The longest you have owned any gear?

I'm definitely not going to win the "oldest in-use component" prize here lol. In my current main system: Tannoy Canterbury GR speakers, 5 years. Out of all the gear I still have that I might actually sincerely use again: my SOTA Star turntable (now upgraded to Nova V), 14 years. BUT I've at least been rocking Tannoys as my main speakers for 15 years; my love for them has been consistent and unwavering since my early speaker setup days :) And Koetsu isn't too far off that metric either; one of them has been my main source/cartridge for 11 year now. 

Luxman T2 tuner bought in 1972 still plays occasionally.

I still have my wonderful Epos M22's from 2005.  They have played great music and served me and my wife well.