Digital sources: Mark Levinson No.31.5 CD transport; Mark Levinson No.30.6, Benchmark DAC 1, Musical Fidelity X-DACV3 D/A processors; Technics DVD-A10 DVD-Audio player; Ayre C-5xe, Linn Unidisk SC universal players.
Preamplification: Mark Levinson No.380S, No.326S preamps.
Power amplifiers: Mark Levinson No.33H monoblocks.
Loudspeakers: MartinLogan Montage.
Cables: Interconnect: AudioQuest Cheetah, Madrigal CZ Gel-1 balanced. Speaker: AudioQuest Kilimanjaro. Digital: Kimber Illuminations Orchid, DH Labs AES/EBU, AudioQuest SVD-4, Stereovox hdxv…
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Sidebar 2: Associated Equipment
Sidebar 3: Measurements
My estimate of the Reference Signature S2's voltage sensitivity agreed with the specification at 88.2dB(B)/2.83V/m, which is 1dB higher than the average of the speakers I have measured. Its impedance (fig.1) dips briefly below 4 ohms in the lower midrange, reaching a minimum of 3.6 ohms at 180Hz, but stays above 8 ohms for much of the audioband. Even with a combination of 5.2 ohms impedance and –40º capacitive phase angle in the upper bass at 112Hz, the Paradigm will not be too demanding a load for its partnering amplifier to drive. A slight wrinkle at 200Hz in…
Conrad-Johnson is one of audio's "marquee" companies, and charges accordingly. The Premier Twelve tube monoblock power amplifier, rated at 140W, sells for a rather steep $3495 each, meaning that unless you listen in mono, be prepared to lay out almost $7000 just for the amplification link in your audio chain. Apparently, many audiophiles feel the money is well spent: according to Conrad-Johnson, the Twelve has been a consistently strong seller during its approximately five-year production history.
What do you get for your $7000, aside from 140Wpc and a top-shelf name? Physically, you get…
The Twelves always sounded confident and in control—tonally, spatially, and temporally—particularly at the frequency extremes. On the bottom, both acoustic and electric bass sounded tight yet supple, and totally "in character" tonally. On top, the Twelve's transient performance was faultless, portraying cymbal crashes with the crisp, splashy shimmer you hear live. On good recordings, strings bristled with energy, yet never sounded hard or unnaturally edgy.
Along with exemplary top-to-bottom "attack," the Premier Twelve portrayed decay with equal propriety, resolving low-level information…
Yet when I switched from the C-Js to the VTLs and replayed Neil Young's "I Am a Child," the VTLs disappointed—they slowed the pace, took some snap off the snare and kick drum, and reduced the delineation between the images and the ambience behind. Moving to Gershwin's Concerto in F, though, the VTLs better suggested the hall, and offered a slightly more diffuse presentation that some may find more akin to being there live. As one manufacturer said to me about an update of an unrelated product, "You know what? I like the original version better. I go to a lot of live concerts, and live, you…
Sidebar 1: Specifications
Description: Vacuum-tube monoblock amplifier. Tube complement: one 5731, two 6FQ7, four 6550. Maximum power: 140W into 4 ohms (18.5dBW), 30Hz-15kHz, at no more than 1% THD or IMD. Frequency response at 10W: 20Hz-20kHz, ±1dB. Hum and noise: 98dB below rated power. Sensitivity: 900mV to rated power. Input impedance: 100k ohms.
Dimensions: 17.5" W by 7.25" H by 15.25" D. Weight: 51 lbs.
Serial numbers of units reviewed: 6101307, 6101308.
Price: $6990/pair. Approximate number of dealers: 70.
Manufacturer: Conrad-Johnson Design, Inc., 2733 Merrilee Drive…
Sidebar 2: Associated Equipment
Analog sources: Simon Yorke turntable; Simon Yorke, Graham 2.0, Immedia RPM2 tonearms; Lyra Parnassus D.C.t, Transfiguration Temper, Koetsu Urushi, Crown Jewel Special cartridges.
Preamplification: Ayre K-1 preamplifier; Audio Research PH3SE, Pass Aleph Ono phono sections.
Power amplifiers: VTL MB 450 tube monoblocks.
Loudspeakers: Audio Physic Virgo, Sonus Faber Concerto Grand Piano; Audio Physic Rhea subwoofer.
Cables: Yamamura Millennium 6000, Cardas Golden Cross, Cardas Neutral Reference, Electra-Glide interconnects; Yamamura speaker…
Sidebar 3: Measurements
Following its preconditioning test, the Conrad-Johnson Premier Twelve was hot—typical for a tube amplifier. The bias was found to be slightly off during the distortion measurements, was recalibrated, and the prior measurements were rechecked to ensure that the results had not changed significantly. (Except for the distortion, they had not.)
The amplifier's voltage gain into 8 ohms measured 28.5dB. The input impedance measured 98k ohms. The DC offset was a very low 1.1mV. The Premier Twelve is noninverting—a positive-going input emerges positive at the…
One of my favorite parts of attending Stereophile's Home Entertainment shows—aside from seeking out the sexy new gear and pressing the flesh of readers—is the "Ask the Editors" panel discussions. What begins as a Q&A session usually turns into a free-for-all, as the outspoken and opinionated likes of Sam Tellig, Michael Fremer, Ken Kessler, and John Marks barely give room for wallflowers such as Art Dudley and yours truly to express our opinions—except when editor John Atkinson asks each of us, in turn, to cast our votes for the "most interesting rooms to visit." At both the HE2004 and…
Sidebar 1: Specifications
Description: Two-way, reflex-loaded dynamic speaker with integral stand. Drive-unit: 4" cone unit with a neodymium magnet run full-range, 6.5" honeycomb-cone woofer with neodymium magnet. Frequency range: 45Hz–20kHz. Sensitivity: 90dB/2.83V/m. Nominal impedance: 6 ohms. Maximum power handling: 60W.
Dimensions: 15.6" (400mm) H by 7.8" (200mm) W by 13.25" (340mm) D. Weight: 19.8 lbs (9kg). Stand: 22.6" (580mm) H by 10.9" (280mm) W by 15.6" (400mm) D. Weight: 15.4 lbs (7kg).
Finishes: Black, matte or gloss.
Serial numbers of units reviewed: P220002/3.
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