Walk into a room at a hi-fi show touting low-powered…
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In this hobby, nothing's for nothing. To get that gorgeous midrange, with its harmonic depth and inner detail, tube-amp enthusiasts are willing to give up some things in the bass. Tube folks put up with heat and occasional maintenance—routine or otherwise. To get the ideal middle, fans of single-ended triodes are even willing to shave off considerable dynamic range and settle for ultra-efficient speakers that often have limited response at the frequency extremes. Those who say nothing is lost by preferring tubes are in denial.
There was nothing soft or romantic about the Baldur 70's overall sonic presentation. While in terms of control, solidity, speed, and extension the bass naturally suffered compared to my solid-state reference, it was sufficiently well-defined, controlled, and extended to avoid mushiness—more so than I've heard from many tube amps. When I played rock reference recordings, such as an original UK pressing of The Clash's London Calling (CBS Clash3), the Baldur upheld its end of the bargain, reproducing both the prominent kick drum and bass on "Jimmy Jazz," for example, with enough rhythmic…
Sidebar 1: Specifications
Description: Push-pull, class-A, triode monoblock power amplifier. Tube complement: two 2AU7, 12AX7, two 6N6P; four 6AS7G. Maximum power output: 70W into 8 ohm load at 1% distortion (18.5dBW). THD at rated output: 0.3% (50W, 100Hz–10kHz). Power bandwidth: 10Hz–50kHz ±3dB. Damping factor: 20. Input sensitivity: 0dBm (775mV).
Dimensions: 12.8" (325mm) W by 11.8" (300mm) H by 15" (385mm) D. Weight: 35.25 lbs (16kg).
Serial Numbers Of Units Reviewed: 170205, 180205.
Price: $7200/pair. Approximate number of dealers: 5. Warranty: 3 years parts & labor on…
Sidebar 2: Associated Equipment
Analog Sources: Continuum Audio Labs Caliburn, Simon Yorke S7 turntables; Continuum Audio Labs Cobra, DaVinci AudioLabs Grandezza Reference, Graham Engineering Phantom, Immedia RPM-2 tonearms; Dynavector DRT XV-1S, Graham Engineering Nightingale, Lyra Titan (stereo, mono) cartridges.
Digital Sources: Musical Fidelity kW SACD player, Alesis MasterLink hard-disk recorder.
Preamplification: Manley Steelhead phono preamplifier; Musical Fidelity kW Hybrid preamp.
Power Amplifiers: Musical Fidelity kW monoblock & kW750, Music Reference RM-200.
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Sidebar 3: Measurements
As is my usual practice, I preconditioned the Baldur 70 by running the amp at 1/3 power into 8 ohms for an hour before performing any measurements. Via the Baldur's unbalanced (RCA) input jack, its voltage gain at 1kHz into 8 ohms was a high 31.55dB from the 8 ohm output transformer tap, 28.45dB from the 4 ohm tap. Unusually, the gain via the balanced (XLR) jack was 6dB lower from both taps. As the amplifier was noninverting via both inputs, the difference in gain suggests that the balanced input isn't truly balanced, but simply has pin 3 of the jack tied to…
Last September, in Vol.15 No.9, I started my quest for the Ultimate Kilobuck Tube Amp with reviews of the $995 Panor/Dynaco ST70-II and the $1695 Nobis Cantabile. While neither really fit the bill—the Dynaco fell a bit short in terms of sonics, while the Nobis was priced a bit higher than a thou—they got me thinking of the Ultimate Kilobuck Tube Preamp. Because the greatest amp in the world can only sound as good as whatever drives it, and there's no sense looking for a kick-ass affordable tube amp if you're going to play Scrooge McDuck when it comes to the preamplifier.
Now, the…
Popping the hood showed the li'l C-J to have decent, but hardly topnotch build quality. The bare-metal wire links from the RCAs to the printed circuit board look like something out of an old Dyna, while most of the audio signal path is carried on long pcb traces that run the length of the preamp and back. Still, for a thousand clams, the parts quality C-J's managed to achieve with their baby preamp is pretty impressive. The volume control is a high-grade blue ALPS unit, and low-noise Corning metal-film resistors and polystyrene and polypropylene film caps populate the audio stages.
The…
What the PV10A does wrong
The PV10A's most striking weakness is its lack of detail in comparison with a top-ranked preamp like the Melos SHA-1. While the budget C-J is no slouch in this area, I heard a distinct reduction in the amount of recorded detail when switching between the PV10A and the Melos. Things like the air riding on top of brushed cymbals, space between and behind instruments and voices, and subtleties in complex mixes were consistently less clear with the C-J than with the Melos. On rich sonic tapestries like Los Lobos' Kiko and Jimi Hendrix's "1983: A Merman I Should…
The PV10A's most striking weakness is its lack of detail in comparison with a top-ranked preamp like the Melos SHA-1. While the budget C-J is no slouch in this area, I heard a distinct reduction in the amount of recorded detail when switching between the PV10A and the Melos. Things like the air riding on top of brushed cymbals, space between and behind instruments and voices, and subtleties in complex mixes were consistently less clear with the C-J than with the Melos. On rich sonic tapestries like Los Lobos' Kiko and Jimi Hendrix's "1983: A Merman I Should…
The C-J seemed to integrate the sounds of the electric and acoustic guitars into more of a swinging rhythm, which reinforced my feelings throughout the comparison that the PV10A had a much better sense of pace and rhythm than the Adcom. While tonally the more neutral of the two preamps, the Adcom wasn't as effective at communicating music with a strong sense of rhythm and drive.
The one area in which the Adcom's phono stage beats the PV10A's is noise. The GFP-565 has one of the most scarily noise-free MM phono stages I've ever heard, while the C-J has a bit more noise than I'm accustomed…
Sidebar 1: Corey's System
The PV10A did time in two rooms: my He-Man rig and my Real World system. The He-Man rig consisted of either the VTL Deluxe 225 tube amps or the cool-man Aragon 4004-II solid-state muscle amp driving ProAc Response Two speakers augmented by the mighty Muse Model 18 subwoofer. Analog source was Sumiko's butt-nekkid Blue Point Special cartridge mounted on Roksan's Radius turntable and Tabriz arm (review to come). Digital delight was derived from a duo of Thetas: the DS Pro Basic II processor and Data II transport. Interconnects were Kimber KCAG and AudioQuest Lapis…