I have some Hi Fi vintage stuff including a mono only Heathkit preamp and power amp from early sixties. the preamp was desighned to hold a second preamp circuit board in the box for Stereo but this has just the one These are both working fine but are currently not used.
Also I have a Pioneer "steriophonic" Hi-Fi reciever SM-B201 with 19 tubes including 2 6BM8 pairs for finals. it sounds great. the plates (anodes) in the finals have a tendancy to glow red after about 20 minutes. I doubt this is a good thing. so I don't power it up often.

Just dumped my last Vintage piece Nad 7020 from active service. The amp power supply died (Blew fuses constantly) some time ago and was using it only as a tuner and Phono preamp until a few days ago when I replaced it and my old prologic stuff with a Yamaha HTR 5960
Bought the 7020 New as a teenager in the late 70's it was a great piece of gear.