Longevity of ownership

I have 3 systems:  Music room, AV system, and office setup.  I have owned everytihing more than 10 years (bought new or used) except for a Marantz pre-pro in the AV system.

What I’ve had longest is probably my pair of Thiel CS3.6s, still sound great.

Got older stuff in storage.

I have a pair of IMF transmission line full range speakers.  Monitor MKIII’s III’s

and TLS-50’s.   All from 1974.  Purchased new.

In 1979 I bought a pair of Dahlquist DQ-10 speakers and a Carver amplifier and preamp. The DQ-10’s are and have been my only speakers to this day.
Still have the Carver gear too but it’s “in reserve” now.
Macintosh amp/preamp now delivering to the DQ-10’s. Still sound awesome.

I replaced all my gear about six years ago. But before that I owned and used an Audio Research preamp for twenty years, a Threshold S500 (Pass) amp for fifteen, A Pass x350 amp for fifteen years. At least one or two Audio Research phono stages for over ten years each. Non of this equipment ever required service. 

I have a Sanyo turntable I bought in 1979. Needs a new belt. At least.