everything still works just fine though so there is that, thank goodness.

my preamp is the most expensive piece I stilll have. it retailed for around $10K new. I got it via the 'gon for a tad less than half that price. replacing it will still be a costly endeavor I'm sure, but that bridge will get crossed when it can no longer be avoided. it is slotted to be integrated into a secondary rig. presently it sits statically on a multi level rack under a covering.

Device replacement costs vary wildly. depending.

I've only had authorized service centers repair a few items, mostly receivers.

I had a new sled installed in a Sony SCD XA 777es CDP by a local Sony service center.

speakers I've sent to their maker for refurbishing. thankfully they are in my state so it was less a big deal logistically.

as for general thoughts on possible service needs I do consider service and support with what ever I do buy long before the purchase.

it may not be the thing which sways my ultimate decision but I do feel service and support on most of what we consider in this past time a big part of the buying decision and it has paid off a few times so far that S&S was available from its maker when it was necessary.

but the aforementioned preamp tells a different story. sheer performance was why I bought it. no other reason. now if it fails I'll have to rely upon third party service and I'm not looking forward to that prospect at all!

good luck.

The main problem is following: you replace 20 years old capacitors that can work 20 years more to new ones that can work just for 3 years. Sometimes old parts had much better quality than same new parts.

I have my tape deck serviced every three years or so. Capacitors were replaced once, ten years ago, transport overhauled, other things done. I send it to Willy Hermann.
Aside from the deck I don't do anything, but I don't have particularly valuable equipment. I once talked to Redgum people, I have their 20 years old integrated, and they said leave it alone for at least next ten years. Fine, sounds good to me, it works like it should.

Keeping heat sinks and ventilation openings clean and clear will do more for your amplifier’s longevity than replacing capacitors.