Audio Research MP1 multichannel preamplifier
Y'see? There's still a need for analog multichannel, and the…
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Me, I'm still a music guy. As my wife said, after watching and appreciating the drop-dead-gorgeous quality of HD video, "It's nice, but I don't see the big deal." I guess she's a music gal. On the horizon—perhaps to be unveiled this month, at the 2007 CEDIA Expo—is a new generation of players and processors that will take full advantage of the audio capabilities of these media. I hope that that will encourage the recording industry to release music titles of equal quality.
Sidebar: Recordings In The Round
BERLIOZ: Requiem Toby Spence, tenor; Roger Norrington, Stuttgart Radio Symphony Orchestra, Stuttgart Southwest German Radio Vocal Ensemble Hänssler Classic SACD 93.131 (2 SACDs)
What an exciting surprise! Roger Norrington's earlier Berlioz struck me as lightweight, but this is a phenomenal Requiem that I find musically and sonically superior to the multichannel competition from Robert Spano (Telarc) and Maurice Abravanel (Silverline, Vanguard). While the big moments are thrilling, with the most intense Tuba Mirum I have experienced from a…
A moment of silence, please, for the mouse in my shed: I've had a trap there for weeks, baited with peanut butter—I should have just waited for the food poisoning to do its work—and the poor little bastard finally found it.
It was a bad end, but not as bad as starvation, or being swallowed by a snake, or torn apart by a house cat. He might also have died from a severe blow to the head, had the glass jar I threw at him three Saturdays ago found its target instead of the wall behind him. (That dumb stunt was made even more exquisitely stupid by the fact that the jar still had a little…
We've also spoken of transformer impedances—numbers that describe their primary and secondary coils—but those, too, can't be understood in isolation of the gear with which these coils will be used, or even each other. It's possible to describe the DC resistance of a coil simply by measuring it, but it isn't possible to describe the AC impedance of a coil without observing it at work, in a complete circuit with an exemplary source or load. Consequently, the impedance specifications published by transformer manufacturers should be thought of abstractly: For the most part, primary impedance…
Tweaks come and go. When a new one creates a buzz in audiophile circles, I generally prefer to wait and see if it's still around after the initial excitement has subsided. I'd heard about "audiophile" fuses some time ago, and although the likelihood of them making a significant difference didn't seem as farfetched as such tweaks as the "intelligent chip" or the "clever little clock," I didn't feel inclined to try them. I was persuaded otherwise by the confluence of two separate influences: a report by Michael Fremer, in the February 2007 Stereophile, that the HiFi-Tuning fuses produced a "…
"Tomorrow we'll go over to Larry Archibald's house and pick up the Threshold amplifiers."
It seemed like an intimidating project to me, but Danny Sandoval, Stereophile's intrepid chief of Shipping and Receiving, didn't bat an eye. But then, anyone who'd schlepped the Thiel CS-5s out to the desert in the predawn hours—to be photographed for Stereophile's June 1990 cover—wasn't likely to be defeated by a pair of measly 130-pound amplifiers.
As for me, well, I've been known to go into training at the prospect of moving loudspeakers half that weight. Still, the anticipation of…
Design
There's more to the SA/12e than just quality parts and fortress-like build quality. The design thoroughness begins at turn-on, in which internal components are protected against surges by a controlled power-supply charge-up. To give you an idea of the initial current draw of these amplifiers, turning one of them on caused the line voltage to dip from 118 to 106V for an instant; with both amplifiers idling, the line voltage stabilized at about 114V—a 4V drop from the level sans Thresholds. The SA/12e, being fully class-A from input through to and including output stage, draws its…
There's more to the SA/12e than just quality parts and fortress-like build quality. The design thoroughness begins at turn-on, in which internal components are protected against surges by a controlled power-supply charge-up. To give you an idea of the initial current draw of these amplifiers, turning one of them on caused the line voltage to dip from 118 to 106V for an instant; with both amplifiers idling, the line voltage stabilized at about 114V—a 4V drop from the level sans Thresholds. The SA/12e, being fully class-A from input through to and including output stage, draws its…
Threshold also makes a point of the fact that their STASIS designs maintain a constant (and high) damping factor over the full audio band. Contributing to this is the lack of overall feedback and the elimination of the ubiquitous output inductor (between the final output stage and the output terminal) required in most conventional designs.
Sound
OK, so we know that the big Thresholds are built like tanks compared with the go-cart construction of more real-world (pricewise) amplifiers. Two questions must be answered here. Are they among the best amplifiers in the world? (They better…
Sidebar 1: Specifications
Description: Class-A monoblock power amplifier. Power output: 250Wpc (24dBW) continuous, 500W peak into 8 ohms (resistive or reactive) from 20Hz-20kHz at no more than 0.1% THD. Power bandwidth: DC to 100kHz. Slew rate: 50V/us. Output current capability: 70A continuous (200A peak). Input impedance: 50k ohms unbalanced, 600 ohms balanced. Noise: minimum -100dB, unweighted, against rated output.
Dimensions: 19" W by 8.72" H by 27.75" D. Weight: 130 lbs.
Price: $14,400/pair (1990); no longer available (2007). Approximate number of dealers: 75.
Manufacturer…
Sidebar 2: System
I used the SA/12es in a system consisting of the Oracle Delphi Mk.IV turntable with Oracle 345 arm and Dynavector XX-1L cartridge, Sony CDP-X77ES CD player used as a transport with coaxial link to an Esoteric D-2 D/A converter, Rowland Consonance preamp, and B&W 801 Matrix Series 2 loudspeakers (no LF equalizer used).
Interconnects were AudioQuest Lapis (with the exception of the coaxial CD transport to processor link, which was a garden variety but 75 ohm video cable); loudspeaker cables were AudioQuest Clear Hyperlitz (bi-wire pair). The preamp-to-power-…