The longest you have owned any gear?

My Thorens TD-166 MKII turntable that I bought new in 1977 while in high school.  I had it refurbished in 2019.  I use it almost daily.

My Thorens TD166MkII, bought new in 1984 with a second arm wand. Now somewhat modified, but with original motor, arm, platter and plinth. It was a big purchase for me then, one year out of college, but I refused to re-buy my LPs in CD form and wanted a ’table that would last longer than my Technics belt drive TT. It certainly has lasted. It will probably outlive me.  Also, my Advent New Large Utility speakers, now in a secondary system.  My HS graduation present in 1978, refoamed in 2017(?) by Miilersound. Still sound pretty good.

Have had a Magnum Dynalab FT-101A FM tuner for 30 years and it has never failed once. Sent it back to MD for upgrading last year. Next oldest is a Bryston B60R Integrated Amp that has served me well for 20 years. It did require servicing at 19 years but, fortunately, it was within the 20-year warranty.

Spatial Coherence Preamplifier is definitely the oldest thing I own - a 1977 purchase.  Next up is a bunch of Amber 70 power amplifiers.   About the same time frame I purchased a pair of Shahinian Diapason speakers with four subwoofers. Pretty much everything else I own is much newer although my Conrad Johnson electronics have been around since 1997 or so.   

Still my TT. Purchased in 1983. Responded in 2017.