Electrostatic loudspeakers (ESLs) have always held a fascination for audiophiles. The Jantszen, Beveridge, KLH, Acoustat, Stax ESL-F81s, and Servo-Static models in the late 1960s and '70s, as well as the MartinLogans and Sound Labs of today, all promise faster transient response, low distortion, and a higher order of "transparency." Why? The driver, instead of being a cone with a mass of several ounces, is an extremely thin sheet weighing mere grams, often made of Mylar, and suspended between two charged…
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Larry Greenhill reviewed the Quad ESL-63 US Monitor in February 1989 (Vol.12 No.2):
This inability to play loud turned out to be related to an altitude effect, the speaker being unable to play any louder than 97dB at the 7000' Santa Fe elevation (still, the original '63s were no rock loudspeaker, even at sea level). Stands (Arcicis, sand-filled to reduce vibration and increase stability), subwoofers (perhaps Celestion System 6000 dual-mono subwoofers), and tube amps (Futtermans) were recommended associated components for the owner willing to go the full route.
Then came the next period in the life of the Quad ESL-63—modifications and improvements. Some were done by Quad…
The US Monitor stayed very close to the sound of the my early '63s for most vinyl recordings and CDs. The new speakers played louder than my originals, and there was an enhanced openness, particularly in the upper midrange. In addition, the amplifiers continued playing as I cranked up the volume control (my older Quads would shut down just as the amplifier's protection circuits or fuses acted). By comparison, my older ESL-63s had a "dark" tonality. In many respects, the "intact" US Monitor (with its metal screens on) sounded like the older Quad with the screens off (footnote 1). As a result…
Sam Tellig's final comments on the Quad ESL-63 appeared in June 1989 (Vol.12 No.6):
Remember Fred?
Not Fred Yando, of Quad USA. But FRED as in Full-Range Electrostatic Dipole—the now venerable Quad ESL-63, available in its new US Monitor version.
This is my third pair of ESL-63s—a very early pair, followed by a later pair, and now the new ESL-63 US Monitor. I guess I am a creature of habit. I've been married to these speakers now for seven years. And married to Mrs. Audio Anarchist now for 25.
"You're getting another pair of Quads," shrieked one of the Thursday…
Sidebar 1: Specifications
Description: Full-range electrostatic speaker system. Power capacity: 100W, 10V rms, 40V peak maximum signal input. Nominal impedance: 8 ohms (6.2 ohms minimum). Sensitivity: 86dB SPL for 2.83V rms at 1 meter.
Dimensions: 36" H by 26" W by 6" D (base 10" D).
Serial numbers of review samples: 13,955 & 13,956, 1984.
Price: $2850/pair, 1983-1985; $3990/pair, 1989. Approximate number of dealers: 50.
Manufacturer (2001): Quad Electroacoustics Ltd., IAG House, Sovereign Court, Ermine Business Park, Huntingdon, Cambs PE29 6XU, England. Tel: (44) (0)845-…
Sidebar 2: Measurements (from June 1989, Vol.12 No.6)
As I had dragged my motley collection of test equipment (footnote 1) over to Larry Archibald's listening room to carry out a set of measurements on the Mirage M1 loudspeaker he has reviewed elsewhere in this issue, I thought it might be a good idea to quickly take a look at the measured performances of the latest, "US Monitor" version of the $3995/pair Quad ESL-63, which had so impressed Larry Greenhill in February (Vol.12 No.2). Sam Tellig also writes about the Quad in this month's "Audio Anarchist" column, and the particular sample…
Sidebar 3: The Arcici Quad Stands (from January 1987, Vol.10 No.1)
The Arcici stands came at the right time in my life—just as I decided to forget about the Martin-Logan CLS and Apogee Caliper to stay with ESL-63s. I had been offered a pair of the Chicago Speaker Stand Quad stands for audition, but wasn't impressed by what I saw (I didn't have much chance to hear them). Most important, the Chicago stands don't significantly add anything to make the speakers' frames more rigid, which is what ESL-63s really need. Moreover, filling the CSS stands with sand or lead shot—as recommended—makes…
Such is the pace of development in digital technology these days that it is hard not to become convinced that digital playback is a solved problem. The measured performance aberrations are so low in absolute level—and, more important, so low compared with the typical threshold of human hearing—that it is difficult to see why digital components should sound different from one another.
Yet my experience and that of Stereophile's reviewers has been that, yes, they still sound different. What has happened is that the cost of owning a state-of-the-art CD-playback component has…
All the circuitry is realized using Xilinx FPGA chips. The DSP programming is stored on an EPROM chip, so future updates are possible. With all its processing horsepower, the DAC64 runs very hot; make sure you give it plenty of ventilation.
Speed bumps
In auditioning modern digital components, there are times when I begin to doubt whether there are any differences to be heard. This was not the case when I began auditioning the first sample of the Chord DAC64, using the Mark Levinson No.31.5 CD transport and with the Chord's RAM buffer switched out. Not only was the sound hard-edged…
Comparisons
Given the pace of development in digital technology referred to earlier, making value judgments of the quality of a digital processor in isolation is impossible (provided it doesn't drive you out of the room). I therefore set up comparisons with some of the components that have passed through my listening room in recent months. In each case but one, the transport used was the Mark Levinson No.31.5, connected with identical AudioQuest CinemaQuest SVD-4 S/PDIF datalinks (footnote 1), and levels were matched at 1kHz to within 0.1dB using the Levinson No.380S preamplifier's…
Given the pace of development in digital technology referred to earlier, making value judgments of the quality of a digital processor in isolation is impossible (provided it doesn't drive you out of the room). I therefore set up comparisons with some of the components that have passed through my listening room in recent months. In each case but one, the transport used was the Mark Levinson No.31.5, connected with identical AudioQuest CinemaQuest SVD-4 S/PDIF datalinks (footnote 1), and levels were matched at 1kHz to within 0.1dB using the Levinson No.380S preamplifier's…