Mark Levinson, the archguru of ultra
hi-fi musical reproduction, has stopped recording music
on conventional CDs. He no longer even listens to them.
And, while his name still is burnished on some of the world's
most expensive CD players -- the Mark Levinson Reference
CD Player, for example -- by a company which bought his
brand, and name, years ago, he discourages clients at his
own company, Red Rose Music, from buying conventional CD
gear. Instead, he records all his music in the new Super
Audio CD format (SACD) and recommends to his customers that,
if they want digital music, they buy SACD players.
SACD, which was recently launched in
America by Sony and Philips, the same partnership that,
a quarter century earlier, developed and patented the CD,
is identical to the CD in its dimensions and appearance
but has a different and far superior way of encoding and
decoding digital sound.
Mr. Levinson explains that this change
is crucial to the future of digital sound. "SACD addresses
what has become an international epidemic: PCM." PCM, which
stands for Pulse Code Modulation, is the operating system
used for all digital sound -- CDs, movies, television, DVDs,
computers, etc. -- with the exception of SACDs. Mr. Levinson's
concern about PCM goes beyond the quality of the music it
reproduces. He believes that PCM induces toxic stress in
The Sony executives responsible for
marketing this new format do not share Mr. Levinson's view
about the toxicity of PCM. But they acknowledged that there
were sonic problems with PCM, which had resulted in reports
of "listening fatigue," as David Kawakami, who directs the
Super Audio project for Sony, put it to me. All agreed that
SACD was vastly superior. So why had PCM become the standard
for digital sound?
Mr. Kawakami explained that PCM had
come about as an engineering solution to "a bit-management
problem." In the early 1980s, Sony stipulated two requisites
for developing digital sound. First, the container itself,
which was the CD disk, could not be more than 4.75 inches
in diameter -- a dimension that would allow CD players to
meet the European standard for an audio player on an automobile's
dashboard. This meant, given the state-of-the-art technology
then, that the CD could not hold more than 650 million bits
of data. Second, it had to be capable of playing at least
70 minutes of music -- the length of a typical symphony
-- which required more than 2.5 billion bits of digital
To meet these seemingly contradictory
requirements, part of the signal had to be eliminated, but
without degrading the sound so much that it became unacceptable
to the public. Enter PCM. This ingenious electronic fiddle
truncated the original bandwidth from 100,000 to 20,000
hertz, since humans cannot normally hear frequencies above
15,000 hertz, and "sampled," or took a digital snapshot,
of the remaining information 44,000 times a second. This
doctored data was repackaged into 16-bit packets capable
of playing back a symphony in 74 minutes or less.
Of course, the acoustical engineers
who invented PCM knew that the condensed 16-word product
would be inferior to the original: For one thing, filters,
on both the encoding and decoding ends, cause audible "errors."
For another, chopping out all the information between 20,000
and 100,000 Hertz reduced the harmonic depth of the music
itself. Still, PCM did provide a highly convenient means
of getting sound, or its approximation, to the masses. Sony,
with its partner Philips, gradually managed to convince
enough people that the PCM CD offered superior sound to
LPs and that its aural replication of music was . . . perfect.
They and their licensees have so far sold roughly one billion
CD players and 20 billion CDs.
Some diehard audiophiles refused to
settle for the Procrustean world of PCM. They spent as much
as $10,000 and more for digital-to-analog converters designed
to ameliorate the filtering errors in PCM. But even the
most expensive outboard digital gear could not restore the
missing bandwidth. By the mid-1990s, however, digital sound
technology had taken a giant step forward, enabling Sony
to exorcise the PCM demon.
The answer was already for sale in every
consumer electronics store in the world: the DVD. Originally
developed to store digital video, the DVD player had a laser
which could read marks packed much closer together than
those on an audio CD. As a result, a DVD could store about
eight times as much data as the CD. Indeed, there was more
than enough room on a DVD to directly stream in single bits
of a digital record of the sound of a 74-minute symphony,
sampled 2.8 million times every second. The difference is
evident when one listens in the Sony studio through earphones
to the actual digital bitstream. With PCM, all that is heard
is a hash of hisses. With SACD, so closely did this digital
stream approximate the original that one can actually hear
the music. And since this streaming did not need to be repackaged
into 16-bit words or truncated at all, no digital filtering
was used. It conveyed the entire bandwidth, audible or inaudible,
up to 100,000 hertz.
Aside from being closer to the music
(see Figure #1), it was simpler than jerry-rigged PCM and,
therefore, cheaper to implement. The Super Audio project,
under Mr. Kawakami's direction, was quickly green-lighted.
By this fall, Sony, once again partners
with Philips, plans to sell SACD players for under $300.
They will also be backwardly compatible with conventional
CDs so that consumers can play the CDs they already own.
Some 200 SACDs have already been issued.
Being an early adopter, I bought an
SACD player as soon as it was available. But then I discovered
my very expensive ($10,000) pre-amp redigitalized the SACDs
into PCM. Aside from this sophisticated circuitry, there
was the problem of the volume control. Like that of many
other pre-amps, mine filtered out all bandwidth over 20,000
hertz. That is because, before the introduction of SACD,
sonic information over 20,000 hertz would be heard as unintended
noise. So I still was not getting the full benefit of SACD.
Surfing the Internet with key words
like "audiophile" and "volume control," I then found in
Boise, Idaho, something called a passive volume attenuator,
made by Placette Audio and sold for $1,400. By using several
dozen precision resistors, costing about 300 times as much
as a conventional volume control, the Placette was capable
of controlling the volume from the SACD without filtering
out any of its bandwidth.
Once I had hooked up my Placette, I
was finally able to listen to unadulterated PCM-free music.
I listened on available SACDs, selling for about $25 --
everything from jazz and church choirs on the DMP sampler
I bought to classical Bach on an acoustical guitar and a
Rupert Brooke poem, read by "Sex and the City" actress Kim
Cattrall (who is Mark Levinson's wife) on Red Rose Music's
After two weeks of listening, and comparing
CD and SACD tracks of the same original recording, I can
say unequivocally that I have heard the future, and it is