I suspect typically 35 to 50 years or more , based on my experience… not much. But we all know capacitor performance falls after some time… probably less than twenty years. Then there is better performance in new stuff. Typically even in amps ten years is enough to get a very important improvement… say compare same models. For forty years I had Pass amps of equivalent power and design… ten years is very important sound quality improvements.
Heat is major cause of component wear, manage heat and get longer life.
And then we have much faster evolution and innovation in certain audio categories. Take streaming for example, I consider these components consumables, certain components may be obsolete in matter of months.
Think about how many audio components are considered failures prior to parts failure. Many components may still operate yet would be considered failures as no market exists for resale. I bet most of us have some equipment sitting around unused and not really salable.
1965 Macintosh MR71.
Still have a couple original Mac labeled tubes. Over the years, a couple choice caps in areas were switched out. Just has upgraded output jacks and original tuning cable replaced and indicator bulbs replaced. It gets daily use, sometimes I've neglected to turn it off and find it's been on for days.
The plan is to keep it going for another 40, when I turn 100. The original Mac tubes will probably outlive me.
@tablejockey I’m sure my MR78 will still be working in 40 years too, I just wonder if there will be FM radio; my concern is that when I kick the bucket my kids will be thrilled at the first $100 that is offered to them for the tuner.
Capacitors die the quickest, start at 20 years. All failures are directly related to thermal cycling unless it’s a power surge problem. The 60’s through 80’s are not hard to service, even the IC versions. It’s when you get into the mid 90’s and later, servicing becomes a swap out board not component replacement procedure.
"I just wonder if there will be FM radio; my concern is that when I kick the bucket my kids will be thrilled at the first $100 that is offered to them for the tuner."
FM, like OTA TV will always be around. Listenable music is the challenge. PBS is the only listenable choices with Classical and Jazz. R&R radio is long gone, unless your area has a station trying to hang on.
Put specific instructions in your will -MR 78 gets sold to an audio enthusiast at current market value.
Electrolytic capacitors have shelf life, used or not. No doubt heat plays a role in their demise, but even sitting new on a shelf will eventually make a difference. It is the gel used inside of them that will eventually change with time. Just physics.
I had a PS Audio P500 which was still working, BUT some of the power caps were so dry they rattled. In this case, they weren't so old, but in heat environment that took their lives.