RIAA Equalization Standard...

[ThorstenL]

Hi,

Originally Posted by flavio81

Not for the supposedly different curves for __Stereo__ Decca and DGG records. Please provide a reliable source. They're not on the "sound restoration" manual, AFAIK.

No, they are not. I grew up in eastern europe where the LP EQ was CCIR, so maybe I am more open to the concept that others may also exist.

Originally Posted by flavio81

Ok, so you don't want to list the sources.

Most I CANNOT list, if you read my earlier post.

Originally Posted by flavio81

If you are a fellow DIY/electronics hobbists, you will understand the great benefit that we all could get if you would provide actual reliable sources of different EQ standards for **stereo** records.

All the Stereo curves equal the more or less last mono ones...

Ciao T

[flavio81]

Originally Posted by ThorstenL

Most I CANNOT list, if you read my earlier post.

Thorsen, what you are saying is that you can't list sources for the usage of equalization other than RIAA on stereo records because "some [of the sources] explicitly asked to not be named". Did i understood it correctly? So equalization curves' usage can be top secret?

Anyways, it seems that we can reach an agreement. If i understood correctly what you are saying is that for example, some stereo records in eastern europe were cut with the (mono) CCIR equalization [450 us and 50 us] standard? That would make much more sense.

But then your AM77 manual states that it comes with these curves:


My primary point of contention is on the "DECCA (FFSS)" item, if what you are claiming is that Decca did not conform to RIAA on their FFSS stereo records. The edit that SOMEONE did to the related Wikipedia page on record equalization, suggested that. This infuriated me a lot. I tried to search for any reference that could support that and the only reference was you AMR guys. This infuriated me more. And no, i didn't limit myself to a "quick" google search.

Now if you could find the frequency response curves for the Telefunken-Decca ZS 90/45 head (made by Neumann), we could find an objectively better equalization "tweak" for those early stereo records cut with that head, and everybody will win on this forum. I'm afraid i would need an AES membership to get them.

May the schwartz be with you. I see your Schwartz is as big as mine. Or bigger.

Greetings,
F.

[john curl]

Thorsten has made an important point. For SOME record collectors, multiple curves are necessary, however, for most everyone else, RIAA is good enough. It is a bit like MC cartridge loading. 100 ohms will serve most MC cartridges well, however it would be useful to have a whole range, to take in EXOTIC phono cartridges and give them their ideal loading. But most people won't bother, and just leave the loading at 100 ohms or perhaps 47K.

[Telemann]

Originally Posted by flavio81

Thorsen, what you are saying is that you can't list sources for the usage of equalization other than RIAA on stereo records because "some [of the sources] explicitly asked to not be named". Did i understood it correctly? So equalization curves' usage can be top secret?

Anyways, it seems that we can reach an agreement. If i understood correctly what you are saying is that for example, some stereo records in eastern europe were cut with the (mono) CCIR equalization [450 us and 50 us] standard? That would make much more sense.

But then your AM77 manual states that it comes with these curves:


My primary point of contention is on the "DECCA (FFSS)" item, if what you are claiming is that Decca did not conform to RIAA on their FFSS stereo records. The edit that SOMEONE did to the related Wikipedia page on record equalization, suggested that. This infuriated me a lot. I tried to search for any reference that could support that and the only reference was you AMR guys. This infuriated me more. And no, i didn't limit myself to a "quick" google search.

Now if you could find the frequency response curves for the Telefunken-Decca ZS 90/45 head (made by Neumann), we could find an objectively better equalization "tweak" for those early stereo records cut with that head, and everybody will win on this forum. I'm afraid i would need an AES membership to get them.

May the schwartz be with you. I see your Schwartz is as big as mine. Or bigger.

Greetings,
F.

I believe a careful reading of the very extensive run-through found at hifimuseum.de (in English) of the various curves in use, and when changes were made to RIAA, will help calm down most frayed nerves.

AMR themselves declare that the DMM RIAA they are offering is one they have developed, to help DMM-records sound better. It's not a standard that was in use when DMM was launched, as far as I can understand.

• RIAA DMM - (The RIAA ‘Direct Metal Mastering’ Curve is not a standard EQ Curve. This ‘AMR Curve’ was developed specifically to correct for the commonly found ‘bright’ and ‘metallic’ edge of DMM recordings)

Now on to hifimuseum.de
To spare people having to read for hours (it's that thorough), one can jump to section 6.60 and onwards. The writer shows when Decca switched to cutters calibrated for RIAA, and has done extensive testing to try and find non-RIAA records from the period after.

I have not been able to find any confirmation that DGG stuck to its guns far into the 60s, but would appreciate receiving same, as that is an interesting claim.

Jump to 6.60 and onwards:
hifimuseum.de - Sie sind im Bereich : Sound-Restoration-Teil 6

[Telemann]

Eastern European use of CCIR is interesting, as it explains why many find the records from the 60s/70s/80s to sound "megaphonic" - well, I have tried playback with the correct curve, and it's a revelation. Guess I shouldn't write as much, as these are often fantastic recordings, just not through RIAA, and they are very cheap to buy still.

[jlsem]

So, how different is the CCIR 56 equalization curve from the RIAA standard? Was it used for stereo Melodiya, Supraphon, Polskie Nagrania Muza, and Hungaroton records?

John

[Telemann]

Stereophile gave it a detailed look, with measurements, using the AMR PH-77 adjustment curves:

Abbingdon Music Research PH-77 Phono Equaliser Measurements | Stereophile.com

[Soundminded]

The only reason RIAA gave relatively if not entirely consistent result vis a vis tonal balance compared to CDs is that in the era that phonograph records were manufactured, it was SOP for studios to carefully equalize their monitors to have a flat FR. This resulted in similar although not identical results from different record companies because balance engineers heard approximately the same thing even though their speakers were different. Where there are differences or errors, a graphic equalizer is an excellent way to make corrections. Today with equalizers widely in disrepute among audiophiles who now include probably most recording engineers, spectral balance from company to company and even recording to recording in the same company is all over the lot. Unless you equalize for each recording individually they all sound awful, always very wrong for one FR distortion reason or another.

[jlsem]

Originally Posted by Telemann

Stereophile gave it a detailed look, with measurements, using the AMR PH-77 adjustment curves:

Abbingdon Music Research PH-77 Phono Equaliser Measurements | Stereophile.com

That would explain the "dark" sound of Melodiya records.

John

[piano3]

As far as I know, CCIR has 3180, 450 and 50 microseconds. I agree with John about the characteristic sound of Melodiyas which I had always attributed to their microphones.