CD : qualité audio - meilleures versions

Un échange de courriers assez édifiant entre Mats Schorling et John McDermott sur les rééditions d'Experience Hendrix LLC :

DIGITAL CLIPPING IN EXPERIENCE HENDRIX FAMILY RELEASES

Mats Schorling of Sweden discovered some clipping in the new EH releases, and believes the error is in the re-mastering. Several letters were sent to EH, as well as a reputable Audio Magazine.

Here is a copy of some email exchanges between Mats and the estate, dated August 25 1999. Thanks Mats.

Hello!

I just have to yet again make you aware of the technical shortcomings in all of your official Jimi releases. From what I understand, you have transferred most of the original master tapes to 24-bit digital. This is really fine and well, it's really the way to go. But, - there is a flaw somewhere along the line in your transferring process!!!!!!!

Please take a look at the two enclosed pictures. These are screendumps from two very well known digital audio editors, -SoundForge and Cool Edit. The signals are taken digitally from your CD's. (When looking at the signals (from the analogue outputs on my H/K CD player) on an analogue oscilloscope, they look the same). You can clearly see the overloads that occur time and time again in all your releases. This is just a snippet, randomly picked from "Live at Fillmore East". You can take virtually any tune from any CD, and you will see hundreds of overloads in each and every one of them.



View the picture named "CE Stats.jpg" .The two green traces represents the left and right channels. The 16-bit digital signal varies inbetween the technical maximum of 32768 and -32768 levels. Your cd's do indeed stay within these limits, as is shown in the statistics-box in each program. The levels are unusually high, but within the technical limits. So this is OK.

But, as I really hope you see from the pictures, there shouldn't be these flat tops and bottoms close to the technical limits. There are no analog recorded signals that looks like this. The flat parts you see in the signal(for instance at the vertical yellow line in the "CE Stats.jpg") are "perfect" examples of heavy clipping and distortion. The fact that the flat parts are a few levels away from the absolut limits, tells us that the clipping took place before the final mastering of the CD. And the fact that in places where the distortion is so severe that it's actually audible, we can listen to the same instances on your digitally mastered vinyl LP's and hear the same distortion, tells us that these overloads occur on your digital 24-bit archive-tapes.



This is rather sad, as it's both expensive and time consuming to have all this transferring done. And that the tapes that were supposed to preserve Jimi's music far into the future are not up to the best standards that can be achieved today, is a disaster.

Please take a long hard look at the way you do these transfers. Somewhere along the line from the tapehead of the tapeplayer, through EQ's, compressors, gates, limiters etc, and into the 24-bit AD-converter, you have your clippings. It's just so incredibly unnessesary to have these easily avoidably faults on all your releases, when all you have to do is to adjust the levels down 4 to 6 dB, somewhere along the line.

I have made you aware of this problem before, and I write again today because I just checked out your new Woodstock-CD. Same thing! Same flaws!

I've never heard of a similar long line of flawed releases from any other company. Ever. I think this is getting rather silly, and it's not professional in any kind of way!!!!! In fact I think that all your customers should be entitled to exchange all their copies for properly remastered versions. This would indeed be a costly undertaking.

Please, please, set the levels right!!!!! P.S. I also send this letter to

Eddie Kramer
George Marino
John McDermott
Steven Pesant


Peace,
Mats Schorling

________________________________________________________________________
________________________________________________________________________

Message: 8
Date: Sat, 30 Sep 2000 21:01:19 -0000
From: mats.schorling@swipnet.se
Subject: CD distortion (Part 4)

Hello again!
Thanks for the comments (mostly private) about my letters concerning Jimis' original tapes being run too "hot", when they were transfered to digital. Several people wanted to know if the signal looks the same on the vinyl versions. No, they don't. And that's because an analog record isn't a phaselinear media. High frequensies are shifted in time, relative to lower frequensies. Also, recordpickups are in most cases velocity-sensitive devices (the peak level occurs at the steepest slopes of the hills and valleys in the record groove). So any flat portions of a clipping will look completely different from a vinyl record. In this case, we have to trust our ears.

No Jimi CD's prior to the EH releases have audio signal clippings. I agree with John Schultz: To my ears the Reprise RH-1 editions (which I bought in Seattle when they were relesed in 1989) sound best, especially Axis: Bold As Love, which was mastered by Lee Herschberg and not by Joe Gastwirt… However, I would have loved to hear JG's HDCD masterings of Jimi's original albums. (Thank you very much, Owen, for your interesting posting. Can anyone help me with a copy of the Stereo Review's Sound & Vision magazine?)

As the recorded signals are all that remains of the late and great JH, the caretakers have a serious responsability that these recordings will be preserved undistorted for coming generations. The analog masters should be transfered to digital one more time again. Properly and finally. With great care, thoroughness and passion. If Kramer and Marino won't do it, EH should get someone dedicated who will.

I've been going on about this (with a lot of help from two of my friends: One a professional sound engineer and the other a signal analysys specialist (M.Sc.)) from the first re-re-re-release, so I'm not about to quit now. If EH and MCA at least won't acknowledge the problem, I will be forced to bring it to the attention of the media: HiFi and music magazines, radio, TV. Whatever it takes. This is not about some little come-and-go Top 40 single being a little distorted. This is about the digital 24-bit masters that will be used for preserving the legacy of Jimi Hendrix into the future - being FLAWED!!!!!

Peace,

Mats Schorling




________________________________________________________________________
________________________________________________________________________

Message: 9
Date: Sat, 30 Sep 2000 21:02:33 -0000
From: mats.schorling@swipnet.se
Subject: EH's reply on digital clipping

November 16, 1999
Mats Schorling
Bergsliden 30
SE 461 71 Trollhattan
Sweden

Dear Mats:
Thank you for your most recent letter. I am sorry that it has taken me some time to get back to you. I have shared your letter with both George Marino and Eddie Kramer and once again, I am afraid that their answers are not what you wish to hear. It appears from our perspective that we simply have to agree to disagree.
Without bothering to delve into the process of how you created your readings or data, George Marino wanted to make clear that you understood his viewpoint that the mastering process, like mixing, is a subjective art based on the human ear and not solely meters or other technical data. A few corrections you should note from your letter. George did not master the Hendrix recordings at 24 bit. They were mastered using 20 bit technology. You are entirely incorrect in both your reasoning and assessment that the `clipping' you describe `took place before the final mastering of the CD'. Actually, Jimi's original analogue tape `flat' masters were used for the mastering. These were then transferred to a digital medium during the final mastering of the CD's. As I mentioned previously, the Hendrix discs mastered at Sterling
Sound are done at full volume. We recognize fully that this is unlike any previous Hendrix release issued by either Polydor, Reprise, or pre-EH MCA. The mastering techniques utilized for such releases as Live At The Fillmore East and Woodstock are no different from other contemporary CD releases mastered at Sterling Sound. These artists range from Metallica to Led Zeppelin to Guns N Roses to even Whitney Houston. Moreover, one can not directly compare the previous Hendrix CD
releases with the current EH versions as different analog tape sources were used. Problems which stem from using older safety copies-such as the speed problems heard on the pre-EH Ultimate Experience release--are entirely unrelated to the mastering process. We were able to bypass all of these issues by simply utilizing Jimi's original master tapes. As for the distortion which you claim to hear on our releases, I would strongly suggest that the example you cite is the clear explanation as to our point, namely that you are now hearing as much detail from the original flat masters as technically possible. There are numerous examples marbled throughout our releases, such as "Freedom" from First Rays Of The New Rising Sun, where you are now hearing tape distortion on the original master that was previously inaudible on older vinyl and CD releases. This is absolutely not something caused during or after the mastering process. While we may not agree, I hope I have provided you with a sufficient understanding of our position regarding the queries you presented. Thank you again for your interest and support of Jimi's music.
Kind regards,
John Dermott




________________________________________________________________________
________________________________________________________________________

Message: 10
Date: Sat, 30 Sep 2000 21:04:59 -0000
From: mats.schorling@swipnet.se
Subject: Our reply to EH on digital clipping

Hello John!
Thank you very much for your reply. It didn't straighten all my question marks, but now I think I know where and when the catastrophical digital clippings take place.

>Dear Mats:
>Thank you for your most recent letter. I am sorry that it has taken
>me some time to get back to you.
>I have shared your letter with both George Marino and Eddie Kramer and
>once again, I am afraid that their answers are not what you wish to
>hear. It appears from our perspective that we simply have to agree to
>disagree.

I still want you to agree with me. My One Rainy Wish is for you to produce Jimi CD's sounding as good as possible. Something which hasn't been the case so far, because of the countless digital clippings on the EH releases.

>Without bothering to delve into the process of how you created your
>readings or data, George Marino wanted to make clear that you understood
>his viewpoint that the mastering process, like mixing, is a subjective
>art based on the human ear and not solely meters or other technical
>data.

Well, there are good artists and bad artists... To transfer a signal from analog to digital without clipping it, is really a piece of cake. The reason I began to "investigate" the EH releases was because, when playing them physically loud, like I have done with my Jimi records since 1971, I began to feel slightly "ill" and had to turn the volume down. There was something wrong with the sound going into my body and soul. I now understand that this feeling was caused by the digital clipping, which is something unnatural.

>A few corrections you should note from your letter. George did not
>master the Hendrix recordings at 24 bit. They were mastered using 20 bit
>technology. You are entirely incorrect in both your reasoning and
>assessment that the `clipping' you describe `took place before the final
>mastering of the CD'. Actually, Jimi's original analogue tape `flat'
>masters were used for the mastering. These were then transferred to a
>digital medium during the final mastering of the CD's.

John, I find you a bit vague here. Surely they didn't transfer Jimi's original analog 2-track master tapes to 16-bit digital "on-the-fly", when making the "Mother" glass CD. You don't seem to make a clear distinction between "Mastering" and "Final mastering". What I call "Mastering" is when the analog tapes are transferred to digital tape (20 bits, from what you say). What I call "Final mastering of the CD", is when the 16 bit glass "Mother" is prepared.

>As I mentioned previously, the Hendrix discs mastered at Sterling
>Sound are done at full volume. We recognize fully that this is unlike
>any previous Hendrix release issued by either Polydor, Reprise, or
>pre-EH MCA. The mastering techniques utilized for such releases as
>Live At The Fillmore East and Woodstock are no different from other
>contemporary CD releases mastered at Sterling Sound. These artists
>range from Metallica to Led Zeppelin to Guns N Roses to even
>Whitney Houston.

This triggered me to check a couple of other CD's in my collection mastered at Sterling Sound: R.E.M.: "Up" and the 1999 remix/remaster of Bob Dylan's 1978 release "Street Legal" and both have digital clippings! The 1989 (?) CD release of "Street Legal" (Mastered at CBS Recording Studios, N.Y.) has no clippings! I also checked several other CD's NOT mastered at Sterling Sound (f.i. the Stevie Ray Vaughan remasters, the The Beatles "Yellow Submarine Songtrack" remixes, C.S.N & Y: Looking Forward and Matthew Sweet: In Reverse) and none of them have clippings. From this I conclude that there is "something wrong, something not quite right" at Sterling Sound.


>Moreover, one can not directly compare the previous Hendrix CD releases
>with the current EH versions as different analog tape sources were used.
>Problems which stem from using older safety copies-such as the speed
>problems heard on the pre-EH Ultimate Experience release--are entirely
>unrelated to the mastering process. We were able to bypass all of these
>issues by simply utilizing Jimi's original master tapes.
>As for the distortion which you claim to hear on our releases, I would
>strongly suggest that the example you cite is the clear explanation as
>to our point, namely that you are now hearing as much detail from the
>original flat masters as technically possible. There are numerous
>examples marbled throughout our releases, such as "Freedom" from First
>Rays Of The New Rising Sun, where you are now hearing tape distortion on
>the original master that was previously inaudible on older vinyl and CD
>releases. This is absolutely not something caused during or after the
>mastering process.

I have heard the analog distortion on "Freedom" and other songs since 1971, but Sterling Sound has added digital distortion (by clipping the peaks) to them, which, as I wrote in my letter to you, is totally unnecessary, considering the dynamic range of the CD medium. I enclose two identical CD-R's with "Freedom" from five different
releases for you to make an A/B test. Please, John, listen with your "heart and ears" at home and I'm sure you'll hear on which versions (especially one of them) Jimi, Mitch, Billy, Juma and The Ghetto Fighters are almost present in your living room and on which the body of Jimi's guitar is made of wood (not steel) and his and TGF's voices are alive, Mitch's drums have real skin and don't sound like metal cans, Billy's bass stand out and is integrated with the music at the same time, all this making you to want to play the song over and over.

>While we may not agree, I hope I have provided you with a sufficient
>understanding of our position regarding the queries you presented.
>Thank you again for your interest and support of Jimi's music.
>Kind regards,
>John Dermott

The reason I delve into this matter, is that I care for Jimi and his music, so please make future CD masterings at another studio than Sterling Sound.

Peace,


Mats Schorling

Source : http://home.pacific.net.au/~spaceman/jimi/clipping.htm

Un classement trouvé sur le forum de Steve Hoffman :

1. Japanese Polydor P20P series.
2. Japanese Polydor P33P series.
3. West German Polydor.
4. Early Canadian Warner Reprise.
5. Early US Warner Reprise, before noise-reduction was added.

Quelques infos à propos des fameuses P20P series :

About the Japanese Polydor P33P series of Hendrix CDs, these discs of Hendrix titles are quite nice sounding, the sonics are phenomenal and there is no use of any digital limiters. It happens that back in the old days, like the late 1960's and early 1970's, Polydor had the original master tapes of the Hendrix catalog, and these tapes were preserved in the vaults of Polydor in England.

When CDs came into the picture, these original master tapes were sent to Japan, to JVC, to create digital masters because England did not have any digital transcrïption equipment at that time. These digital masters were created to be sent around the world, i.e. the Polydor pressing plants in Argentina, Australia, West Germany and England. While the tapes were at JVC in Japan, the tapes were sent across town to Polydor headquarters in Japan and transferred straight from the original master tapes to an analog umatic safety tape, and it these original analog safety tapes that are the source of the very early Japanese Polydor P20P series and the P33P series CDs. It must be remembered that only these CDs are sourced from these original analog umatic safety tapes, even the very early West German Polydor CDs and the English Polydor CDs are sourced from a digital master tape, although these digital masters were sourced from the original master tapes themselves.

Both the P20P series and the P33P series of Hendrix CDs were manufactured from about 1984 through about 1988, and because of this relatively short manufacturing period, are all highly collectible. There are significant differences between the 2 series of CDs; the P33P series of CDs generally have the same mixes as the West German Polydors and the Warner Brothers, and the P20P series often contained mixes that were unique to that series only. Two titles come to mind for this type of variation between the 2 different series.

Everybody knows that the ARE YOU EXPERIENCED album came out first in England on Polydor records before it was released in America. The album was released in August of 1967 on Polydor of England, Sept. of 1967 on Trax Records in England and also Sept. of 1967 on Barclay Records in France. It was not released until October of 1967 in America and then it came out on Warner Brothers Records. These various copies of this now classic album were all significantly different; they had different cover artwork and contained different songs or different mixes of songs.

The only thing that all of these releases had in common was that they had same album title. Well that is the vinyl history of ARE YOU EXPERIENCED, but the CD history is quite a bit different because by the time CDs came out in 1983, the copyrights of Hendrix material had went through several different court rulings has changed hands several different times.

The very first CD pressing of ARE YOU EXPERIENCED that I am aware of is the West German Polydor which came out in early 1984. This CD contained the very original UK Polydor vinyl version of the track listing and mixes as well as cover artwork.

After this CD release, Warner Brothers in America released the original American vinyl version of ARE YOU EXPERIENCED on CD in late 1984, this would be the now very collectible CINRAM CD edition. The DIDX CD which came out in 1985 was very slightly different in the actual running times of some songs, but the DIDX and the CINRAM are basically the same mixes, just different fade outs.

Notes:
The P20P series were released in 1989.
The P33P series were released from 1985 - 1987.
Most of P20P releases have a P33P matrix.
The exceptions are Loose Ends,War Heroes,Electric Ladyland,Are You Experienced,Smash Hits and Kiss the Sky.
Loose Ends and War Heroes didn't geta P33P release.
Are You Experienced,Smash Hits,and Kiss the Sky didn't get a real P33P release.They were released with the first West German Polydor catalog numbers instead.

Electric Ladyland (P36P) is the same as the P58P release.(P33P series)
The P20P releases with a P33P matrix are identical to the P33P releases.
If you look at the scans of the discs for Crash Landing, Midnight Lightning, Monterey,and The Jimi Hendrix Concerts,the P33P catalog numbers are on the discs. They have been compared, the wav files with EAC, they are the same.
According to some audio forums, the P20P series are superior in sound compared to the P33P series.
The only P33P series title that was not issued with the P20P series was The Singles Album.

Redondant avec l'article précédent, mais pas entièrement :

About the Japanese Polydor P33P series of Hendrix CDs, these discs of Hendrix titles are quite nice sounding, the sonics are phenomenal and there is no use of any digital limiters. It happens that back in the old days, like the late 1960's and early 1970's, Polydor had the original master tapes of the Hendrix catalog, and these tapes were preserved in the vaults of Polydor in England.
When CDs came into the picture, these original master tapes were sent to Japan, to JVC, to create digital masters because England did not have any digital transcrïption equipment at that time. These digital masters were created to be sent around the world, i.e. the Polydor pressing plants in Argentina, Australia, West Germany and England. While the tapes were at JVC in Japan, the tapes were sent across town to Polydor headquarters in Japan and transferred straight from the original master tapes to an analog umatic safety tape, and it these original analog safety tapes that are the source of the very early Japanese Polydor P20P series and the P33P series CDs. It must be remembered that only these CDs are sourced from these original analog umatic safety tapes, even the very early West German Polydor CDs and the English Polydor CDs are sourced from a digital master tape, although these digital masters were sourced from the original master tapes themselves.
Both the P20P series and the P33P series of Hendrix CDs were manufactured from about 1984 through about 1988, and because of this relatively short manufacturing period, are all highly collectible. There are significant differences between the 2 series of CDs; the P33P series of CDs generally have the same mixes as the West German Polydors and the Warner Brothers, and the P20P series often contained mixes that were unique to that series only. Two titles come to mind for this type of variation between the 2 different series.
Everybody knows that the ARE YOU EXPERIENCED album came out first in England on Polydor records before it was released in America. The album was released in August of 1967 on Polydor of England, Sept. of 1967 on Trax Records in England and also Sept. of 1967 on Barclay Records in France. It was not released until October of 1967 in America and then it came out on Warner Brothers Records. These various copies of this now classic album were all significantly different; they had different cover artwork and contained different songs or different mixes of songs.
The only thing that all of these releases had in common was that they had same album title. Well that is the vinyl history of ARE YOU EXPERIENCED, but the CD history is quite a bit different because by the time CDs came out in 1983, the copyrights of Hendrix material had went through several different court rulings has changed hands several different times.
The very first CD pressing of ARE YOU EXPERIENCED that I am aware of is the West German Polydor which came out in early 1984. This CD contained the very original UK Polydor vinyl version of the track listing and mixes as well as cover artwork.
After this CD release, Warner Brothers in America released the original American vinyl version of ARE YOU EXPERIENCED on CD in late 1984, this would be the now very collectible CINRAM CD edition. The DIDX CD which came out in 1985 was very slightly different in the actual running times of some songs, but the DIDX and the CINRAM are basically the same mixes, just different fade outs.

Title ------------------------ Catalog --------------- Matrix
Are You Experienced...............P20P 22001..............P20P-22001-A1D
Axis: Bold as Love..................P20P 22002..............P33P-25023-A2K
Smash Hits............................P20P 22003..............P20P-22003-A2F
Electric Ladyland....................P36P 22004/5............P58P-25001-A2F
Band of Gypsy.......................P20P 22006..............P33P-25022-A2F
The Cry of Love.....................P20P 22007..............P33P-25011-A3C
Isle of Wight.........................P20P 22008..............P33P-25010-A2F
Hendrix in the West................P20P 22009..............P33P-25004-A2E
War Heroes...........................P20P 22010..............P20P-22010-A1F
Loose Ends...........................P20P 22011..............P20P-22011-A1F
Crash Landing........................P20P 22012..............P33P-25024-A2C
Midnight Lightning..................P20P 22013..............P33P-25025-A2E
The Jimi Hendrix Concerts........P20P 22014..............P33P-25038-A2D
Jimi Plays Monterey................P20P 22015..............P33P-25003-A2E
Live at Winterland..................P20P 22016..............P33P-20119-A3F
Kiss The Sky.........................P20P 22017..............P20P-22017-A1F
The Singles Album.................P58P 20112/3............P58P-20112-A2E
.................................................. .....................P58P-20113-A2E

Notes:
The P33P series were released from 1985 - 1987.
The P20P series were released in 1989.
Most of P20P releases have a P33P matrix.
The exceptions are Loose Ends,War Heroes,Electric Ladyland,Are You Experienced,Smash Hits and Kiss the Sky.
Loose Ends and War Heroes didn't get a P33P release.
Are You Experienced,Smash Hits,and Kiss the Sky didn't get a real P33P release.They were released with the first West German Polydor catalog numbers instead.
Electric Ladyland (P36P) is the same as the P58P release.(P33P series)
The P20P releases with a P33P matrix are identical to the P33P releases.
If you look at the scans of the discs for Crash Landing, Midnight Lightning, Monterey,and The Jimi Hendrix Concerts,the P33P catalog numbers are on the discs. They have been compared, the wav files with EAC, they are the same.
According to some audio forums, the P20P series are superior in sound compared to the P33P series.
The only P33P series title that was not issued with the P20P series was The Singles Album.

It is very complicated collecting Hendrix CDs, I know a girl that has over 650 different Hendrix CDs, and they are legit, no bootlegs. This is very funny because in Jimi's lifetime he only made 4 albums:
ARE YOU EXPERIENCED
AXIS: BOLD AS LOVE
ELECTRIC LADYLAND
BAND OF GYPSIES
Just trying to collect these 4 albums alone on CD will give you several dozen different CD copies.
For example ARE YOU EXPERIENCED:
01. Japanese Polydor P20P
02. Japanese Polydor P33P
03. West German Polydor
04. US Warner Brothers CINRAM
05. US Warner Brothers DIDX
06. US Warner Brothers "Are You Experienced, LTD. Edition"
07. Austrailian Polydor with the real nice picture disc, (the now famous "purple haze CD edition")
08. The 1993 Mankowitz MCA remaster
09. The US MCA Experience Hendrix version
10. The Japanese MCA Experience Hendrix edition in minature cardboard cover.
**Most of the above information was taken from an Audio Website, specific

Source: courriel JPIO

Extrait d'un entretien mené dans le cadre des recherches de mon livre :

Ayler: Did you work on the Polydor P20P Japan releases?
Joe Gastwirt: I did not work on the Polydor P20P releases, but have a great deal of insight as to how they were transferred and on what equipment.
The reason I know so much about these transfers is that they were done at JVC in Japan and I was the Chief Engineer for the JVC Cutting Center in Los Angeles, where I originally mastered the LP version of Kiss The Sky.
The P20P transfers were very good sounding for their time period, but the Analog to Digital converters used, as well as the editing system had limited bandwidth and have been outdated since 1990.

Ayler: Have you listen to them? Do you think they are as great as some audiophiles pretend?
Joe Gastwirt: The transfers were done with a high level of integrity and considered "state of the art" at the time.
I think they were audiophile type when released, but I would no longer call them an audiophile transfer.
This is a case where proper technique was followed but equipment used is now outdated.
I think it is typical that when a release appeals to the audiophiles, even when outdated stays (is remembered) in good favor.

Joe Gastwirt, quelques semaines plus tard, en réaction aux rééditions 2010 :

This is pretty interesting, in that every time we remastered under Alan's supervision, we made a decision to go with a different approach, providing the fans with a slightly different product when re-purchasing the same album.
The examples of this are the original Warner release (bad sounding they did not use master tapes), the NoNoised releases (clean but lost a lot of music with the elimination of the noise, but still an improvement over the preceding Warner release), The MCA release (got rid of the NoNoise and implemented better mastering techniques), The final mastering under Alan's supervision was to make the best possible transfers of the master tapes without additional processing (direct wire from the output of the tape playback to the input of a very high resolution analog to digital converter), unfortunately, this last batch was never released as the controlling hands went to Experience Hendrix. The only product that reflected this last mastering was a version of The Ultimate Experience release in the UK by Polydor with notation on the box Special Edition, it was a picture disk with the words HDCD stamped in black around Jimi's belt-line. It is too bad the last versions never did see the light of day, as I believe these were the most representative sounding digital transfers to the master tapes.

Selon lui, le meilleur mastéring n'a ainsi jamais fait l'objet d'une édition officielle, à l'exception de quelques titres sur une édition rare de "The Ultimate Experience".