The longest you have owned any gear?

This little oddity: a vintage 2-outlet isolation transformer manufactured by NCR. That stands for National Cash Register, folks. I acquired it in ’97 from a friend who had done a few mods to it. I gave him a pair of Linn Tukans and he gave me the NCR and 48-feet of van den Hul CS122 speaker cable. To this day I think I got the better part of that deal. The NCR isn’t stout enough to use with amps; just sources like CDPs’, tuners and turntables.

Years ago I owned a PS Audio Power Plant Premier re-generator. Initially I had all my components plugged into it but I decided to do an A/B test with my CDP plugged into the PPP and then the NCR. To my shock and dismay the CDP clearly sounded better with the ancient NCR. The PPP is long gone but I have a warm & fuzzy feeling that the NCR will be with me to the very end.

Bryston 4B-bought used 24 years ago. Now does the duty for my peripheral zone, 4B SST for my main speakers

My Hafler 9303 power amplifier which I bought in 1995 when I graduated from college. It was still in used until last month when I replaced it with the Job 225 power amplifier. 22 years in total with no problem. 

Simple.

Oldest (47 years) - Teac 4070 Auto-reversing Tape Deck.  Just had first tuneup.  Has always worked, and well.

Second Oldest (42 years) - Original Dual 701 Automatic Turntable.  Survivor of a shoot-out with my Linn SP12 / Syrinx arm combo.  Same mid-range, better bass, acceptable high-end.

Third Oldest (38 years) - ARC SP-6a.and Marcof PPA-2 headamp w/Moncrieff mod.  Recapped.  Noisy controls, but sounds sublime. Retired my 2004 Margules transistorized preamp. 

A Counterpoint SA 3.1 preamp I bought in 1986 and shelved in 2016. 

A pair of Sonus Faber Minuetto speakers I purchased in 1993 and sold in July of this year.