RIAA or not.. the LP/78 Equalization Conundrum

From another thread...

So, I'll start off posting a link from Graham Slee's preamp site. This is apparently quite a nice phono stage.

http://www.phonostagepreamp.com/78rpm-riaa-equalization.htm


I've found more, some more technical but Graham's is a good summary.

 

The EQ curves are close enough to RIAA that anything beyond minor adjustments via tone controls can derail enjoyment of the music.

 

Thank you, Mike.

From Wikipedia

 

I almost agree with you. But it is interesting as a knowledge and might give us another perspective for vinyl playback.

 

This post saved me several hundred dollars chasing down custom EQ hardware and hours trying to do it in software. The pre-RIAA 78s I've been needle dropping and playing sound fine with a little knob-twiddling on my Marantz.

 

It is a point that many stereo vinyl were cut using different EQ curves.

 

I've always played everything standard RIAA, no tone controls. However, I have had friends who know their stuff be impressed by correct eq. of the type on the Slee preamps.

Not all of us have the tone controls, and even then they really don't offer the correction these curves do.

 

So I just got a Rek-O-Kut Equalizer II to use with my growing 78 collection, and the manual that comes with it suggested trying it with older lp's, and even reissue albums that were mastered from old 78's. This is all new to me. Fun to try different equalization curves for these older records. Really does add something positive to the mix. I assume a lot of folks here who have large 78 collections know about using equalization to dial in correct curves, but according to this article equalization standardization didn't happen until 1958 and wasn't universally accepted until 1975, leaving a lot of possibility to dial in a more appropriate curve than the now standard RIAA. I'd be interested in hearing from others who use either this, or other equalizers, to dial in appropriate recording curves for their collection. With the accompanying charts that come with this article it's about easy as could be.

http://midimagic.sgc-hosting.com/mixphono.htm

http://midimagic.sgc-hosting.com/mixcurve.htm

 

Actually, it was 1954 that RIAA became the standard, according to a book I have that was published in 1956.

 

Ah, ok. Thanks. I guess the bigger issue is that it was years until it really became "standard", thus making finding the right curves another little thing that one can do to improve their vinyl playback, even if the difference is negligible at best.

 

Howard Tremaine's classic book Audio Cyclopedia goes into these EQ curves in great details, and also provides info on why they were developed over time. Sadly, a lot of this stuff is becoming lost in the mists of time.

With modern records (post-1954), I think having a good test LP is absolutely mandatory, because at least then you can see when something is drastically wrong -- like one channel is down 1dB, or there's a steep roll-off starting at 12kHz or something. Without the test LP, all you can do is make educated guesses (at best), particularly when it comes to alignment and checking individual channels.

 

I actually built a custom mono phono preamp, specifically to replicate all of the EQ standards for 78s. I used it for a while, decided it was a PITA, and switched back to my budget Audio Technica phono stage (which sounds better anyway).

78s are not a highly-evolved, audiophile format - never were. It's too tempting to overthink this stuff. Just enjoy the records, and occasionally adjust tone to taste.

Works for me.

 

Agree on everything. The nice thing about the Equalizer II is that it's transparent, and it takes seconds to adjust to the appropriate curve. Certainly worth it to me to get the best of these recordings. Believe me it was a hassle I wouldn't bother.

 

I have one of these. It sounds great, and is very tweaky (scroll down to the bottom - it does Columbia, Decca, RIAA, eRIAA etc.):

http://www.ifi-audio.com/en/iPhono.html

Edit: Doesn't do 78 RPM which apparently is the main issue in this thread, but I still think it could be potentially useful.

 

Wow. Pretty cool. My point is that applying correct curves can help with older lp's, not just 78's. So yeah, this looks like it would be beneficial. How much is it?

 

I'm just starting to experiment with 78s, and revisited 4 in particular that my aunt and uncle had given to my brother and I - the attic in this old house they bought had a bunch of 78s and they randomly gave us these 4 (somehow I managed to save them for the better part of 35 years and they're still playable, not broken). About 6 or 7 years ago, I bought an older Stanton professional (broadcast?) type phono preamp that has a NAB setting. I finally connected it to my Elac Miracord 50H-II turntable with Shure M97 Era IV with N978E stylus, and playing a 78, I tried it with the NAB setting on. This got rid of a lot of the surface noise, yet the recording itself didn't seem any more "masked" by the setting. The one particular record I was playing was recorded in late 1918, released in 1919 (according to info online), on Columbia label, and was obviously a song in the spirit of the WW1 victory). It's amazing to think that this recording is 94 years old and still playable today! How cool is that?

 

Just to make things even MORE fun...

The equalization curve for electric 78's were established when crystal phono cartridges were the norm. However, magnetic cartridges have a frequency-dependent response, rising 6 dB/octave from bottom to top, which is the difference between constant-amplitide and constant-velocity. So, when playing 78's with a magnetic cartridge, an additional rolloff needs to be applied. I don't know whether modern 78 RPM preamps take that into account or not.

That's part of the reason for the RIAA curve. It came into effect right about the time when magnetic cartridges were starting to appear. So RIAA for 78's isn't perfect, but it's close, and all you need to do for 78's is turn the bass down a little.

 

$399 USD.

 

It had a very favourable review in the current edition of Hifi World I might add.

 

I have a Graham Slee Jazz Club, and while I don't have any frame of reference for comparing it to other component phono preamps, I can say that for LPs it readily trounced the various non-discrete preamp sections that I've had, and it's a joy with 78s. There are cheaper ways to go--even purchased used for about half list, the Jazz Club was a major equipment investment by my cheapskate lights--but I consider every penny money well spent. On the whole, I'm inclined to think its "apply the chosen curve from scratch" approach is probably preferable to that in some other units, such as ones available from KAB, that apply ajustments to a signal already compensated for RIAA equalization, although I have no personal experience to back that up, and I know that units of the latter sort are generally more economical and have plenty of satisfied users.

Incidentally, after buying my unit I wrote the company with a question, and I was surprised to receive a reply from Graham Slee in person. In our ensuing brief correspondence, he was most gracious, and he offered a clear explanation of the subject at hand, how "flat" playback of acoustic recordings is surprisingly difficult to implement because of magnetic cartridges' output vs. frequency issues to which others have referred in this thread. He certainly came across as knowledgeable and passionate.

 

These controls have become invaluable to me when playing older LP's and 78's.

 

Looks similar to the settings on my parents' old Silvertone console - except instead of "LON", it had "FFRR".

 

If you don't have one of the above preamps, you can use a Y adapter to parallel the output of your turntable and feed it into a Hi-Z microphone input then through an equalizer to play your 78s and tailor the sound to what sounds most natural to you. I have discovered than many 78s from the late 20s and 30s actually have bass in the grooves. Playing them with RIAA compensation rolls off the highs (which are actually IN the grooves on 78s) and boosts the lows. The Columbia LP compensation in preamps rolls off the bass. FFRR/LON is a confusing curve because it can apply to both 78s and early LPs. Early Capitol LPs used the AES curve, which was not appropriate for 78s. The 78 position on preamps was rather generic and didn't particularly conform to any single label's curve. I'm surprised that a few of these preamps woth Turnover and Rolloff didn't have an Ortho setting, which was one that was used for RCA and Victor 78s and should not be confused with "New Orthophonic," which was the compensation curve adopted by the RIAA. RCA often pressed for other labels too, but if you didn't know which ones, reproducing them properly could be a crap shoot. I know RCA pressed 78s for Cadence and Dot, among others. American Decca & Coral LPs used either the AES or NAB curve, depending on when a record may have been pressed. Mercury used AES while MGM used NAB for LPs, but RIAA for 45s (then called "New Orthophonic") AND 78s! Now here's a mindblower: Columbia used LP for LPs, but AES for 45s! You'd have thought they would have used their own curve for both, but they didn't. Here's a good link to who used what curves and when: www.arsc-audio.org/journals/v20/v20n1p14-23.pdf.