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47 Laboratory 4704 PiTracer CD Transport and 4705-G Gemini Progression DAC Review

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47 Laboratory 4704 PiTracer CD Transport

The Mind Behind The Machine

In the article, “Designing the PiTracer”, Junji detailed his R&D process in the early 90’s, in search of an ultimate CD transport design that would yield superior data retrieval rate with the most uncontaminated signal relay. Having background in circuit simplification and mechanical /structural refinement (see Flatfish Review), one of Junji’s first tasks was to tackle conventional mechanisms’ intrinsic vibrations which he deemed as detrimental to any player’s performance, in the forms of the moving parts of spindle motor and laser pickup.

The ultimate expression of Junji’s ideal came in the form of a linear-tracking vinyl turntable, in the segregation of the laser pickup and platform. The PiTracer’s laser assembly is embedded into an unusually massive, 1.5 kilogram, vibration-dampening aluminum head mechanismhovering above the CD platform.

Incorporating no less than a frontward LCD display and skyward control buttons, the PiTracer’s massive block of aluminum is the focal point of the entire design. The originality of the hovering superstructure concept liberated Junji from using industry-standard designs on laser pickup arrangement, thus accorded him the freedom of creating an industry-first method that read the CD pits stringently at a 90 degree angle to ensure maximum image reflections over rampant pit irregularities.

On designing the PiTracer’s platform, Junji even adopted the vinyl turntable’s 1:100 mass ratio between platter and base into his design, hence the PiTracer’s armament of a featherweight, 90-gram, acrylic platter fitted to a platform machined out of a solid block of aluminum weighing over 9 kilograms. An equally lightweight, acrylic disc clamp is to flatten and secure the disc.

The CD platter is propelled directly by a high-torque motor underneath, and an encased second spindle motor is visibly situated in the front corner of the PiTracer platform, driving a system of Kevlar thread and warm gear that pulls the hovering platform via premium, industrial bearings and rails. The miniature rails and wheels, made by Bishop-Wisecarver (, a California company that pioneered guide wheel technology, are the most gem-like and their interactions among the smoothest I’ve seen.

It is noteworthy that consistent with his other designs, the PiTracer is so idiosyncratic in design that the significance and wisdom of an environmentally isolated disc chamber is all but abolished in the PiTracer. To my knowledge, the 47 Laboratory’s top-of-the-line CD transport was the first and only of its kind featuring an unorthodox platform and laser pickup system, placing the disc content side up onto a platform and spun by a high-torque, coreless motor below.

System Details

Two system configurations were used to evaluate the PiTracer. One of the systems was consisted of the Audio Note DAC 5 Special ($30,000), the Harmonix Reimyo CAT-777 preamplifier ($17,000), the PAT-777 300B amplifier ($27,000) and the Audio Note AN-E SEC Silver loudspeakers ($20,000).

The other system assembled was consisted of 47 Lab’s entire suite of electronics, namely the company’s latest $7,100 4705-G Gemini Progression DAC and a custom 4707 Gaincard S, costing a coincidental $7,100 as well. Tannoy’s $19,500 Churchill Wideband loudspeakers served in this configuration.

In this system, all 47 Lab equipment utilize segregated power supplies, and each equipment used in this review is equipped with two umbilical power cords for connection with the original power supply, which has two-ports for accepting the umbilical cords. The PiTracer’s two cords are for powering the platter and head mechanism separately, while those in the Gemini Progression and Gaincard S are for the left and right channels.

For this review, a uniform, dual-mono power supply arrangement using two power supplies was adopted for each equipment to achieve its best. Consequently, two Power Humpty’s were arranged to separately power the PiTracer’s platform motors and head mechanism, another two higher-power Power Humpty S’s were for the Gaincard’s two channels and two Power Dumpty’s for each of the Gemini Progression’s 2 channels.

All six power supplies were plugged directly into AC outlets running on dedicated lines from the circuit breaker, and to save space, all of them were placed faced down and standing tall on the carpet behind the two Salamander Design racks.

Cabling were of Audio Note throughout, specifically a 1 meter RCA run of the Sogon as digital cable, a 2 meter RCA pair of Sogon as interconnects and a pair of 2 meter banana-terminated bi-wiring AN-SPx speaker cables. Two Harmonix Reimyo’s Studio Master AC cord in 5-foot length and two similar length of Granite Audio’s #560 AC Mains were also used to varying effects. The CD transport benefited marginally from either the Harmonix Reimyo power cords or the Granite Audio power cords; but the Gaincard S attained a higher level of performance with the HR cords. Therefore, in the context of the 47 Lab suite, the GA cords powered the PiTracer, while the HR cords powered the Gaincard S.

Tracing Pits

The PiTracer arrived in a period when I had already been using Audio Note’s $30,000 DAC 5 Special “Super DAC” for some time, and review of which was subsequently posted onto Stereo Times when I was writing as one of its Senior Editors. Audio Note recently upgraded my DAC 5 Special, and a follow-up review is in the works.Among the outstanding transports I have had the good fortune of using, such as, in chronological order, the CEC TL1 belt-drive CD transport, and Sony SCD-777ES SACD player and 47 Lab’s own Flatfish, the vitality of the DAC 5 Special in its superb tonal contrast and vividness was most appreciable via the Flatfish. Yet, the twin Power Humpty’s-supported PiTracer invoked from within the Super DAC an even richer portal of sonics of such immensely convincing qualities that the descriptive “genuine” was as befitting as it was literal.

For example, from the 1983 Philips disc of Edvard Grieg’s Peer Gynt incidental music excerpts (Philips 411 038-2), while the wondrously resolving Flatfish enabled the Super DAC to project soprano Elly Ameling’s graceful, evocative voice with distinct tonal shading and dynamic scaling in “Arabian Dance”, the coaxial-linked PiTracer brought to the table an even higher level of the Flatfish’s resolution, distilling clearer, farther degrees of the interplaying tonalities and dynamics.

The PiTracer’s discreet reading of Dame Ameling’s intonation in “Solveig’s Song” and “Solveig’s Lullaby” was the most compelling for the first time in narrating the heart wrenching perseverance of a virtuous love far away. The transport also harnessed surprising dynamics from the San Francisco Symphony’s rousing procession‘s beginning pianissimo in “In the Hall of the Mountain King”, to the magnificence of the concluding fortissimo.

Hence, making way for a sound that bore acute witness to what I was contending with before, the PiTracer prompted realization of the varying degrees of persisting ambiguity and irresolution all transports before it were never freed from. It boggles the mind of what the PiTracer was able to uncover in a 1983 release, instilling farther refinement beyond the purity of the Flatfish.

Tonal distinction ability of the PiTracer became more appreciable when playing audiophile CD’s, such as the Jheena Lodwick 24 bit Super Analog XRCD24 disc All My Loving…(JVC XRCD24-1007SA), from which the transport delineated Ms. Lodwick’s saccharine vocal spotlessly in the midst of instruments. In spite of the modesty of scale, this recording sounded more radiant and ravishing in the care of the PiTracer, conjuring up convincingly expressive dynamics and agile transients.

The 47 Lab transport also uncovered the potentials of RBCD layer in hybrid SACDs, such as in the Deutsche Grammophon’s 2002 release of Mahler’s Das Lied von der Erde (SACD 471 635-2).

When coupled to the AN Super DAC, the transport invoked defining, lofty range of instrumental transients from within the Mahler Lieder amidst eminently contrasted vocals. Set in the composer’s own, irresistible tonal canvas and orchestration, and using lyrics translated from eighth century Chinese poets, the emotional intensity embodied in Mahler’s lied+symphony creation was of a different league from his popular Titan and other symphonies from early stages in his life. The songs, in their ability to take avid Mahler listeners to exalted levels of revelation, showcased multi-faceted sonic depictions that were more intertwined than the colorsin a kaleidoscope, conveying what is probably the composer’s most poetic state of mind.

Being the most effective among DACs in my system, the Super DAC assisted in deciphering the differentiating dynamic characteristics of individual sounds while reconstructing an explicit soundstage, from the tenor and mezzo-soprano’s iteration of joys and sorrows of life to the Vienna Philharmonic’s stellar orchestral accompaniment. Yet, it was the PiTracer’s monumental provisioning of an indispensable and peerless platform, for the most subtle and yet expansive reconstruction of such data, that anchored the superiority of the CD playback system. Quite unnervingly, the SACD via the SCD-777ES sounded tonally less defined and spatially homogeneous in comparison.

On tracing an audiophile-class CD’s pits, the 47 Lab transport was the laboratory grade-equivalent of an instrument of precision. Instrument tonality of First Impression Music’s hybrid SACD, Antonio Vivaldi: The Four Seasons (FIM SACD 052) had astounding focus and body, demonstrating a tonal contrast the order of which made my Sony SACD player’s relatively inadequacy even more noticeable. Thus, in a steadfast recovery of the zero’s and one’s that constituted the Pietro Guarnei violin, circa 1722, the PiTracer’s liberated the treasured instrument’s sophisticated texturing and tonal shadings in the same way the violinist did with his sweeping technical finesse.

Likewise, St. Louis Symphony’s “Night On Bald Mountain” from Mobile Fidelity Sound Lab’s Mussorgsky: Pictures At An Exhibition (UDSACD 4004) hybrid SACD via the PiTracer sounded fresh and pristine, emerging with the most distinct timbre clarity and tonal separation ever. The violins were revealed to have contained the most delicate and explicit contrasts in dynamics ever from this CD, making the performance most spirited and surreal.

Error-Correction and Tracking

As all CDs are replete with varying degrees of data drop-out and off-centering during pressing, and the PiTracer emerged as the least tolerable of manufacturing defects among CD players I’ve used. It has superior tracking abilities on scratched discs; but is less appreciative of flawed discs.

About 10% of my cherished collection agitated the PiTracer enough to the extent that turntable-like skipping would occur during play. Ray Lombardi, a knowledgeable Audio Note user, was present during one session, and his instant response to it: “It’s all right, Constantine, we use turntables so we are used to that.” Worst scenario among the imperfect discs is the Teldec disc of Liszt’s Faust Symphony (Teldec 3984-22948-2), as the data drop-out rate of which, as seen by the PiTracer, was so severe that even a copied disc did not fare any better in playback.

On its superiority in reading scratched discs, despite the PiTracer’s intolerance of less perfect CDs, it actually managed to extract more of the sorely omitted notes than all other transports. Yoshi Segoshi of Sakura Systems, 47 Lab’s U.S. distributor, believes that adjustment to my PiTracer can be made to make it more tolerant of less-conforming discs. I shall follow-up with an update on any improvement on the factory re-adjusted PiTracer. So stay tuned.

G = Gemini

Non-over sampling, Digital-filter-less DAC Concept

A Cirrus Logic CS8412 IS chip adorns each of the two circuit boards housed inside the heavy, 2-piece aluminum chassis, and circuitries on both boards are part to part identical in reversed placements side by side. One power umbilical cord is assigned to each board and is directly soldered onto the related parts. Like the Progression, the Gemini supports only one RCA digital input and a pair of 2.1 volts, RCA analog outputs.

When rotated with different amplifications and speakers, the unifying sonic impression of the Gemini was one of lively swiftness: the sound of the Gemini expounds upon the dynamic transients of the lone Progression, showing incredible aptness at deciphering delicate moments of transient swings.

If reproduced sound is like activities onstage, then the sound of the dual-mono DAC would correspond to a dance scene in Tschaikovsky’s Swan Lake ballet, in which a dozen of so swans dance effortlessly and merrily around the center swan, with every motion and movement definitively displayed. By contrast, the 4x more expensive Audio Note Super DAC would give the onstage presentation a full sweep from the center stage to the farthest corners, vibrant in each character’s activity and, surpassing every DAC‘s I‘ve used, able to communicate changes in dynamic intensity between dancers, as well as that of magnitude and scale from disc to disc.

That said, the 47 Lab DAC’s relative modesty in dynamic scaling and dimensionality was probably more in line with the quality of materials employed. Had Junji investigated application of the one metal with an atomic count of 47 (silver) into the Gemini Progression instead of the copper-laden design, he then would have increased the cost of the DAC a few folds no doubt, the performance of which would then undoubtedly have propelled the silver Gemini as the tour de force in transistor-based implementation.

The current version of the Gemini Progression is a thoroughly tweaked design nonetheless, employing dedicated, outboard cylindrical power supplies for each channel that would have inflated the main chassis’ dimensions many folds to that of the AN Super DAC as well, were the entire process to take place in a single chassis.

Alas, lest Junji rids his rational self and parts with his recognized principle, we may never get to buy another 47 Lab concoction costing anywhere near the MSRP of the PiTrcaer; hence what a small comfort it is, that we still have a DAC that is far ahead of its kind in tonal delicacy and transient agility. For many months, the Gemini Progression served its sibling platter side by side with Kazuo Kiuchi’s $5.5k Harmonix Reimyo K2 DAC, and I am of the opinion that the $7.1k 47 Lab dual-mono DAC, with its most admirable, singular attribute of a coercive, “stress-free” presentation, will find its admirers among many homecoming audiophiles.


The exquisite, timelessly sculpted silvery PiTracer is costlier than many companies’ best CD transport and DAC combined. Yet, once exposed to 47 Lab’s methods of vanishing mechanical stress and delicate signal retrieval process, sealed transport compartment designs would seem almost unnecessarily conservative.

For the past 21 years’ worth of progression in digital audio, playback technology as presented by the PiTracer in its separation of mechanisms for the laser pickup, laser driver and separate spindle motors continues to be an industry first. Considering that the rest of the industry have long been adopting an integrated laser/pickup mechanism with a spindle motor, design of the PiTracer was a powerful and reverberating statement in audio engineering originality.

Sonically, on top of the extraordinarily satisfying and highly differentiating sonics the PiTracer consistently produces, it is also extraordinarily stimulating in the exalted level of sonic refinement it accords to the system downstream.

Recordings of distinguished sonic virtues provided the ultimate testimonials to the PiTracer’s abilities, and lesser recordings were given salvation in the form of an optimal platform. Yet, amidst performance aspects such as dimensionality and dynamic contrasts, the PiTracer’s most extraordinary feat unequalled by other transports was in timbre definition.

Different sonic preferences determines which sonic parameters are to be pursued most earnestly; but even though many of us have given up the seemingly impossible task of tuning our systems to produce the maximum timbre realism in concert with frequency extension and soundstaging and etc, everyone can still easily recognize instances of tonal ambiguity/obscurity in his/her system. Hence, granted that my system is just as colored as the next reader’s in conformity to our own preferences, I found the PiTracer as the first transport able to compel the DACs to produce instrument and vocal timbres of unprecedented contrasts.

In regards to the SACD format, the PiTracer displaced the SCD-777ES when in a partnership with the DAC 5 Special, to the extent that while dynamic potency and tonal richness of the SACD player remained evident, the PiTracer’s rendition of dimensionality, instrument transient definition, sense of scale and tonal shading were all raised to a level eclipsing that of the high resolution format.

Eminently, the PiTracer and DAC 5 Special represented a case for how far a CD system can go. Still, I remain confident on the SACD’s inherent might, as well as the solid value the SCD-777ES continue to represent, despite that the SACD player became inadequate when compared against the likes of PiTracer and DAC 5 Special. Perhaps the most remarkable attribute of the PiTracer yet to many readers was its ability to make hybrid SACD’s CD layer sound superlative. The fact that the PiTracer is the only transport in the world that strictly maintains a 90 degree laser to CD reading angle may have enabled it to extract the most image-perfect data from the pits of a hybrid disc’s CD layer.

This reviewing experience has not only proven to me that the full exploitation of a format’s resolution potentials will always require a high-caliber playback platform, it also reminded me of the pitfall of thinking the importance of acquiring the best digital front end that each of us can buy as secondary.

The PiTracer made me realized that all the DACs, preamplifiers, amplifiers, speakers and the cables were working so hard collectively to deliver the promise of all CD transports that graced my system. With the PiTracer, whatever combination of downstream equipment I put forth, theresult would exceed that achieved by all CD transports that had gone before it.

To those of you who have the required level of financial freedom, and is somehow wondering if you can be using better transport or converter, I hope this review has convinced and motivated you to investigate the possibility of upgrading your digital front end.

As an actual user of Mr. Junji Kimura’s Flatfish CD transport, Progression DAC and Gaincard S dual mono integrated amplifier, I cherish each occasion to the best I can, because each of Mr. Kimura’s creation is definitive in its minimalist approach but is never simple. Insisting that “only the simplest can accommodate the most complex”, Mr. Kimura’s PiTracer represents the pinnacle of his achievement: a machine so elegant in its harmonious shapes and refined in its functionality and purpose, it embodies a modern day sensitivity executed seamlessly in a Japanese traditional master craftsman’s hands.


Sony’s establishment of the SACD standard in 1999 served partially to address the audiophile community’s criticisms towards the Compact Disc format that the company also helped created 15 years earlier, in partnership with Philips of Netherlands. The higher-resolution, SACD format represents an evolutionary inevitability in the progression of digital audio.

Events transpired in the past 3 decades have shown us that format creation has been the most formidable power that Sony continues to demonstrate, to differing results in dazzling arrays of consumer electronics. To music retailers, the emergence of the high resolution format represented the opportunity of re-generating sales of the same music, while the new disc players bring fortunes to hardware establishments.

Putting aside for now arguments in motive and market economy, the creative prowess and resources Sony has at its disposal for wielding is what distinguishes the Japanese electronics giant from the rest of the industry. In the ascension to greatness, nothing can be more valuable to a company than having its products proclaimed as standards in markets worldwide.

Take the company’s initial offering of the SCD-1 and SCD-777ES, for example. The exceptional disc chamber and twin laser-assembly of the pioneering machines as envisioned by Sony are of such originality, that they represent yet another blindingly brilliant triumph of the Japanese giant in an overcrowded industry sector that is over 2 decades old.

47 Laboratory’s 4704 PiTracer CD transport is the only other creation within the industry that dazzles with equal originality.

Associated Equipment:

Digital Front End

Audio Note DAC One 1.1x Signature
Audio Note DAC 5 Special
GW Labs DSP Engine
Harmonix Reimyo DAP-777 20bit K2 DAC
Sony SCD-777ES SACD/CD player


47 Laboratory 4706 dual mono Gaincard S with DACT24 & Cardas posts
Audion Golden Silver Night 300B monoblocks
Decware SE84C
GW Labs 270 tube power amplifier
Harmonix Reimyo CAT-777 preamplifier
Harmonix Reimyo PAT-777 300B stereo amplifier
Linn Klimax Twin
Loth X JI300 integrated amplifier
Reference Line Preeminence Two passive preamplifier
Reference Line Preeminence One Signature power amplifier]
Z-systems RDP-1 Reference Digital Preamplifier


Apogee Duetta Signature
Audio Note AN-E SEC Silver
Celestion SL700
Genesis VI
Loth-X BS1
Rethm 2nd
Tannoy Churchill Wideband
Tannoy TD10


Audio Note Sogon digital cable (1m, RCA)
Audio Note Sogon interconnect (2m pair, RCA)
Audio Note AN-Vx interconnect (1.5m, RCA)
Audio Note AN-V silver interconnect (RCA 1m, 2 pairs)
Audio Note AN-SPx speaker cable (2m, bananas, bi-wired)
Audio Note AN-La copper speaker cable (8 feet, bi-wired)
Canare L-5CFB 75-ohm digital cable (RCA, 1.5m)
Canare D206 110 ohm digital cable (AES/EBU, 1.5m)
Cardas Quadlink 5C (8 feet)
Granite Audio #470 silver cables (RCA 1m, 2 pairs)
Granite Audio #560 AC Mains (2)
Harmonix Reimyo Studio Master AC cord (2)
Illuminations D-60 75 Ohm digital cable (1.5m, RCA)
Loth X
Van den Hul MCD-352 (8 feet)


ISO, Salamander Synergy 20 (2), ASC Tube Traps and Flat Traps

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