How can it be that some old recordings sound sublime?

Class A tube mastering amps, tube microphones, minimal miking and a real sound engineer with real ears doing the work.  Simple enough as opposed to most of the dreck of today.

Ahhhhhh. 

Thank you!!

Im thinking many great albums that should good could sound amazing if this is what came out of 1961.  

Yes real sound engineers but also I suppose real producers who let those engineers work. And good engineer knows how to choose equipment and use it. 

Class A tube mastering amps, tube microphones, minimal miking and a real sound engineer with real ears doing the work. Simple
enough as opposed to most of the dreck of today

THIS.....‼️

Celtic nailed it--no overdubs, heavy processing, etc.. But also minimal or judicious use of compression.  

A recording being mastered for home listening will not have the dynamic range compression of a recording that is anticipated for radio playback.  Heavy dynamic compression is used for radio playback because radio is often listened to in noisier environments--hence the need for "steady" volume levels.