older LPs - different EQ?


After seeing 35,000+ LPs in one place on Sunday, including a wide variety of selections from the early years of recorded music, I suddenly remembered a foggy thing that I read a while back, and I want to confirm.

My impression is that pre-1958 or so (1955?) the record companies used a different equalization curve than the now-ubiquitous RIAA equalization. Is this true? If so, what sort of phono stages do equalization for these properly? Anything else to be aware of in this space?
blw
i think the curve on the lp(33.33rpms) has been the same since the beginning...i wouldn't worry about it.
There are some different eq. curves in the older records. Columbia, Decca/London, another one that I can't remember, and the current RIAA. And yes there are some phono stages that have selectable curves that are built-in. Don't ask me to name one, but I know they are out there, because I have read about them.
My Marantz 7T (as did the original tube 7) had three different EQ curves on it, one if I remember well was a Columbia curve and also a different curve for '78s.

Bob P.
I know of one phono preamp that has adjustable RIAA curves, it is the FM Acoustics Resolution Series 122. I had a chance to listen to it about 2 years ago and it was one of the best I have heard tube or ss. I am not sure if they currently have a US importer but if you have a large collection of older lps it would deserve a serious audition.