Let us not forget that ALL recordings are PROCESSED and have some relationship to the actual "live" performance, but not all of it.
In the "old days," this processing took place on TUBE recording gear since that was all that was available. When more sophisticated recording equipment became available, many times it was solid-state based.
SO, any recording you are listening to has the "imprint," if you will, of the recording engineer, the producer, the band members or orchestra director, and possibly others (marketing) in its final form.
A simple example would be that in the 1960's, "pop" recordings were "mixed down" so that they "sounded good" on car radio speakers, which, in those days, were not exactly designed to reproduce accurate performances, but instead were going for a "sound" that would "sell." (Buddy Holly is credited for "producing" his own music because he did not believe that a record company producer could create the "sound" that he had in his head.)
This is not necessarily "good" or "bad" but it is anything but "accurate." About the best you can do for that is to get some master tapes, which, if modern, have been "mixed down" from 64-tracks (possibly) to 4 tracks to play on a home reel-to-reel deck. You might also want to play some direct-to-disc vinyl recordings like those made by Lincoln Mayorga et. al. in the 1970's. There are probably others out there as well, but this is a difficult and expensive process, so you don't get many and yes, even those are "processed" to some degree.
So, buy what SOUNDS GOOD to you IN YOUR ROOM and don't worry so much about the electronics. For ME, personally, ARC tube HW playing through properly set-up Magneplaner speakers is the closest to "accurate" when reproducing processed music. Everyone has their own idea of this, thus the myriad number of companies producing home audio gear.
Cheers!