Golden age of vinyl recordings?

For me, the golden age has a lot to do with the music as well as the technology and is in the post-psych era in the UK, say ’68-71 or a little later. Studios were still somewhat primitive, bands had to be capable of playing the songs ’live in the studio’ rather than depending on dubbing in better parts. (Yes, they could overdub early on, but it wasn’t as much of a crutch). I think by 1970 or so, US studios had 16-24 tracks. That alone wasn’t bad, but it did shift the focus to the engineer/producer as an auteur and in the process, a lot of the product were studio confabulations-- some sound great, but have less to do with the sound of the room and the energy that could be generated by musicians playing together at the same time.
Much also depends on the production choices.
Whether or not you like early Neil Young, for example, Harvest (particularly the early Lee Hulko-mastered copies if you can find an unmolested one), sound fabulous-- very much a ’live in the studio’ recording, though tracks were recorded in different places at different times. It has a very organic quality.
PS: I also like the music in this time window- very creative, went in a million directions, London and environs were an incubator at the time and a lot of the templates for a lot of different genres of popular music were formed in this period that I appreciate-- very heavy rock, psych folk, early prog rock, precursor bands to what eventually was labelled 'metal' (though no cookie monster vocals or shredding). I think the scene then shifted to the LA singer-songerwriter thing by the early '70s. A whole different kettle of fish. And there were some really over the top studios there that got refurbished for the new rock-pop era. 

@inna- Chris Blackwell’s Island Records, an independent label at that time, was eating every other label’s lunch- he had signed Stevie Winwood and Traffic, went on with Jethro Tull, Fairport Convention, the band Free, King Crimson, Nick Drake, John Martyn and a long list of other notable performers. Other imprints were formed to compete for the ’youth market’-- Deram (Decca), Vertigo Swirl (Philips), Charisma and Harvest (EMI) among others. They signed, recorded and released bands like Pink Floyd, a host of progressive bands that grew out of the Canterbury Scene, Sabbath and the later records of Roy Harper. Atlantic, which really didn’t have much of a presence there, grew from its signing of Zep. That label also had YES and a number of other prog, rock and other bands.
There were lot’s of obscurities too. Comus-First Utterance is probably one of the strangest records you will ever hear-- but became a cult favorite for the newly emerging psych folk scene. I could go on, but I think that gives you some context. One of the artists told me that the main reason they were all in London was that rents were cheap; their proximity made working and playing together a pretty natural outgrowth of what was happening in post-Swinging ’60s London. And of course there were studios, equipment vendors and clubs. Joe Boyd (who represented Fairport, Nick Drake and a number of others) opened a club called the UFO that was a scene for a while. The original house band was Pink Floyd. In short, there was a lot going on, different than the NY or later LA scenes.
PS: a lot of what I really like are the obscurities that fell threw the cracks, commercially. Though Sabbath and Gentle Giant were among the best known bands signed to Vertigo, there were some pretty amazing records that came out on that label in the period 1969-73, from bands that were never radio friendly, but had killer chops. Several worth mentioning are: Gracious!, Patto and Cressida.