Do you own gear from defunct brands?

Thorens is still in business.

@dill Thank you!

Absolutely:

• Dynaco amps
• B&K amp
• Lazarus preamp
• Sterling Acoustics speakers

I think it’s more of a question if the component was designed to be repairable. For instance, H.H. Scott, Dynaco, Heathkit, EPI, etc., all long gone but their designs  use parts that are still available and their equipment can be easily repaired.  However, for all the designs from still existing companies that use proprietary parts (any number of specialized integrated circuits) you’re likely SOL if it’s more than a couple years old.  I’m always wary of anything with a CPU governing its operation. Unfortunately, that seems to be the norm these days… For those items, best to have a bulletproof surge protector 😆!

Two Adcom amps, GFA -585LE (2 channel) & GFA 5503 (3 channel) powering my home theatre -- Both have been serviced.  An Adcom GFS-4 speaker selector for passing the stereo signals to the backyard and garage through old Monster Speaker cables routed underground.  My second stereo system has a pioneer turntable, & Polk Audio SDA-2 speakers - they have a cable that runs between them that manages the phasing and stereo separation.  However, I never use this second system anymore. 

Red Dragon Audio m500 amps,and Monarchy Audio SM70 mkII amps.