Used DCS Puccini U-Clock, rarely seen for sale separately from the DCS Puccini CD/SACD players. Amazing upgrade,when used with any DAC with word clock input, the unit reduces jitter and allows for a more natural and flowing presentation from your favorite digital based music collection. I used it with the DCS Debussy and the change in overall presentation, timbre, soundstage and air around instruments and voices was undeniable. The unit works flawlessly 10/10 but cosmetically, their is a small "nick" in the aluminum front panel fascia, which can be seen in the actual photographs posted above hence the 7/10 rating. Included is the original DCS factory box, manual, cables, including USB cable and packaging.

dCS Puccini CD/SACD Player and Puccini U-Clock USB Converter/Clock (TAS 200)

by
Robert Harley

|
Jun 04th, 2010

Categories:
Disc players,

Digital-to-analog converters


|
Products:
dCS Puccini

I’ve lived with quite a few of the most ambitious digital-playback
products in my twenty-one years as a full-time reviewer, but somehow
never managed to audition a unit from England’s Data Conversion Systems
(dCS) until now. That’s a shame, because the dCS Puccini CD/SACD player
and U-Clock combination has turned out to be one of the world’s great
digital front ends.

The company dCS has a long history of technical accomplishments in both
professional and consumer audio. The firm pioneered many cutting-edge
advancements, including the proprietary “Ring” DAC
found in all its digital-to-analog converters (see sidebar). Mike
Story, dCS’s founder, was also at the forefront of high-resolution
digital audio long before it was a commercial reality. I attended a
paper he presented at an Audio Engineering Society convention in the
early 1990s in which he correctly posited that the sonic improvement
rendered by high sampling rates was the result of improved time-domain
performance due to the relaxed filter requirements. That’s accepted
wisdom today, but it was revolutionary nearly twenty years ago. Over the
decades dCS has addressed such topics as upsampling, PCM-to-DSD
conversion, jitter, noise-shaping, the time-domain performance of
digital filters, and other issues long before they became part of the
high-end mainstream.

dCS is again taking the technology lead with the U-Clock, a device that
vaults the sound of the company’s Puccini CD/SACD player into new sonic
territory while simultaneously expanding its functionality to
incorporate state-of-the-art decoding of high-resolution digital audio
from a PC-based music server.

The $17,999 Puccini player is the same model Jonathan Valin commented on
in his review of the Scarlatti, dCS’s $67,000 three-box statement
product (Issue 183). Jonathan concluded that the Scarlatti was the best
digital he’d heard, an opinion apparently shared by quite a few high-end
manufacturers judging from the number who have purchased the Scarlatti
for their own development work or trade-show demonstration. Jonathan
also thought that the less-than-third-the-price Puccini was very nearly
as good as the reference-quality Scarlatti.

The
$4999 U-Clock improves the Puccini’s sound quality by delivering an
ultra-precise clock to the player, reducing jitter. As has become
abundantly apparent, great-sounding digital audio requires
extraordinarily precise timing in the conversion of digital data to an
analog waveform. My review of the $16,000 Esoteric G-0Rb rubidium clock
(Issue 180) created skepticism among certain readers that human ears can
detect timing variations that are measured in picoseconds (see, for
example, the letter from Dave Martson in Issue 198). The objections to
expensive outboard clocks are not based on these readers’ own listening
experience, but purely on theoretical grounds—conventional clocks should
be good enough, in their view. But there’s a simple way to determine
for yourself if jitter is a factor in digital audio reproduction—listen
to a Puccini with and without the U-Clock engaged. As we’ll see in the
report on my listening impressions below, the difference is not subtle.

The U-Clock’s second important function is to allow the Puccini CD/SACD
player to operate as a digital-to-analog converter for PC-based music
servers that have a USB output. The U-Clock takes in digital audio data from a PC on the USB
interface and converts it to S/PDIF for presentation to the Puccini.
That might not sound like a big deal—one can buy a box for $250 that
does the same thing—but dCS has engineered a state-of-the-art USB interface that introduces absolutely no sonic compromises. Rather than considering USB a limiting factor in PC-based audio sound quality, dCS believes USB is the optimum interface if engineered correctly.

In most digital interfaces, including S/PDIF, AES/EBU
(a variant of S/PDIF), and FireWire, the source component (the CD
transport or PC music server, for examples) is the master clock to which
the receiving device must lock. Virtually all USB DACs
operate in this way, which is known as “Adaptive Mode.” Asking the
receiving device to lock to the source’s clock is problematic for
several reasons. Although the USB interface
was never designed for transmitting high-quality audio, it inherently
has the ability to allow the receiving device to control the data rate
from the source device—a feature not possible with S/PDIF, AES/EBU, or even FireWire.

dCS has developed its own technology for exploiting USB’s
built-in “feedback” system which allows its own high-precision clock to
serve as the master, forcing the source (the PC-based music server) to
slave to that clock. This technique, called “Asynchronous Mode,”
transforms the USB interface into a
high-quality interface. Rather than the computer establishing the clock
precision (not a good idea for many reasons), the entire audio system is
clocked by a high-precision crystal inside the U-Clock. Note that an
asynchronous USB interface doesn’t automatically confer low-jitter and better sound; it still must be implemented with a high-quality circuit.

Moreover, locating this asynchronous USB interface in a separate chassis (the U-Clock) rather than in the DAC itself has many benefits. First, noise in the PC is isolated from the DAC by the U-Clock. Second, the DAC
needn’t incorporate another clock running at a frequency unrelated to
the audio-based clocks. Multiple clocks running at different frequencies
within the same chassis can introduce cross-contamination.

The
U-Clock is an apparently simple, yet brilliant, solution to adapting a
CD player (the Puccini) to the needs of music-server owners. It solves
sonic compromises of the USB interface with
state-of-the-art design and implementation in a separate chassis, as
well as allowing music-server users to decode files through the
Puccini’s outstanding DACs.

Although Jonathan covered the Puccini as a CD player in his review,
let’s recap the machine’s highlights. The unit is simply stunning
visually, with gracious curves and an unusual surface pattern etched
into the shiny aluminum front panel. My only complaint is that the
front-panel button markings are small and hard to read, a problem that
diminished with familiarity. The drawer mechanism of the
Esoteric-sourced transport is all-metal and operates silently and
smoothly. A front-panel display allows the user access to a wide range
of controls through an extensive menu system. One of these controls
allows the user to select whether and how the signal is upsampled. One
option is to convert any resolution PCM (from CD or files from a music server) to DSD before decoding (the other option is PCM-to-PCM upsampling). I found that the PCM-to-DSD
conversion sounded the best, and this was the option I used for nearly
all my auditioning. The display shows the clocking status via a clever
icon of two gears meshing. The Puccini will decode 44.1kHz, 48kHz,
88.2kHz, or 96kHz, all with up to 24-bit word length. Note that it will
not decode 176.4kHz (such as Reference Recordings HRx files) or 192kHz.

The rear panel offers both balanced and unbalanced outputs, along with digital inputs and outputs (two each on RCA jacks). A BNC
connector accepts the clock signal from the U-Clock. The Puccini has a
variable output, enabling it to drive a power amplifier directly. You
can select a maximum output level of 2V or 6V; I recommend the 2V
setting if you are driving a preamplifier.

The U-Clock matches the Puccini visually, and the two look stunning
together. The front panel has just two pushbuttons and three LEDs. The
leftmost button and accompanying LED is
intriguing, to say the least. Marked “Dither,” it modulates the clock
edges in a controlled way in an effort to improve sound quality. It’s
counterintuitive that changing the timing of the clock edges could make
the Puccini sound better, but dCS found that this small variation
“exercises” the PLL in the Puccini and results in better sound. The modulation is easily filtered by the PLL.
You can judge for yourself simply by turning dither on and off. The
second button selects the clock frequency, either 44.1kHz (used for
44.1kHz sources and multiples of 44.1kHz, including SACD) and 48kHz (for 48kHz and 96kHz sources).

Listening

I started by listening to the Puccini as a CD and SACD
player without benefit of the U-Clock. It was immediately apparent that
this was one serious contender for the best digital I’d heard. The
sound was immensely appealing, particularly the gorgeous, liquid, and
glare-free midrange. The presentation was a bit set-back rather than
forward, with tremendous depth, clarity, and transparency. There was
also an intangible sense of sonic coherence that manifested itself as a
kind of “musical rightness.” Whatever the Puccini was doing, it was
different from other great digital I’ve heard.

After getting a general impression of the Puccini itself, I engaged the
U-Clock. One little front-panel button-push vaulted what was already a
spectacular sound into entirely new territory. The U-Clock snapped
images into sharp(er) focus, increasing the sense of clarity, precision,
and definition I had enjoyed from the Puccini alone. The heightened
focus had a profound effect on the sense of instruments existing within
an acoustic. Without the U-Clock, reverberation tended to be connected
to the image itself, as though the image and the hall were merely
variations of the same sonic cloth. With the U-Clock, the instrumental
image was presented as a clearly defined object existing within an
acoustic space rather than simply fused to it. The instrument and the
surrounding acoustic were presented in a closer facsimile to what we
hear it in life.

That was just the beginning of the U-Clock’s magic. The Puccini’s
reproduction of timbre, which already had a bell-like clarity, was taken
to a new level by the U-Clock. Timbres had greater palpability and
realism, partly the result of less grain and edge (which were already
very low) and partly because of greater resolution of textural detail.
Similarly, the U-Clock made the Puccini’s reproduction of transient
information even more lifelike. The leading edges of piano attacks, for
example, had a trace of edge that vanished with the U-Clock engaged.
Listen, for example, to the wonderful new recording of Vassily Primakov
performing Chopin mazurkas on Bridge Records. The U-Clock made the piano
more lifelike in transient attack, in richness of tone color, and
particularly, in the sense of space surrounding the instrument. I pulled
out this CD as a diagnostic tool to listen for specific sonic
attributes of the U-Clock but immediately forgot about the sound and
listened to the entire disc, completely captivated by the compositions
and Primakov’s expressive performance. Such an experience is always the
sign of a great component.

In short, if you own a Puccini the $4999 U-Clock is an essential upgrade.

The Puccini/U-Clock combination was “plug ’n’ play” with regard to the USB interface. I connected a generic USB
cable from my fan-less, drive-less PC server to the U-Clock, selected
the appropriate input on the Puccini, and the system played back my
music files at a variety of sampling rates. I listened to files at
44.1kHz, 88.2kHz, and 96kHz from the server, as well as CDs and SACDs played in the Puccini’s transport.

Getting back to the sound of the Puccini/U-Clock combination, I found
myself consistently and deeply engaged with the music. The dCS pair had a
different presentation than I’ve heard before from digital that is
difficult to describe. The Puccini/U-Clock was distinguished by a
pristine clarity of timbre along with a crystalline-like transparency of
soundstage. It simply lacked the artifacts we associate with digital,
such as a synthetic gray pall overlaying tone colors, grain and glare
embedded in timbres, and a sense of haze or opacity between you and the
music. Instruments and voices were vivid and alive, yet the presentation
was never forward. In fact, the sound was relaxed and engaging despite
the sense of immediacy. Background vocals were revelatory in that I
could clearly hear the timbres of individual voices and how they blended
into each other. I was also struck by the sheer realism of Neil Young’s
guitar on some 96kHz/24-bit tracks from Harvest sourced from the music
server; it had more “guitarness” and less of a mechanical sound than
I’ve heard from this track before. I got the impression of greater
density of information, but not in an analytical way. I’ve heard a
number of digital products that sound very clean, precise, and
transparent, but those qualities are often accompanied by a mechanical
character, a coldness or a stark sterility that doesn’t foster musically
intimacy. The Puccini/U-Clock’s central triumph was the ability to
sound super-pristine and precise, yet simultaneously warm and involving.

An analogy that came to mind to describe the Puccini/U-Clock’s density
of tone color and liquidity of timbre is of two identically colored bed
sheets, one made from 600-thread-count cotton and the second made from
400-thread-count material. Put the 400-count sheet through the wash a
few times and leave it in the sun for a day. Now compare the two sheets.
The 600-thread-count sheet is finer in texture, smoother, and more
continuous. It’s also more richly hued and vibrant. The Puccini’s
rendering of instrumental timbre is like that of the 600-thread-count
sheet, while most other digital is analogous to the 400-thread-count
sheet.

In addition to this remarkably naturalistic rendering of timbre, the
Puccini threw a stunning sense of space and depth, revealing the size of
the hall and the spatial relationships between instruments. In
addition, the background was jet-black which further highlighted the
sense of image tangibility. The pair’s exceptional low-level resolution
contributed to expansive sound as fine spatial cues in the back of the
soundstage were rendered with great clarity. Reverberation decay was
stunning in the way it maintained resolution down to the lowest levels,
the smoothness of the decay, and the way it seemed to hang in space.
This is one area where state-of-the-art modern digital is vastly better
than earlier efforts, which truncated reverberation decay and sounded
coarser and coarser at lower and lower levels.

I found the Puccini/U-Clock highly involving rhythmically. The bass was
extremely punchy and dynamic, with a very tight and controlled quality. I
heard a dynamic coherence from top-to-bottom, as though the music
“gelled,” heightening the feeling of musicians locking into a groove.

There’s one area in which the Puccini/U-Clock significantly distances
itself from all competition, and that is in the reproduction of very
fine high-frequency transient detail. I was floored by the Puccini’s
resolution of micro-detail—think brushes on cymbals, shakers, the zils
on a tambourine, gently struck triangles, and güiro. The lower the level
and the more transient the nature of the signal, the greater the extent
to which the Puccini outshone other digital I’ve heard. Information
that was simply blurred by other digital was resolved with pristine and
vivid clarity by the Puccini. For example, the triangle on
Rachmaninoff’s Symphonic Dances had a delicacy that vividly conveyed the
mechanism by which the sound was made. It wasn’t just a high-frequency
transient, but a pitch accompanied by a strong sense of attack, ringing,
and decay. But the track that most dramatically illustrated the
Puccini’s unmatched performance in this area is the beginning of
“Valentino“ by Victor Feldman on the JVC XRCD
title Audiophile (a compilation of two records made in the 1980s,
engineered by the great Alan Sides). The track starts with a rain stick
behind Hubert Laws’ gentle flute passage. I’ve listened to this track
countless times over the years, but have never heard the individual
beads moving through the rain stick with such startling clarity. I point
this out not because I enjoyed this quality for its own sake, but
rather to illustrate how the Puccini accurately conveyed very fine
transient detail, and how this fidelity fostered a sense of hearing the
instrument itself rather than a reproduction of it.

It occurred to me that one reason the Puccini/U-Clock rendered timbres
with such realism could be this fabulous resolution of low-level detail,
particularly low-level transients. Musical waveforms contain a richness
of micro-dynamic structure (a reed moving back and forth, for example);
accurately conveying that structure makes instrumental textures and
tone colors more lifelike. Although we’re not consciously aware that the
timbral realism is derived from this micro-transient information, it’s
simply one less cue to the brain that we’re hearing a reproduction
rather than the instrument itself.

Although I don’t have nearly as much experience with cutting-edge SACD playback as I have with CD, I thought the Puccini/U-Clock’s rendering of SACD
was the best I’ve heard. Interestingly, however, the Puccini/U-Clock’s
reproduction of CD was so good that it narrowed the gap I usually hear
between CD and SACD.

Finally, you’re probably wondering how the Puccini/U-Clock compares with
the other great digital I’ve heard lately, including the Meridian 808.2
and Spectral SDR-4000 Pro CD players, as well as the Berkeley Alpha DAC. Starting with the Alpha DAC,
the Berkeley unit was a bit more forward in spatial presentation,
presenting the front of the soundstage a little closer to the listener.
The Puccini’s bass was leaner and tighter, with the Alpha DAC sounding “bigger” in the bottom end but somewhat less controlled. The Alpha DAC
excelled at macro-dynamics with greater impact on timpani strokes, and
also with a warmer and fuller rendering of bass guitar. As great as the
Alpha DAC is, the Puccini/U-Clock combination
bested it overall with a smoother rendering of midrange textures, a
heightened sense of space, and, particularly, the resolution of
transient detail. The Alpha DAC was at a disadvantage in the comparisons in that it was fed from the same music server as the Puccini, but through an AES/EBU
interface rather than through the U-Clock that locked the computer to
its timing reference. Also, keep in mind that these are two very
different products; the Alpha DAC will decode up to 192kHz sources and has no USB input, disc drive, or SACD capability, but costs less than one-quarter the Puccini/U-Clock’s price.

The other contenders for the state-of-the-art in digital playback (at least in my experience), the Meridian 808.2 and Spectral SDR-4000
Pro, make an interesting contrast with the Puccini/U-Clock. The
Spectral and dCS better the Meridian in resolution of low-level detail,
transient fidelity, and bass definition. But the Meridian excels,
uniquely, in its portrayal of dimensionality—the impression of
three-dimensional instruments in three-dimensional space. The 808.2 is
also remarkable in its reduction of hardness and glare, particularly in
poor-sounding CDs. The Spectral’s strengths are in its portrayal of
soundstage depth and resolution of fine spatial and timbral detail. I
thought the Puccini/U-Clock rendered midrange textures with greater
warmth and palpability. All four products have their own virtues, and
all are contenders for the state of the art.

Finally, you really need to hear the Puccini/U-Clock driving a power
amplifier directly to fully appreciate its clarity and resolving power.
Even the best preamplifiers shave off some detail and diminish the sense
of immediacy and transparency that are the Puccini’s hallmarks.

Conclusion

The dCS Puccini/U-Clock pair is an extremely sophisticated piece of
engineering. Rather than working within the limitations of off-the-shelf
technology, dCS has developed a number of innovative and advanced
technologies to extract the maximum performance from digital media. That
effort has paid off in the listening room—the Puccini/U-Clock delivers
an enormously appealing and involving musical presentation that is in
many ways competitive with the state of the art, and in some aspects
establishes a reference-quality level of performance.

The dCS’ sound was different from other top contenders I’ve heard, and I
struggled to put that difference, and its effect on musical
involvement, into words. But if I had to boil it down to a single idea,
it would be that the Puccini/U-Clock simply presents more musical
information to the listener without calling attention to the fact that
it’s presenting more information.

I can’t overstate how much I enjoyed music through the Puccini/U-Clock; it was absolutely enthralling on CD, SACD, and high-resolution sources. This is a digital front-end I could live with for the rest of my life.

______

Sidebar: Under The Hood

The Puccini features an Esoteric transport mechanism (with a custom
drawer) under dCS’s custom-software control. In fact, all the software
inside the unit is written by dCS. This software can be updated by
downloading new code distributed by dCS on a CD. The custom digital
filter is implemented in two DSP chips and two
field-programmable gate arrays. Four filter types are available,
selectable from the front-panel menu system. Filter 1 has the widest
bandwidth and is the recommended setting. Filters 2 and 3 roll off at
progressively lower frequencies. Filter 4 is the “measurement” filter,
and isn’t intended for listening. The filter choice affects the amount
of out-of-band noise allowed through the system. All the filters are FIR linear-phase types.

When you select PCM-to-PCM upconversion on the front panel, the digital filter feeds a modulator that converts the PCM data to the 5-bit format required by the Ring DAC. If you select PCM-to-DSD upconversion, the filter’s output goes through an additional step of converting PCM to DSD before the modulator that creates the 5-bit Ring DAC code.

The Puccini features exactly the same Ring DAC found in the $67,000 Scarlatti. This DAC,
developed by dCS in 1992 and under refinement since, completely
eliminates a source of distortion in conventional off-the-shelf DAC chips. It is implemented with 20 discrete devices per channel. Its fundamental nature lends itself to converting DSD
signals, which is one reason why the Puccini sounds the best in this
upconverting mode. (For a cogent explanation of how the Ring DAC works, see Jonathan Valin’s sidebar on page 109 of Issue 183.) The Ring DAC’s balanced output feeds a fully discrete Class A output amplifier. This is the signal that appears on the XLR
jacks. The single-ended signal is buffered by an op-amp-based circuit
so that output levels are consistent between the balanced and
single-ended outputs (a balanced circuit inherently is 6dB higher in
level). The power supply is a hybrid of switching and linear supplies
that was newly developed from scratch for this latest generation of
products.

The Puccini is a very advanced product, both in its design and
capabilities for the user. Note, however, that the Puccini requires
greater owner involvement than other CD players with its selectable
upsampling, selectable filters, upgradable software, and extensive menu
system.

______

JV Comments:

Well, I was supposed to write a sidebar comment to this review, but what
can I say that Robert hasn’t already said better in this brilliantly
worded and precisely accurate assessment?

I was very curious to see how my best friend and colleague in this
industry would react to the Puccini, since he has so much more
experience with the finest digital front ends than I do (and than
virtually anyone else in this business does). Don’t take it as vanity on
my part if I say I am delighted that he heard the Puccini as I do. It’s
not ego, believe me; it’s relief. When I reviewed the Scarlatti/Puccini
several moons ago, I thought both were “the best digital” I’d heard,
but I thought this for a very specific reason and, let me add again, I
thought this without having the vast comparative experience that Robert
has with digital sources. My reason for loving the Scarlatti and Puccini
was that both sounded like analog sources without sacrificing digital
virtues. By sounding like analog sources I don’t mean they made CDs
sound like LPs, exactly. I mean that they shared with record and tape
players a more “holistic” presentation than digital typically provides.

To my ear, digital has always sounded—to greater or lesser extents—flat in aspect and piecemeal in presentation. CD and SACD
present the trees, all right, right down to the veins in the leaves,
but they invariably seem to lose sight of the scope, spaciousness, and
sheer volume of the forest. It’s not that CDs and SACDs
aren’t often sonically impressive—and lifelike. LPs do not typically
have the extension and dynamic impact of CD/SACDs, particularly in the
bottom octaves; nor do they typically have the sheer crystalline clarity
of digital sources. But…digital sources do not have what analog (at its
best) has: a realistic warmth of timbre and richness of texture
inextricably coupled with a lifelike bloom and body that make
instruments and vocalists seem three-dimensionally “there”—perhaps a bit
less “look-at-me” detailed than digital but more rooted, more present,
more complete, more real. CDs and SACDs make
musicians sound the way highly detailed photographs look; LPs and tapes
make musicians sound the way statues in a statue garden look.

With the dCS Puccini and the Scarlatti par excellence, this changed. The
details they were adding didn’t just amount to hearing, oh, three more
second violins more distinctly in the string section (although you could
hear three more second violins more distinctly); rather, I was hearing
the whole string section (and each violin in it) with a new-found
fullness of timbre and texture and an unparalleled (in the digital
realm) three-dimensionality and ambient clarity. The dCS’s details
didn’t stand out as individual parts; instead, the parts it was adding
were making more complete wholes. Robert put this better than I did when
he said that the Puccini “simply presents more musical information to
the listener without calling attention to the fact that it’s presenting
more information.” This is precisely correct.

With the addition of the U-Clock, the gap between the Puccini and the
Scarlatti (which has its own clock) has narrowed. Robert once described
the way timing errors (jitter) affect digital sound by analogizing an
unclocked or poorly clocked CD player to hand-held binoculars—with their
inevitable image blur caused by the shaking of your hands—and a
precisely clocked CD player to image-stablilizer binoculars—which
“freeze” what you’re looking at, as if you’ve taken a jitter-free
picture of it. Once again, I can’t improve on this. This is exactly the
difference that I heard with the U-Clock. What was a bit fuzzy—almost
literally “jittery”—snapped into focus.

To an extent the U-Clock gives you the best of both the digital and
analog worlds: increased (because better focused/timed) detail, and
increased (because better focused/timed) wholes. The U-Clock is a
no-brainer recommendation, as is the Puccini itself.

SPECS & PRICING

Puccini CD/SACD player/DAC
Conversion: dCS Ring DAC
Sampling frequencies: Up to 96kHz/24-bit
Inputs: S/PDIF (x2) on RCA, clock on BNC
Outputs: S/PDIF (x2), balanced analog on XLR, unbalanced analog on RCA
Dimensions: 18.1” x 4.4” x 15.8”
Weight: 26.6 lbs.
Price: $17,999

U-Clock
Outputs: Clock signal on BNC (x4), S/PDIF on RCA (x2)
Inputs: USB
Dimensions: 18.1” x 2.3” x 16.1”
Weight: 16.7 lbs.
Price: $4999

DCS NORTH AMERICA

3057 Nutley Street

Fairfax, VA 22031

(617) 314-9296
dcsltd.co.uk