Acoustic Research integrated amp,purchased new in 1973,paired it with AR 3a's which sounded great,now have in a den with 1980ish Ohm Walsh 2.This little system with a very old Onkyo CD player sounds incredible,friends are amazed by it,the AR amp was designed for 4 ohms which both the 3a and Walsh are.
Oldest piece of gear you own
I will start - Pass Aleph Ono, vintage about 1997 or so, followed closely by an LP12, ca 1998. Speakers and tuner both are from 2000. Newest gear is a cd spinner, Simaudio, ca 2011.