The longest you have owned any gear?

I have a BT-1 preamp, EQ-1 RIAA equalizer, and 50 watt AMP-1 still in use from 1974. All built by the Quintessence Group from Sacramento.  I switch the preamp out with a BT-2 from Audionics of Oregon circa 1980, still sweet!  The EQ is especially useful as it was designed around the inflection points on the RIAA record curve.  They  are in use in my office system, main system is newer stuff.

Limiting this to items that are "team 1 starters":
Rogue Hera preamplifier (now at Hera II status) - almost 9 years now, which seems like an eternity here; I’ve only been seriously at the 2ch game for about 12 years. Next closest would be a Koetsu Onyx at 6 years, which I’ve had recently rebuilt (though technically this now sits behind my new Coralstone).

I’ve tried to upgrade away from the Hera twice now -- both times to more expensive and highly review/regarded tube units from more prestigious hifi companies ($10K and $14K list prices) -- and both times I ended up going back to the Hera as my preference (though it’s not without flaws). The Hera was my first true "high-end" 2ch component, and perhaps part of my preference is that its sound truly has become my reference over the years. Maybe I’ll try to upgrade from it again in a couple years, but it’s been a real warrior for me!

Longest I've owned from the start- Technics SL 23 belt drive (still works for my daughter) I bought used in college in mid 70's.
Longest period is Eico tube gear my Dad built at the kitchen table in the 50's when I was a kid- He put speakers in the wall of our living room- no Sheetrock then- plaster & lath construction- came to me when he passed- still works we still enjoy it.

Thorens TD 125 with SME tone arm...46 years!