How to find the good CD recordings?

And then there's the issue of reversed channels on LZ releases. On Steve Hoffman there's a very long discussion about the matrix numbers and which issues have the correct L,R channels.

And then there's the issue of reversed channels on LZ releases. On Steve Hoffman there's a very long discussion about the matrix numbers and which issues have the correct L,R channels.

Speaking of which, one wonders what role, if any, Polarity plays in the differences among CDs.

geoff, I’ll bet phase was not a major consideration for recordings of that era.
As to polarity, there would be no consistancy, don’t you think?
I should invert polarity on the flat sounding CDs.

If the various Zeppelin masters for worldwide distribution had inconsistent channel assignments, how many other mistakes were there?

@n80A small contribution fro me. I started using Tidal two years ago and have since then put huge amounts of good music and also recordings to my playlists. Thought I had it all but no no no... The recommendation for a simle Node 2 or maybe just a Sonos Connect os similar is a very good advice. You might be able to get a little better sound but also if the quality isn't good enough from the beginning its not worth it to search for better material or buy more expensive equipment. The fine with digital is that you start from a very high level compared to before (when I was young). The negative is you get a resolution that is not very friendly to bad recordings (and most are).
Since you like good old rock I would suggest you to look for recordings made 1965 - 1975. Preferably UK artists recorded in the UK. The Who live at Leeds is fantastic. The last issue of Cat Stevens Tillerman might be the most dynamic of all time. It's a little scary to listen to :-) The Doobie Brothers always top notch. Takin' it to the streets the most perfect recording i know of. You can't play that loud enough (on my ATC 150 ASL). There's lot to discover. On these recordings it feels that the technicians didn't interfere at all (or didn't know how!), they just put the music through. Nowadays, I would say you find the best sound in the Americana and Alt-country scenes. But if you are playing LZ and feel the music is flat then I must advice you to change some equipment of yours (speakers). The last issues of LZ I - III are very dynamic. A little overemphasized around 2-4 khz which could bring you some fatigue if you're listening loud, but you can feel the kick!! I also would like to thank the person that gave us Black Cat Bones - like finding a new Free record!