Is RIAA equalisation enough for Phono Stages?

Seems to me the original poster was not talking about historic recordings pre RIAA standardization, but that after the adoption of the RIAA curve some recording companies were stubborn or otherwise got creative with eq. Maybe someone can set the record straigth here, hell maybe even David12 himself if people let him!

I am only reporting the Jist of the HiFi+ article, whether the problem was non adoption of RIAA, or as Steph Gaynor suggests, other aspects of cutting and mastering, I am not sure. It certainly ties in with my experience of DGG, that I never really enjoyed them. Roy Gregory reports finally understanding why Karajan was considered a great conductor, with specific equalisation of his DGG pressings. I claim no great expertise or experience in using different equalisation circuits. I raised the subject, simply to find a general view of it's usefulness in considering a phono stage purchase

It appears that some definitive research is in order as to what different curves would be appropriate for the different eras of the different companies.

EMT had a phono stage at the last CES with many choices on equalization of records. One listen to it suggests that you need more than RIAA. It also works for 78s.

This site http://geocities.com/midimagic@sbcglobal.net/mixphono.htm has an expalnation of Pre RIAA equalization. If you click on the "Recording curves" and "Record label usages" links at the bottom of the page you will see the various Pre RIAA curves.

Since I have many pre 1955 LPs, I have researched Pre RIAA EQ fairly extensively. I have seen numerous mentions that some Record Labels, particularly European labels, did not switch to RIAA EQ when the standards were adopted in 1954. Some of the articles that I have read say that most, but not all Record Labels had adopted RIAA by the end of the '50s. Some labels, however, did not switch to RIAA until the early '60s (European Decca!). The Record Usage Label table at the above website shows a number of record labels that did not switch to RIAA until much later than 1954. Though that table is not complete. I have a 1960 mono Philips LP that has the treble rolled off at the Pre RIAA slope of 6dB.

As you can see from looking at the EQ tables at the above mentioned website, designing a phono stage that can properly EQ pre RIAA LPs is a complicated task. If you are only concerned about 33 1/3rd LPs, then you need four different setting for restoring the rumble shelf, you need five different settings for bass rolloff frequency, and you need seven different settings for the slope of the treble rolloff. To have this many settings and audiophile quality sound is not a trivial task and it does not come cheap. I have been working with one manufacturer in helping him determine the settings for the Pre RIAA phono stage that he is designing. We have had lengthy discussions regarding the need versus the cost and effort required to add each separate setting.

An audiophile quality phono stage that can handle any Pre RIAA 33 1/3rd LPs is not going to be cheap.