The longest you have owned any gear?

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.

A linn LP12 ; 37 years and still spinning....Ls3-5a for 23 years....