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Interior
Inside the unit, the CD-77 screams quality
with its cleanly laid out, modular design.
The substantial power supply employs 14
different but specifically designed
regulators that designer Thorsten Loesch
believes are necessary because digital noise
has a very wide frequency bandwidth. This
approach is claimed to "reduce power supply
noise by a factor of more than 1000 times
compared to standard regulators to result in
the virtual elimination of digital noise."
The CD-77's transport mechanism, a
substantial floating top-loader,
incorporates major proprietary improvements
to an already excellent mechanism. The
transport is custom implemented by AMR using
the Sony K-series transport in conjunction
with the Phillips CD-18 servo system.
Eschewing the conventional approach to
jitter, AMR developed its proprietary
OptiClockLock®system. AMR believes a major
misconception abounds in the industry
regarding CD source clock crystals –
specifically, that, in terms of absolute
frequency, "high precision is good."
According to Loesch, conventional players
use several generic clock crystals of
mediocre commercial grade to accomplish
jitter reduction (and this includes the
so-called "super-clocks"). More importantly,
Loesch claims all of these clocks have one
further critical weakness -they all generate
signals that are out of synch with each
other. This allegedly results is unwanted
beat frequencies, higher overall digital
noise and increased jitter levels.
Accordingly, rather than emphasizing
absolute frequency precision, AMR submits
that designers should concentrate on two
more critical factors to maximize sonic
performance: (1) the phase noise of the
clock that creates jitter; and (2)
synchronization of all clocks. To address
these issues, AMR’s OptiClockLock® system
ensures that all the clocks in the CD-77 are
purposely synchronized to one
temperature-compensated, low-jitter master
clock module with its own dedicated power
supply. This produces claimed noise
performance at the limits of what’s
physically possible.
The CD-77's digital-to-analog conversion
embraces the “old school.” Around almost as
long as the CD itself, the venerable Philips
TD1541A DAC chip is AMR’s chip of choice.
This rare, vintage chip has a loyal
following. AMR purchased a large consignment
of Philips TD1541A chips a few years ago (as
well as the NOS tubes used in the CD-77) and
AMR assures us they won’t be sold out any
time soon. Many audiophiles tout the “double
crown” version of the TD1541 chip for its
alleged superiority over the single crown
(standard) version. AMR extensively analyzed
the TDA1541A and discovered that properly
designed external circuitry can reduce the
performance gap between the double crown and
standard chips. Since the TDA1541A uses
external digital and analogue filters
(unlike later generation DAC chipsets where
digital and analogue filters are located
inside the chipset preventing any
modification), AMR was free to choose the
optimum solution for digital and analogue
filtering. AMR’s conditioning circuit uses a
Texas Instruments DSP (digital signal
processing) digital engine giving the user
six (6) different sampling settings - from
Direct Master without any digital
filtering/processing (called Digital Master
I) or using AMR’s proprietary analogue
filter (Digital Master II), to 2x and 4x
over-sampling all the way to 96kHz and 192
kHz upsampling. In essence, the CD-77
comprises a six-in-one CD player adjustable
on the fly to accommodate the most
discriminating audiophile.
 Finally,
the CD-77 utilizes six NOS tubes for power
supply regulation and in its analog output
stage. A pair of EZ80/EZ81/6CA4 valves is
used for dual mono rectification while a
pair (one per channel) of ECC81/12AT7/6072A
tubes is used for gain and a pair of 5687s
(one per side) is used in the output stage.
But
Can the Fat Lady Sing?
You bet she can! Let me cut to the chase -
the AMR CD-77 just flat out knocked my socks
off!! Oh I can hear the Doubting Thomas’s
already: “Not another rave review by a
‘component du jour’ reviewer?” Hardly.
Residing comfortably in my system for over
four years, my reference Reimyo CD-777
hasn’t been seriously challenged and the
challengers have been formidable. Excellent
players such as the EMM Labs CDSE and DCC 2,
the Nagra CDP, the Meridian G08 and various
modified Sony players graced my system
during that time. While each challenger had
its relative strengths and weaknesses, the
Reimyo always prevailed … that is until the
AMR arrived, but I am getting ahead of
myself.
For this review, I placed the CD-77 on the
top shelf of my Silent Running Audio CRAZ
Rack fitted with the same interconnects and
power cord that fed the Reimyo. This placed
both players on a level playing field. The
AMR was a breeze to hook up and the remote
very intuitive. Turning on the CD-77 engages
its 45-second warm-up circuit. After
start-up (or after any listening session)
the player can be switched, via remote or
its front panel, into “Standby” mode. This
keeps the player’s digital circuitry active
but cuts the power to the tubes thus
prolonging tube life. I found that the CD-77
sounded best after being on for a while.
 First
up, I reached for one of my favorite CDs and
a new reference torture disc - Let the
Healing Begin by Santa Fe and the Fat
City Horns. This fabulous 15-piece
horn/funk/jazz group is comprised of
professional musicians from the Vegas show
circuit who unite on Monday nights to do
their own gig as the house band at the Palms
Casino and Hotel. Even better, the show is
absolutely free! Check them out next time
you are in Vegas or at CES, you’ll be in for
a real treat! This live disc is explosive
and powerful with excellent dynamics. At CES
2008, while talking with my buddy, Jeff
Smith of Silversmith Audio, I asked the
exhibitor to play this CD. On the first cut
“Ain’t That Peculiar,” a dazzling 6-piece
horn intro gives way to a thunderous bass
driven melody. Jeff commented that the music
was great but the recording was bad (too
bright). Jeff was correct about the music
but it wasn’t the recording that was bad.
Through the CD-77 in my system, even at
concert levels, there wasn’t a hint of
brightness and the brass never made me
wince. Even as trumpeter extraordinaire Gil
Kaupp blasts into the upper register, his
tone stays full with the bite and edge a
soaring trumpet possesses. I know this
because literally five hours after Jeff and
I heard this cut at CES, we went to the
Palms Hotel and heard the band play it live.
While the real thing was understandably more
exciting, the CD-77's reproduction captured
the true essence of the band’s rhythmic
drive and, more importantly, its soul. I
attribute much of this to two things - the
CD-77's absolute linearity and its
non-editorialized tonal color.
The CD-77's bandwidth and spectral balance
is unmatched by any player I’ve heard. From
top to bottom it doesn’t bloat,
editorialize, romanticize, emphasize or
de-emphasize any single band throughout the
frequency spectrum. I’ve always maintained
that a reviewer should never paint
him/herself into a corner by declaring any
component to be the “absolute” best. My
reason for this philosophy is simple - I’ve
not heard every component and my perspective
may change if and when something better
comes along to reveal the limitations of a
previous “reference.” Thank God for that
disclaimer. The Reimyo CD-777 has remained
my reference for almost five years due, in
large part, to its even-handedness. While it
may lean slightly toward the rich side of
neutral, the Reimyo was seemingly equally
adept from top to bottom. The AMR CD-77,
however, revealed areas where the Reimyo
falls short of providing a truly balanced
attack.
The low frequency performance of the CD-77
was stunning in every aspect. From the upper
bass down to 40Hz and below, the CD-77's
low-end is articulate, tonally accurate, and
impactful with foundation shaking extension.
Subtle nuances are easily heard. Mid-bass is
tight and punchy with outstanding transient
attack and harmonic decay. This infuses the
music with rhythmic drive yet does so
without imposing on the music’s crucial
midrange.
If you think tubed players can’t do bass,
think again. The tubed CD-77 bettered the
solid-state Reimyo in every area you’d think
transistors would have the edge. Big
Horizon by David Wilcox [1994 A&M
Records 31452] was one case in point. On
track #1 “New World” and track #9 “Strong
Chemistry”, the CD-77 reproduced the
electric bass lines with such clarity and
balance that the Reimyo’s presentation
sounded ripe and bloated by comparison.
Wilcox’s close-miked acoustic guitar can
sound almost like a bass through many lesser
players. Through the CD-77 you never get
them confused. The AMR’s low-bass extension
bettered the Reimyo’s digging deeper with
greater authority with the proper source
material. Victor Wooten’s subterranean
electric bass on “Sojourn of Arjuna” from
Bela Fleck and the Flecktone’s Left of
Cool [Warner Bros. 9-46896-2] provided
the sonic fireworks. While there may be CD
players that produce more bass, I’ve not
heard any with better bass.
It took a while to realize just how good the
midrange of the AMR was. Why? This is where
the Reimyo truly excels. Yet when the dust
settled, the AMR came out on top. While not
quite as rich as the Reimyo’s, the CD-77's
midrange is just as musically satisfying and
more tonally correct. I’d say it was more
“neutral” but this can imply a relative
leanness. The AMR again revealed how the
Reimyo’s midrange errs on the fuller, richer
side of neutral. It is precisely this
quality that makes the Reimyo such an
engaging player in my book and why it’s been
my reference for so long. My reference took
an uppercut to the chin, however, on the
late Chris Jones’ fabulous CD, Roadhouses
& Automobiles, [Stockfish SFR
357.6027.2]. This album highlights the
artist’s folk/blues vocals and lyrics and
his beautiful acoustic guitar work. On track
#6 “Fender Bender”, Jones and bassist,
Grischka Zepf, engage in an up-tempo
instrumental played, for the most part, in
unison. The AMR allowed me to more easily
differentiate the two guitars. The CD-77's
quicker transient attacks and tonal purity
markedly improved my appreciation and
enjoyment of this fine disc. This effect was
partially attributable to the AMR’s superior
bass performance that allowed the midrange
to sing without competition from the lower
frequencies.
 The
CD-77's upper frequencies are extended,
clean and crisp with no glare or unnatural
edge. This was evident with the massed
strings on Track #1, “Hedwig’s Theme” on
John Williams’ soundtrack from Harry Potter
and the Prisoner of Azkaban [Nonesuch
7567-83711-5]. The CD-77 struck that
difficult balance of resolution, clarity and
detail without sounding strident or edgy.
The strings were airy and rich with superb
image and focus. Yet with all the busyness
of this soundtrack, everything was coherent
and of a piece. No desultory presentation
here. Small scale acoustic music was equally
well served. London-born signer-songwriter
Alexi Murdoch’s impressive new album, Time
Without Consequence [2006 Zero Sum Records],
is a combination of expressive and
introspective lyrics and moody guitar work.
His vocals and strings on “Breathe” were
rendered with intimacy, delicacy and rich
tonal color.
Image stability, resolution and
transparency, were all strong suits of the
CD-77. Its leading edge and trailing
transients are quick and true to life - no
exaggerated, hyper-detailed leading edge to
give the false impression of
ultra-resolution. I never suffered listener
fatigue regardless of the volume or length
of listening session. The AMR’s soundstage
width was very good - slightly wider than
the Reimyo’s - while soundstage depth was
commensurate with real music. Dynamically,
the CD-77 can go from subtle to explosive
and back without batting a sonic eyelash.
Micro and macro dynamics are reproduced with
equal aplomb. It accomplishes this feat with
finesse and an effortlessness that belies
its dynamic excellence. However,
notwithstanding all of these outstanding
individual characteristics, the AMR’s most
impressive attribute is the sonic portrait
it paints as a whole – a “whole” greater
than the sum of its impressive parts. What
the CD-77 does best is what it doesn’t do -
it never calls attention to itself in any
one area. Instead, like a good story teller,
it keeps drawing you further and further
into the experience literally preventing you
from critical analysis.
I’d be remiss if I didn’t discuss one of the
most unique attributes of this excellent
player - its adjustability. As mentioned
above, the CD-77 has six different sampling
settings allowing the user to select from
among the settings “on-the-fly”. While I did
experiment with all of the settings, I
always came back to the Digital Master II
mode (the mode suggested by AMR). All of my
listening impressions in this review were in
this mode. The Digital Master I mode is
devoid of any filtering at all. AMR
acknowledges that: “Due to the complete
lack of digital or analogue filtering, the
treble frequencies are slightly rolled off,
making the sound somewhat soft and laid-back
… This mode often helps to ‘tame’
overly-bright recordings.” As mentioned
above, AMR recommends using Digital Master
II which is identical to Digital Master I
but with a special analogue filter to
correct the treble roll-off. I found this
mode to produce the most airy, transparent,
realistic, non-digital sound. The other four
modes, Oversampling 2x, Oversampling 4x,
Upsampling at 96 kHz, and Upsampling at 192
kHz, include digital filtering or upsampling
allowing the user to modify the sound to
meet his/her preferences. In my system, the
Digital Master I mode sounded too rich and
rolled off. Conversely, the oversampling and
upsampling modes produced a “perceived”
increase in detail and dynamics but at the
cost of sounding more unnatural, grainy and
edgy (read: “digital”) on all but the worst
recorded discs. Not all CDs or systems are
created equal and some may benefit from such
a sonic band-aid. Whatever your reason for
using them, a CD-77 owner can’t help but
appreciate the flexibility the various modes
provide.
Finally, if you haven’t noticed by now, the
CD-77, which retails at $8,500.00, bettered
my reference Reimyo CD-777 which retailed at
exactly double that ($17,000) when it was
last sold. Save for the Meridian G08, every
other digital front end the CD-77 outclassed
in my system cost thousands of dollars more
than the AMR. While $8,500.00 is not exactly
chump change, considering its competition,
the AMR is as close to an audio “steal” as
you can get.
Down sides? Even the fat lady has flaws
right? Yes and no. I did experience a very
intermittent problem with the CD-77. About
once a month on certain discs, the CD-77
either failed to read a disc or, when
playback began, emitted an annoying static
sound. Most of the time, this problem was
easily corrected by opening the drawer and
re-seating the disc and puck. However, on a
couple of my discs (out of hundreds I’ve
played on it) the CD-77 simply failed to
read them - while the Reimyo had no problem
reading the same disc. Such an intermittent
problem can be very difficult to re-create
and, thus, correct. Thankfully, through
AMR’s persistent and diligent efforts, I am
informed they have isolated the problem and
addressed it. The CD-77 also runs hot and
does contain tubes that will ultimately need
to be replaced. Fortunately, this shouldn’t
be necessary for thousands of hours under
normal operating conditions. While I know no
component is perfect, in my system I just
couldn’t find any noticeable sonic
shortcoming in this excellent player. If
that makes me a shill, too easily pleased,
or a hearing impaired reviewer, so be it.
With the AMR CD-77 driving my system, I
never felt I was missing anything or wanted
for anything more except music.
Curtain Call
I admit I’ve not heard every CD player
available. I also have no aversion to “new
school” digital technology and look forward
to hearing hard-drive or memory based source
components in this world of accelerating
digital advancements. However, whether it’s
“old school” or “new school”, when a
component allows me to easily analyze and
describe its characteristics - be they warts
or strengths - it’s usually because the
component is flawed, unnatural or calls
attention to itself in a non-musical or
artificial way. Whatever the reason, such a
component directs the listener to its
“sound” rather than to the music. The AMR
CD-77 was the antithesis of such a component
- the more I tried to concentrate on the
sound, the more I found myself unable to do
anything but tap my foot, sing along and
play air guitar! To put it succinctly, for
what I was commissioned to do (critically
analyze it), it was a reviewer’s nightmare
and a music lover’s dream. So I did what any
music lover would do - I purchased it! What
higher recommendation can I give?
Dear Stereo Times,
We thank you for a most thorough and
eloquent review of the CD-77. The effort was
certainly apparent and very much
appreciated.
We were especially moved by the fact that
you understood the heart of the CD-77 and
what it means to us.
In addition, we would like to thank Mr Frank
Peraino for allowing us to analyze his three
problem disks. We found individual pressing
faults had caused the problems.
Many thanks again.
Staff and Directors at Abbingdon Music
Research
Specifications:
Type: Single-box CD player
Input: 1x USB
Outputs: 1pr single-ended phono
1 pr balanced XLR
Output Level: 2V
Tube Complement: 2x ECC81
2x 5687 and 2x 6CA4 (NOS)
Dimensions (WxHxD): 460 x 160 x 470mm
Available Finishes: Champagne or titanium
Weight: 28kg
Guarantee: 5 years
Price: $8,500
U.S. Distributor:
Avatar Acoustics
Website:
http://www.avataracoustics.com
Manufacturer:
Abbingdon Music Research
Website:
http://www.amr-audio.co.uk
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