Old SS amps

@dynacohum I have some Great American Sound (GAS) gear: two Sons of Ampzilla, a Grandson and a Thoebe preamp. One Son and the preamp need repair.

How long will a amplifier last if it's stored away in a box? Is there a shelf?

I have a Mark Levinson No.23 and a No.27.5 which I acquired used about twenty years ago. Although they have not in in use for several years now, I am confident that I can plug either one into my system and they will do just fine.

How long will a amplifier last if it's stored away in a box? Is there a shelf?

@emergingsoul 

The process by which electrolytic caps self-heal is suspended when not powered. Caps can become severely dried out as a result.

There is no hard expiration date, but any equipment that uses electrolytic caps (not just amps) and has been in storage for a long time should be brought back to life slowly and safely on a variac, as long as it has a linear power supply (SMPS-powered equipment is another story, but few audiophiles own any). The variac process allows caps to reform. Long-stored equipment should never be plugged straight into the wall.

A variac is a variable AC supply. It's quite inexpensive and well-worth buying if you plan on putting any long-stored gear back in service.

I have/use a Yamaha RX-Z9 bought new in 2003 now with over 35,000 hours that still functions like new.  Maybe the fan is a bit louder.