Country of Origin
Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (i5, 256GB SSD, 40GB RAM, Sonoma 14), 4TB external SSD with Thunderbolt 3, Audirvana Studio, Qobuz Sublime, Singxer SU-6 USB bridge, LHY Audio SW-8 & SW-6 switch, Laiv Audio Harmony; Active filter: Lifesaver Audio Gradient Box 2; Power amplifiers: Kinki Studio EX-B7 monos & Gold Note monos on subwoofer; Headamp: Enleum AMP-23R; Phones: Raal 1995 Immanis, HifiMan Susvara; Loudspeakers: Qualio IQ [on loan] Cables: Kinki Studio Earth, Furutech; Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps, Furutech DPS-4.1 between wall and conditioners; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 6 x 8m with open door behind listening seat; Room treatment: 2 x PSI Audio AVAA C214 active bass traps
2nd system: Source: FiiO R7 into Soundaware D300Ref SD transport to Cen.Grand DSDAC 1.0 Deluxe; Preamp/filter: Lifesaver Audio Gradient Box 2; Amplifier: Kinki Studio EX-M7; Headamp: Cen.Grand Silver Fox; Loudspeakers: MonAcoustic SuperMon Mini + Dynaudio S18 sub; Power delivery: Furutech GTO 2D NCF, Akiko Audio Corelli; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan]; Sundry accessories: Audioquest Fog Lifters; Furutech NFC Clear Lines; Room: ~3.5 x 8m
Desktop system: Source: HP Z230 work station Win10/64; USB bridge: Singxer SU-2; DAC: Sonnet Pasithea; Headamp: Kinki Studio THR-1; Speaker amp: Crayon CFA-1.2; Speakers: Acelec Model One Headphones: Final D-8000 & Sonorous X, Audeze LCD-XC, Raal-Requisite SR1a on Schiit Jotunheim R
Upstairs headfi system: FiiO R7, COS Engineering D1, Cen.Grand Silver Fox; Headphones: Raal 1995 Magna, Meze 109 Pro, Fiio FT3
2-channel video system: Source: Oppo BDP-105; All-in-One: Gold Note IS-1000 Deluxe; Loudspeakers: Zu Soul VI; Subwoofer: Zu Submission; Power delivery: Furutech eTP-8, Room: ~6x4m
Review component retail: $9'995/ea.
USB-C port for firmware updates.
Michal Jurewicz: "As you may remember, we were showing prototypes of our Empire GaNFet amps for the last few years while still working on tuning and commercializing the circuit. I also followed and found very interesting your reviews and comments on GaNFet including podcast and YouTube discussions with John Darko. During this R&D period I consulted and collaborated with Skip Taylor of Elegant Audio Solutions and Alberto Guerra who had a head start with the technology and early accomplishments on the GaNFet amplifier front. GaNFet Class D tech can be essentially described as pulse-density modulated class D with class A sound potential. It solves the problem of class D's grungy top end that's impossible to fix by other means such as Bruno Putzeys' Purifi approach of heavy negative feedback. In my opinion the silky smooth tube-like treble combined with transistor-typical tight bass and several other advantages such as speed and efficiency will make GaNFet class D the dominant hifi amplifier technology in the next 10 years."
"Because the relationship between the circuit's behavior and its harmonics is nonlinear unlike in classic A/B transistor curves but instead a modulation like an FM station, our R&D took a while to figure out the dependencies between circuit artefacts and subjective sound quality. Generally I can now say that while all GaNFet designs tend to sound good and better than classic MosFet class D, they can also sound very different from one another. For example, Alberto's Gran Vivace monos which you reviewed have a warmer top than other such amps but replacing a switching power supply with a large toroidal still has a major impact etc. In other words, there is a lot of room to tune GaNFet amps this way or that. For our Mytek business strategy, we now finalized a bridgeable stereo GaNFet power module that will be at the heart of all our amplifier products going forward, with the Stereo Monoblock the first model and others to follow next year."
"In practical ways we have now tested the last iteration of the amp that became the current production model since we showed it in Munich. We tuned the top to be slightly warm without smearing to retain the precise transients and clarity. This design is getting extremely positive reactions from listeners and dealers who had opportunity to hear it. For example at Munich 2024, people commented how our room with Empire electronics had the fairly precise and accurate Børresen X3 speakers "sing" while being edgy and hard in Børresen's own downstairs rooms where Aavik amps based on Pascal class D were responsible for the hard treble. In at least ten causal shootouts at dealerships, our Empire monos were favored over classics such as class AB Pass Labs, McIntosh, D'Agostino, Chord and CH Precision precisely because of our non-fatiguing beautiful top end and pretty much perfect rest. To sum up, I think we have an extremely good-sounding amp, a harbinger of what GaNFet technology can bring. Our sound has a lot of similarities to what you know from Alberto's AGD designs but still its own wrinkle. The amps are made in Warsaw so door-to-door shipping to Ireland should be easy."
In the AGD range, the equivalent model is the Solo [$23.5K/pr] which delivers 500W/4Ω and also implements a linear power supply.
Claimed to be 20 x faster than their silicon brethren to reduce the transitional 'dead time' between on/off states, Mytek's gallium-nitride outputs co-developed with Grzegorz Jankowicz switch 50 amperes at 768kHz so in the outermost bat sphere. "This allows for a faster clock, higher bandwidth, efficiency that jumps from 85% to 95% to eliminate the need for heatsinks and less EMI. Our faux tube is a purely decorative element and homage to AGD's original GaNTube¹". An 800-watt linear power supply supports 200/400wpc into 8/4Ω stereo, 400/700W in bridged mono. Selectable voltage gain is 23dB or 29dB, max swing ±65V. Input impedance is 10kΩ, output impedance below 20mΩ. Bandwidth is 2Hz-70kHz. The guts fit inside a milled-from-solid aluminium case of 21.6 x 35.5 x9cm WxDxH that weighs 14kg.
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¹ By ensconcing his modulator and power stage inside a multi-pin glass bulb, Alberto Guerra's entire output stage pulls out like a classic vacuum tube. This makes upgrades to more powerful or superior-spec versions released as the tech progresses child's play, no screw driver involved. As we saw, Michal's module connects vis two multi-pin headers to remove just as easily once the six bolts of the bottom lid are undone.
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