I pulled out a copy of Dvorak's 4th (or 8th, depending on publisher) Sym in G on an old blue Angel label. Put it on and listened to the first side as I read the notes. As I read, I noticed that it was thin on bass and a bit flat sounding played with a Dynavector 10x5. As I kept reading, it stated that it was a mono recording from 1962, when most labels still had mono lathes. It had been misfiled in with my stereo lp's. I played the flip side on my mono rig with a Denon 102, and what a difference. Bass, depth, hall reverb all appeared.
I find quite few very nice mono lp's, and it's my experience that you really need a dedicated cartridge to get the most out of them.