When Was The Audio Golden Age?

“Golden Age” certainly refers to a time in the past.

I would agree that the time pre SS and pre digital would fit.

However, if it refers to the High End’s achievements in absolute SQ, Now is pretty “Golden”. For decades, I was a die hard tube guy. I don’t think that tech has really advanced much. But SS has. It took me years and decades to warm up to SS, but Now there are a number of SS designs that definitely bridged to gap of the tube sound and, IME, have eclipsed Tubes. And the best digital has done the same with analog. 
And, speaking of digital, one cannot discount the near endless selection and convenience. To many, that makes Now the Golden Age.

For playback equipment now is a great time. 
 

for recordings I think it was the 50s with tube electronics and no gazillion pot mixing boards (and no digital). 
 

The musicality and warmth and detail from many recordings form th 50s just isn’t present in most modern over processed recordings. 

I agree with @sudnh and others who have referenced the 50’s and early 60’s as the golden age of sound recording, especially in classical music. Tube equipment and mini miking led to the warmth and incredible sound staging that is only beginning to be matched digitally in the past few years.

esoteric = intended for a few… Now is golden…enjoy it.

But just in case…i run a ( heavily modified ) 1961 MC240 in one of my systems…

Right now. High resolution music unlimited for literally peanuts. Very reasonably priced DACs and amps and active speakers, delivered to your doorsteps AND you can return them for a full refund, no questions asked.

Seriously, could you get all that just 15 years ago?