Since the 70s, solid-state amplification designs have been relying on field-effect transistors to deliver power, and the emergence of the metal-oxide semiconductor field-effect transistors (MOSFET) in the early 80s ushered in the era of high-current power amplification. Recent advancements in photolithography process are revolutionizing the density of the MOSFET, condensing it from half a million parts per square inch in the 1980s to 12 million today, resulting in the creation of the most powerful MOSFETs in history.
GamuT Audio is the first high-end audio company to incorporate this latest MOSFET technology in solid-state amplification, and their D200 Mk III is one such uniquely equipped stereo power amplifier. GamuT is of the belief that conventional MOSFETs falter in the need to work in numbers in parallel configurations just to overcome their individual limitation in power handling, a practice that would suffocate musical intricacies from aggregated, minute variance manifested by each MOSFET.
GamuT claims that the D200 Mk III’s single MOSFET topology will instead preserve the music’s finer dimensionality details better than other MOSFET amplifiers. In the D200 Mk III, two such single MOSFETs are assigned to handle each channel’s positive and negative supply, producing 200 watts at 8Ω and 400 watts at 4Ω. Although this new, powerful MOSFET-based amplifier is designed to aerospace industry specifications and capable of generating 500 watts of output with current delivery at 100 Ampere continuous and 300 Ampere at peak, GamuT set the output threshold of the D200 Mk III at 47 Amp, with the lowest impedance tolerance of 1.5Ω, and redesigned circuit layout to compliment the single MOSFET.
For GamuT customers using speakers of unusually difficult loads, GamuT recommends a special version of the D100 which is only made on request.
Techniques exercised in creating the D200 Mk3’s protection circuit is extraordinarily thoughtful, and GamuT names it “Intelligent Protection”. Detecting DC errors, subsonic signal surges from severely warped records, sustained ultrasonic signals sent to the tweeters, thermal instability, low impedance loads and short circuits, the D200’s protection circuit takes advantage of the new single MOSFET’s high tolerance and will mute for only a second when a one millisecond test pulse is generated.
With this sophisticated circuit protection implementation, GamuT claims that only one fuse is required for realization of “pure, non-distorted audio, giving music its full, exciting dynamic range”.
The D200 Mk III is equipped with pairs of “Direct” and “Normal” speaker terminals, in which the “Direct” output will bypass the coil and resistor, designed for protection against capacitive speaker and cable loads. GamuT claims a better preservation of fidelity in the treble range via the “Direct” outputs.
GamuT also claims to have incorporated a consistent, modular design in their amplifiers which allows the owner of their 1990 amplifier to upgrade to the latest design, or even a model upgrade from D100 to D200.
Last not least, housed in an all-aluminum chassis with a front panel sanded to “a silky smooth surface”, the D200 Mk III features a dual-mono configuration with two mains transformers, rectifiers and two pairs of large power capacitors. On this third, current revision of the D200, designer Michael Edinger has the following to offer:
The Mk.III design uses 95% of the same components, while some caps were changed to better types. The D200’s printed circuit board was, at first, designed as single-sided copper, then later upgraded to through-plated, double sided, and at the third upgrade, the PCB copper tracks were ripped up and replaced with the same, but this time, new electrical connections, and reoriented and moved to the most appropriate section to take advantage of signal synergy in “friendly” adjacent tracks, and improved isolation from tracks carrying heavy, pulsating currents. The outcome was a purer-sounding amp with less IMD, enhancing sound stage and detail rendition and reduces listening fatigue.
On the subject of preamplification design, GamuT maintains that the “simple is better” maxim is not necessarily universally applicable, and further asserts that “less is less… and the correct number of parts is the right number of parts, no more, no less.” GamuT also proclaims that the low-noise power supply technology put into both of the company’s D3 and the C2R preamplifiers achieves a 2nd and 3rd harmonics distortion of 0.0002%, translating into a dynamic range of 114dB: “If purity has a sound, this is it.”
A top design priority GamuT places on the D3 is the preamplifier’s capability of vanquishing interconnects impedance. The D3’s input and output impedance are set to the unusual levels of 1kΩ and 75Ω respectively, a measure GamuT claims will allow music to flow “unimpeded through the internal maze of connections and emerges intact and pristine”, as well as being able to control interconnects effectively. GamuT claims that the D3’s output impedance produces a sound quality even surpassing the company’s previous best efforts in passive preamplification.
There are four pairs of RCA inputs and one pair of balanced XLR inputs, and two pairs of XLR outputs are provided for bi-amping, in addition to one pair of RCA outputs and one pair of Record Outputs on RCA as well. Among all the inputs and outputs, both the Record and RCA Output have separate buffer amplifiers to avoid impeding upon the XLR outputs’ Common Mode Rejection Ratio.
While the front panel displays input selections of MM/MC, Tuner, Tape, HTH, CD and BYPASS, the CD inputs are the only ones in XLRs, and the HTH Home Theater Input actually forwards incoming signal at full-volume to the outputs. Also, the MM/MC RCA inputs are not provisioned with a phono stage and in fact require the addition of pre-preamplification to provide the support its name suggests. For this review, I sent my DAC’s output to this MM/MC input.
Volume control is carried out via an ALPS potentiometer, and driven by a motor if accessed via the optional remote. NEC’s telecommunication-grade EA2 relays handle input selection.
System Setup & Audition
Moving the D200 Mk III around was surprisingly easy, given its considerable weight, as its side fins were rounded and made for quite painless handlings. At one time, I put it on top of one of my Salamander Synergy 20 racks as the normal center spot was taken by heavier amplifiers in turn, and for its power capability, the GamuT was the most powerful amplifier to date that was also light enough for top shelf consideration.
In addition to GamuT’s own $5,999 D3, Audio Note’s $10k M5 phono and the passive Reference Line Preeminence Two also took turns in partnering with the D200 Mk III, although both D3 and M5 evoked considerably better dynamic contrasts from the power amplifier than the passive Reference Line. Understandably, the Reference Line preamplifier was created to drive its own high-input level Preeminence One Signature power amplifier, and thus was eventually left alone for the purpose of this review.
Digital front end support was by the $27k 47 Laboratory PiTracer CD transport and the $32k Audio Note DAC 5 Special. Audio Note’s AN-Vx silver interconnects linked the D200 Mk III to the D3, and AN’s Sogon silver cables provided connection between the DAC 5 Special to D3, as well as PiTracer to the DAC. Loudspeakers rotated for audition with the GamuT amplification included Apogee’s Duetta Signature, Audio Note’s $40k AN-E SEC Signature, the $30k AN-E SEC Silver, Celestion’s SL700, Ensemble’s $10k Figura, the Genesis VI, as well as Tannoy’s $20k Churchill Wideband and $8k TD10.
The GamuT system drew power directly from the dedicated wall outlets via two Harmonix Reimyo Studio Master WattaGate power cables.
In controlling the D200 Mk III, the Audio Note M5 and GamuT D3 preamplifiers represented respective virtues from the vacuum tube and solid-state schools, and both had induced irresistible sonic flavors from the D200 Mk III.
In a display of agility and power, the D3/GamuT D200 Mk III amplification drove the 86dB/4Ω Apogee Duetta Signature into states of extremity. In reproducing the rumbling “do-taiko” in Ondekoza (JVC XRCD2 SVCD-1027), the drumming’s variance in force and speed sounded it’s most descriptive and lucid ever from the GamuT-driven Apogee.
The spectral presentation released by the partnership was the most revelatory in memory, as the frail intonation of the Japanese flute and the abyssal riding of the gargantuan drum cast astounding waves of contrasts and divides between the two instruments.
In addition to the portrayal of the flute’s feebleness, the GamuT amplification disclosed a serenity most revealing in the texturing and transients of the instrument. And though powerful, the GamuTs were ever so alluring in the periodic and purposeful highlighting of ambience cues.
Ensemble’s 87dB/6Ω, $10k Figura loudspeaker, which I reviewed in April 2005, had been a similarly demanding transducer capable of laying siege to all but the more powerful of amplifications. In the company of the GamuT amplification, the Figura exhibited a rare spectral balance utterly devoid of indulgence, insomuch that the tones and bodies of classical oboes and trombones were superbly-defined in their spotless voicing and immaculate dimensionality.
Alternating preamplification with Audio Note’s $10 M5 phono, the Ensemble speaker manifested a richer midrange and a more dimensional soundstaging, at the expense of a probing sonic prowess that only solid-state designs can take credit for.
Perhaps the most surprising partnership was the one between the GamuT system and the $40k AN-E SEC Signature, in which the D3 and D200 Mk III evoked wholesome refinements from the Audio Note speaker, as the 95dB/8Ω, high efficiency speaker made use of the solid-state amplification’s spectral refinement to attain considerable vigor and vitality, lending acoustic instruments a remarkable tonal definition and refinement previously lacking in other solid-state amplifications.
For example, in playing the JVC XRCD Songs of A-Tao (JVC SR-XRCD-001), the GamuT-driven Audio Note speaker summoned extraordinarily dynamic and vibrant sonority from the acoustic guitar, coercing a supreme palette that was principally infallible in the unusually aural and opulent instrumental reenactment, a unique experience I was compelled to re-visit time and again.
Expertly designed and exemplarily executed, the GamuT amplification channeled an unprecedented broadness of tonal impartiality through speakers being driven, making the strongest case for an inherently flat spectral balance in amplification design.
Despite GamuT’s inquisitive insistence in equipping its designs with a complimenting number of parts, the company’s D3 preamplifier and D200 Mk III power amplifier manifested themselves as illustrious personification of the best in solid-state arena, possessing a spectrally linear core disposition, a powerful trait that does honor to the company’s professional credentials.
The star of the GamuT system is the $6,500, D200 Mk III single MOSFET amplifier, its ability to exert control over cones and ribbons alike was in the league of the $9k Linn Klimax Twin, thus admirably of reference caliber. Its interaction with the $10k Audio Note M5 tube preamplifier further illustrated an utterly impartial sonic disposition that would highlight individual components up- and down-stream of it, and exposed individual speakers’ influence on program materials.
When accompanied by the matching D3 preamplifier, the D200 Mk III unveiled a unique, exacting competency worthy of its place in the most demanding of systems. Likewise, professionals will liken their unrelenting need for sonic objectivity to what the GamuT D3/D200 Mk III amplification can contribute, and uncompromising audiophiles will likely hail the GamuT as the gem of the game.
At closing, I reckon that any distinctions in the respective sonic presentation by the D3 and M5 to be so equally superfluous as to render any comparison attempts easily a conceited concession of personal preferences.
For Dagogo readers contemplating purchase of a $10k+ solid-state amplifier, I urge them to audition the D200 Mk III with the D3, for an experience not likely to be repeatable elsewhere.
Digital Front End
47 Laboratory 4704 PiTracer CD transport
Accustic Arts Drive I
Accustic Arts DAC I Mk 3
Audio Note DAC One 1.1x Signature
Audio Note DAC 5 Special
47 Laboratory 4706 dual mono Gaincard S with DACT24 & Cardas posts
Audia Flight PRE
Audia Flight 100
Audio Note M5 preamplifier
Decware SE84C power amplifier
Harmonix Reimyo PAT-777 300B stereo amplifier
Linn Klimax Twin stereo power amplifier
Loth X JI300 integrated amplifier
Monarchy Audio SM-70Pro monoblocks
Reference Line Preeminence Two passive preamplifier
Reference Line Preeminence One Signature power amplifier
47 Laboraotory 4722 Lens minimonitors
47 Laboratory Essence
Apogee Duetta Signature
Audio Note AN-E SEC Signature
Audio Note AN-E SEC Silver
Tannoy Churchill Wideband
Tannoy Dimension TD10
Tannoy ST-200 SuperTweeter
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 Sogon LX speaker cable (5 feet, spade/banana, bi-wired)
Audio Note AN-SPx speaker cable (2m, bananas, bi-wired)
Audio Note AN-La copper speaker cable (8 feet, bi-wired)
Boelen Digital-Precise digital cable (1.5m, RCA)
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 HS101-SLC speaker cable (1.5m, spade/banana, bi-wired)
Harmonix X-DC Studio Master Wattagate 330+350 power cable (2) (1.5m)
Illuminations D-60 75 Ohm digital cable (1.5m, RCA)
Van den Hul MCD-352 (8 feet)
Salamander Synergy 20 (2), Twin 30 and Amp Stand
- (Page 1 of 1)