As a HiFi collector and restorer, I don't have a lot of interest in 70s gear. The US Made 50-60s tube stereo gear by Marantz, McIntosh, Fisher, and Dynaco is my jam.
I'm guessing late 50s onwards, as stereo was introduced, what, 1958?
I'm a fan of the quad stuff from that era, ESL57s and Quad IIs as well as Tannoy speakers. I imagine you're more US centric in your appreciation, but it was a wonderful period of innovation in music reproduction when individuals with a vision could shape how music was appreciated.
My earliest piece is an early Marantz 7 from 1958. I don't get into mono era or cinema gear too much. I'd definitely be into Tannoys if I could find a pair of reds for a reasonable price. The only truly vintage speakers I have are Altecs.
I'm a fan of the quad stuff from that era, ESL57s and Quad IIs as well as Tannoy speakers. I imagine you're more US centric in your appreciation, but it was a wonderful period of innovation in music reproduction when individuals with a vision could shape how music was appreciated.