I have found that some pressings are far better than others on some of the records mentioned.
The first four Sabbath records on UK Vertigo Swirl are very impressive sounding (Vol 4 is the least good sounding in my estimation- not talking about the music, but the sonics).
Aqualung- agree it is basically a lousy recording. I do have the single sided Classic 45s on Clarity. My go-to, however, is a WLP Reprise, which is far easier to find and cheaper.
Zep- yeah, too bad, huh. I've got a lot of different pressings and the best ones one get you to subpar sound:
LZ 1 - CC Piros/Monarch circa '74
LZII - 'RL' or plum
LZ III- Classic or plum
LZ IV- Porky/Pecko Monarch (or plum).
On Machine Head, I have a UK purple label- need to see what it is- not a bad sounding record.
Layla pretty much sucks.
The first UK of Blind Faith improves what is an ugly recording of some great music.
And so on....
