The term Golden Age has traditionally referred to the 1050’s and 60’s, when the KLH 9, Quad ESL, Klipschorn, Bozak, and Hartley loudspeakers were state-of-the-art (along with the Hartley 18" subwoofer)---with the new AR-3 nipping at their heels, powered by either Marantz or McIntosh tube electronics, and a Thorens TD-124 or Garrard 301/401 turntable fitted with an SME 3009 arm and a range of cartridges. These were all products of the WWII generation of hi-fi engineers, who got to work after returning home from the war.
The next era began at the dawn of the 1970’s, with the appearance of Bill Johnson (Audio Research Corp.), Jim Winey (Magnepan), and countless others whose new products replaced those listed above. But those 50’s/60’s products held their value, and are now of course considered classics, in general more so than those of the 70’s.
Then there are the recordings and resulting LP’s, primarily the RCA Living Stereo and Mercury Living Presence. They were brought to the attention of 70’s-era audiophiles by Harry Pearson and his colleagues in The Absolute Sound Magazine, and thereafter rose dramatically in value.