Print

Print


Tom Fine:

> Also just to be clear here, the CD remastering in
> the 1990's set the bar for quality and fidelity.

The Mastering engineer, Dennis Drake, Polygram, tells it all here:


http://www.themusiclab.net/aespaper.pdf


DIGITAL MASTERING OF THE MERCURY LIVING PRESENCE RECORDINGS FOR COMPACT DISC
RELEASE

Dennis M. Drake, Engineer/Consultant, The Music Lab, Morganville, New Jersey
07751, United States

Abstract:

Music purists believed it was impossible to capture on compact disc the
power and ambience of the original Mercury Living Presence lps. A custom
analog to digital chain was developed with restoration and use of original
tube and film equipment.

Topics include production methods employed, tube versus transistor
comparisons, and the goal of maintaining the original natural sound while
working in the digital domain.

1. INTRODUCTION

As a mastering engineer and audiophile, I was well aware of the legendary
Mercury Living Presence Recordings on LP and the¹ sonic attributes they
embodied. 

As Vice President of Studio and Technical Operations at PolyGram U.S.A. at
the time that the Mercury project was being planned, I knew that it would
pose an exciting challenge to capture the realism and power of these
recordings on Compact Disc. Philips Classics wisely enlisted the aid of
Wilma Cozart Fine, the original producer, to supervise this project.
This paper tells the story of the work and craft that went into the CD
releases of the first twenty-six albums in this series.

2. BACKGROUND

In early 1989, we were given the go-ahead to begin work on the project. The
first task at hand was to start collecting all of the masters necessary for
the first batch of releases. For those not familiar with the Mercury
recordings, masters were in three track format either on 1/2" analog tape or
35 millimeter magnetic film. Using a location recording technique master
minded by the late C. Robert Fine, three precisely placed omni-directional
tube microphones were positioned along the frontal plane of the orchestra.
These microphones were directly fed to the three channels of a Westrex film
recorder or Ampex 350 3 channel, 1/2" inch tape machine. When these
recordings were mastered for LP, the three channels of audio were fed
through a Westrex 1524 tube console for 3/2 reduction and then to the
cutterhead of the disk lathe. The beauty of this approach was in its
simplicity: minimum number of microphones to capture the sound- field,
minimal number of line amps to amplify the signal, and only one generation
of tape or film. No limiting, compression, or filtering was ever placed in
the signal path. It should be noted that during the live mix to disk for
mastering, Pultec tube equalizers were sometimes used to compensate for
cutterhead variations and deficiencies.

3. MASTER TAPE PREPARATIONS AND EQUIPMENT RESTORATION

Most of the original masters that we needed for this project were in storage
in Baarn, The Netherlands. Since it was decided that only first generation,
original masters were to be used for the CD transfers, we had to work out a
system for safe transport of the masters to the United States where the
production work was scheduled to be done. Working with Mr. Marcel Shopman of
Phillips Baarn and Mr. Onno Shultze of the Philips engineering team, we
worked out a program to back-up all of the masters on Sony 3324 digital
multitrack, preserving their 3 channel integrity, before being shipped to
the PolyGram Studios in Edison, New Jersey.

Concurrent with the safety transfers being done in Baarn, restoration work
had begun on the Westrex film recorder, console, and Ampex 1/2 inch tape
machine that were used for the original Mercury Recordings. Mr. Robert
Eberenz, a member of the original Mercury recording team, and Wilma Cozart
Fine had fortunately kept this equipment ³in the family.² In order to
restore this equipment to its original condition, Mr. Eberenz replaced
tubes, capacitors and wiring as required, and performed all of the necessary
mechanical ³tune-ups².

4. DEVELOPMENT OF CUSTOM A/D TRANSFER CHAIN

As Mrs. Cozart Fine and I began our evaluation sessions in April 1989, it
became very clear to us that the A/D conversion process was a very critical
step in our production work. As the producer once described it, the sounds
from different converters were all different ³bowls of soup². We began
auditioning every A/D converter that we could obtain. Our test methodology
was simple: while playing an original master as source, we would switch
between the direct output of our console and the output of the digital
chain. The digital chain consisted of the converter under test feeding a
Sony 1630 PCM Processor. The final link in the chain was the Apogee filter
modified D/A section of the Sony 1630. At times, we would substitute
different D/A converters for listening evaluations, but we always returned
to the Sony converters or the D/A¹s of our Panasonic 3500 DAT machine for
reference purposes.

Our monitoring set-up consisted of a Cello Audio Suite feeding balanced
lines to Cello Performance Amplifiers, which in turn were driving B & W 808
Monitor Loudspeakers. As we compared the various digital converters to the
playback of the actual analog source, we found that the soundstage of the
orchestra was always reduced in width when listening to the digital chain.

 We also found that many A/D converters exhibited a strident string sound,
unnatural sounding midrange, and a loss of air or ambience around the
instruments.

As a production team, we had a golden rule: In every step of the production
process, always compare back to the original source to ensure that it
remains true. To further this goal, we also installed an audiophile quality
turntable and preamp. Using a VPI TNT Turntable with a Van den Hul MC-10
cartridge feeding a Cello P-101 Phono Preamp, we were able to simultaneously
switch between the original master, the digitally processed signal and an
original LP pressing of a particular release. In this way, we were able to
define the particular format signatures of each medium and zero-in on
maximizing the digital transfer for the most authentic sound quality.

After many listening sessions during which we evaluated A/D converters, we
finally selected the DCS-900 as being most true to the original source.
Employing 128 times oversampling technology, this converter had a convincing
solidity of sound and a better soundstage presentation of the orchestra in
comparison to its competition at the time. Using the Liszt Piano Concerto #1
performed by Byron Janis as our master source, we could also hear more of
the air around the instruments and the ambience of the recording hall
itself.

By late 1989, most of our equipment was installed in the Edison studios. As
a matter of interest, we did some experimenting with playback of the 1/2"
inch masters on tube versus transistor tape machines. It was quite evident
that the tube playbacks had a warmer, ³golden² sound with better harmonic
relationships to the musical instruments. The transistorized playback
electronics had a slightly thinner sound, not as rich, with a slightly
metallic, ³silver² sound.

Even though the tube tape machine gave us a slightly higher noise level, it
was an easy choice to justify its use for the project. Not only was the
recreation of the soundfield superior to the transistor electronics, the
tube equipment also gave us the exact reciprocal of the original recording
equalization curve for playback.

In January 1990, we added a final improvement to the digital chain which
made a substantial improvement. Thanks to Gotham Audio in New York, we were
able to demo the prototype Harmonia Mundi BW 102/49 Redithering Module. This
unit uses an advanced noise shaping algorithm which significantly increased
our low level signal resolution and detail. By outputting the digital signal
from the DCS converter in the 24 bit mode, we were then able to redither and
noise shape the signal with this unit and reconfigure the bitstream back
down to the 16 bit world of the Sony 1630 CD mastering format.
Our analog to digital chain was now complete.

5. PRODUCTION METHODOLOGY

In early February 1990, the film and tape masters that we needed for the
first ten releases finally arrived in Edison from Baarn. Fortunately, the
condition of the masters was very good for their age. The 1/2 inch analog
tape was slightly brittle but quite playable. Most masters only needed
minimal resplicing and exercise by winding. Initial rewinding, however, had
to be done very slowly. Sticky splices could actually pull off the oxide
from adjacent layers of tape if rewound too fast. After getting used to
working with the large 35 mm film reels, I gained quite a respect for the
medium. The low noise level, three dimensional soundfield, and full
frequency response were amazing for any format, let alone on masters that
were over thirty years old.

As we began actual work on the first batch of releases, we developed a
routine that carried us through the project. After several experiments with
digital cloning, we decided that all CD¹s manufactured would be made from
first generation digital masters.

In order to preserve the depth and width of the soundstage, we found that
the less digital processing, the better. In order to accomplish this we
would first do the three channel to stereo mixdown through¹ our digital
chain to create the digital master. Simultaneously, we would make DAT
reference copies for listening and evaluation on other playback systems.

We constantly referenced back to the original master and LP pressings to
ensure the integrity of the digital master. In order to avoid digital
editing and copying of the music, it was necessary to assemble our musical
selections by manually syncronizing and punching in on the Sony DMR-4000
Digital Recorder. Proper pause lengths between the musical selections were
determined at this time. Since the producer wished to maintain continuous
room tone between all movements and works, we would then sample and loop
good, ³clean² sections of short room tone and digitally insert this into our
1630 master. In this way, we were able to keep a sense of performance
continuity by avoiding fades to digital black and at the same time keep all
of the music first generation digital.

Our first completed CD master was the ³Balalaika Favorites² by the Osipov
State Russian Folk Orchestra, recorded in Moscow in 1962. As an additional
quality check, we requested that the CD manufacturing plant send us a test
CD before full scale replication was accomplished. This turned out to be an
important decision. Once we received the reference CD back from the plant,
we carefully set up a listening comparison between it and a 1630 digital
clone of the master. Both of the digital sources were switched at the
input of the D/A converter to eliminate any converter-induced differences.

To our surprise, the CD was harsher and more ³digital² sounding, with less
depth in the low frequencies, than the 1630. Upon further investigation, it
turned out that the plant had three different laser beam recorders and that
one of them sounded different than the other two. After making a glass
master of the ³Balalaika Favorites² on all three LBR¹s and comparing the
subsequent CD test discs from each, we were definitely able to identify the
³thinner sounding² lathe. From the information given to us by the plant
engineers, apparently this lathe was configured with different front end
electronics. As they proceeded with standardizing the electronics on all
three LBR¹s, we simply mastered our product on either of the other two
lathes. This gave us an excellent sonic match to our original master tape.

The producer and I were finally satisfied that the CD medium could capture
not only the wide dynamic range, but also the three-dimensional clarity of
the original Mercury Living Presence recordings.

6. UNVEILING TO THE PRESS

After completing the masters for the first ten releases on CD, we decided to
set up listening sessions for the press at the Edison Studios. This would
give them the ability to A/B the manufactured CD¹s with the original
recordings for direct comparison. On June 21, 1990, representatives of the
major audio magazines and the audiophile press gathered at the PolyGram
Studios in Edison, New Jersey. After two separate sessions of blind A/B
comparisons between the CD reissues and the original master tapes, these
critical listeners were unable to consistently identify the source. (1-3)

7. CONCLUSIONS

Several important rules in digital remastering were reaffirmed during this
time-consuming but rewarding project and many new lessons were learned.
Most important of all, no matter what it takes, find and audition the
original analog master for CD transfer. If the master suffers from some sort
of deterioration, then equalized copies or safeties must, of course, be
examined.

Also, seek out assistance from the original producer and/or engineers of the
recording if possible. Their help will add invaluable input and authenticity
to the reissue. Finally, optimize the transfer of the original master by
using equivalent playback equipment whenever possible. This reaffirms the
need for accurate technical information on the master tape box at the time
of recording. In addition to speed, equalization and any applicable noise
reduction for analog masters, tape type and tape recorder used should also
be indicated. For digital masters, sampling frequency and digital format
must also be included.

We were fortunate to have full support on this project from the management
of Philiips Classics. This gave us the creative freedom to restore the
original tube equipment, develop a customized analog to digital transfer
chain, and take the time necessary for thorough comparisons back to the
original master. Maintaining the natural sound of these analog masters in
the digital domain required extreme care and critical listening.

As we all strive to improve the quality of digital in order to make better
recordings, let us not forget to fully utilize our most important tool of
all‹the human ear.

8. ACKNOWLEDGMENT

The author is indebted first of all to Wilma Cozart Fine for the talent,
energy, and dedication to ideals that she brought to this project; and also
to the following: Nancy Zannini and David Weyner of Phillips Classics,
U.S.A.; Russell Hamm of Gotham Audio, N.Y.C.; Robert Eberenz; Marcel
Shopman, Onno Shultze, and Peter C Heuwekemeijer of Philips Classics
Productions, Baarn, The Netherlands.

9. REFERENCES

(1) Richard Freed, ³Mercury ŒLiving Presence¹Comes to Life Again,² The New
York Times (Sept. 28, 1990).
(2) Richard Schneider, ³Mercury Reissues,² Stereophile, pp. 176-181 (Sept.
1990).
(3) Harry Pearson, ³The Gods Reincarnated: The Mercury Olympian Series Lives
Again,² the absolute sound,
pp. 136-144 (Nov./Dec. 1990).
(4) Arthur S. Pfeffer, ³The Living Presence CDs,² the absolute sound,pp.
146-158 (Nov./Dec. 1990).
(5) Ron McDonald, ³Mercury¹s Presents,² Fanfare, pp. 112-117 (Jan./Feb.
1991).


-- 
Best regards,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: [log in to unmask]

Learn from the mistakes of others, you can never live long enough to
make them all yourself.    -   John Luther