Description: Solid-state two-channel amplifier. Maximum output power: 400Wpc continuous into 4 ohms (23dBW). Input impedance: 10k ohms, unbalanced, 20k ohms balanced. Output impedance: 0.08 ohm at 7kHz. Frequency response: 5Hz–45kHz, –3dB. THD: <0.007% at 1kHz up to 400Wpc, <0.03% at 7kHz up to 400Wpc.
Dimensions: 17" (435mm) W by 7" (180mm) H by 16" (410mm) D. Weight: 46.5 lbs (21.1kg).
Serial Number of Unit Reviewed: A0000483.
Price: $4990. Approximate number of dealers: 50.
Manufacturer: Halcro, Wayville SA 5034, Australia. US distributor…
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Sidebar 1: Specifications
Sidebar 2: Associated Equipment
Analog Sources: Linn LP12 turntable, Naim Armageddon power supply, Naim Aro tonearm; Miyabi 47, Linn Akiva, Incognito Shibui cartridges; Tamura TKS-83 moving-coil step-up transformer.
Digital Sources: Naim CD5x, Ayre CX-7e CD players; EMM Labs CDSD2/DCC2 SACD player.
Preamplification: Audio Note M3; Linn Linto phono preamplifier.
Power Amplifiers: Lamm ML2.1 monoblocks.
Loudspeakers: Quad ESL-989, Audio Note AN-E Lexus.
Cables: Interconnect: Audio Note AN-Vx, Nordost Valhalla. Speaker: Audio Note AN-SPe, Nordost Valhalla. AC: JPS Labs The…
Sidebar 3: Measurements
As with all amplifiers that use a switching output stage, examining the Halcro Logic MC20's performance on the test bench was complicated by the presence of RF energy in its output. Unless this energy is filtered, you can never be sure that you're not actually measuring the interaction between the RF content and the test gear instead of the absolute performance of the amplifier under test. (For a discussion of this subject, see my "Measurements" sidebar accompanying Robert Deutsch's review of the PS Audio GCC-100 amplifier in January.)
Fig.1, for example,…
Jim Austin wrote about the Halcro Logic MC20 in June 2009 (Vol.32 No.6):
The $4995 Halcro Logic MC20 is a lesson in stereotypes defied. It demonstrated that pretty much everything I ever assumed I knew about digital amplification is wrong.
My tastes as an audiophile lean toward the simple. The more direct and simple the connection between the original musical source and my eardrums, the happier I tend to be. I love the simplicity and elegance of analog transducers and step-up transformers converting mechanical vibrations into moving electrons in a way that I find direct and easy…
Sidebar: Jim Austin's Associated Equipment
Analog Source: Rega P7 turntable & RB-700 tonearm, Zu Audio DL-103 phono cartridge.
Digital Sources: Marantz SA-7S1 SACD/CD player, Benchmark DAC1 D/A converter.
Preamplification: EAR 834P phono preamplifier, Balanced Audio Technology VK-52SE line-level preamplifier.
Power Amplifier: Balanced Audio Technology VK-55SE.
Cables: Digital: Stereovox HDXV. Interconnect: Q-Audio Tao (unbalanced), Mogami (balanced). Speaker: Chord Odyssey. AC: Belden, PS Audio Statement.
Accessories: Generic steel equipment rack with wooden shelves,…
"My original goal was simply to design a better turntable than the Linn because at that time in the UK, Ivor Tiefenbrun was the man—he was the patron saint and all that. And all the hi-fi mags were full of Linns. He did for turntables, in a way, what Mark Levinson (the man) did for amplifiers."
So said turntable designer Simon Yorke when I visited him recently in Washington, DC. Yorke's motivation 15 years ago wasn't competitiveness, he recollected; it was that, at the time, he couldn't afford a Linn Sondek.
What was this 40-year-old Brit doing in the nation's capital?…
The motor drives a "transfer bearing" (set in another freestanding enclosure) topped with four concentric pulleys: one for drive, plus 331/3, 45, and 78rpm operation. Depending on which speed you've chosen, the main O-shaped drive belt fits into one of three wide grooves cut into the side of the platter. Why three grooves? If the belt doesn't ride precisely centered in the groove, it will chafe against the groove wall as it exits and enters, increasing wow and flutter.
With its low-torque motor, flexible belt, and heavy platter, the Yorke 'table relies on a degree of initial "slip" for…
Armed conflict
Was I hearing the arm or the 'table? The only way to find out was to mount the Graham and Immedia arms on the Yorke 'table and listen some more. I ended up with the Yorke/Immedia/Graham on the Zoethecus constrained-layer-damped equipment stand, and the TNT on the Vibraplane (it barely fit, and I couldn't use the flywheel), and then on the Symposium board on the Vibraplane (everything fit with ease, including flywheel). I also varied the amount of air in the four TNT towers from none to overinflated, just to see what effect it would have on the sound. And I removed the…
Was I hearing the arm or the 'table? The only way to find out was to mount the Graham and Immedia arms on the Yorke 'table and listen some more. I ended up with the Yorke/Immedia/Graham on the Zoethecus constrained-layer-damped equipment stand, and the TNT on the Vibraplane (it barely fit, and I couldn't use the flywheel), and then on the Symposium board on the Vibraplane (everything fit with ease, including flywheel). I also varied the amount of air in the four TNT towers from none to overinflated, just to see what effect it would have on the sound. And I removed the…
Sidebar 1: Specifications
Description: Belt-drive, suspensionless turntable and tonearm with outboard AC synchronous motor and "transfer bearing." Speeds: 331/3, 45, and 78rpm. Tonearm: undamped, medium-mass unipivot design with adjustable VTA. Effective length: 233.2mm. Overhang: 17.8mm. Offset angle: 23.64°.
Dimensions: Weight: 40 lbs.
Serial number of unit reviewed: 035.
Prices: Turntable plus arm, recommended list price, $10,000; importer direct price, $8500. Packaged with active Vibraplane ($5000), $11,500. Approximate number of dealers: currently direct sales nly. Warranty…
Sidebar 2: Associated Equipment
B>Phono Cartridges: Transfiguration Temper, Lyra Clavis DC, Parnassus DC, AudioQuest Fe-5, Grado Reference, Goldring Excel XV, van den Hul MC 10 Special.
Tonearms: Graham 2.0, Immedia RPM.
Preamplification: Ayre Acoustics K-3 preamplifier with phono stage, Audio Research PH3SE and Pass Ono phono sections.
Power Amplifiers: Conrad-Johnson Premier Twelve, VTL MB 450.
Loudspeakers: Sonus Faber Concerto Grand Piano, Audio Physic Virgo, Audio Physic Rhea subwoofer.
Cables: Yamamura Millennium 6000, Cardas Golden Cross interconnects and…