Setup and Use
In its unusually detailed instruction manual, Parasound recommends using the Halo JC 1 in balanced configuration. But my Hovland HP-100 preamplifier is single-ended, so that's how I used the Halos, with their Bias Level switches set to High, which configures the amp's output stage to operate at up to 25W in class-A. I placed the JC 1s on a pair of Finite Elemente Pagode amplifier stands and plugged them into the Shunyata Research Hydra power distribution center with Anaconda AvX power cord. I used both Harmonic Technology Fantasy 10 and Wireworld Silver Electra AC cords.…
search
On Jones' spare, languid arrangement of Hank Williams' "Cold Cold Heart"—just her piano, acoustic bass, and a sprinkle of percussive accents on electric guitar—the picture was so cleanly and exquisitely drawn that I found myself playing it again and again, even though such repeats don't give the grooves a chance to cool down and almost certainly cause damage. (Can I have another copy, Hobson?)
Admittedly, the insertion of the SME 30 turntable added an unknown variable to the mix. The only way to discern the JC 1's contribution to the super sound I was getting was to put my reference…
As I switched out the amps, I tried to sum up the experience I'd just had: I wondered whether the JC 1s or the other changes—or a combination of all of them—were responsible for the phenomenal transparency, resolution of low-level detail, and overall tonal neutrality I'd been hearing. More than that, the system was unusually "at ease"—a quality that kept me listening long into many nights.
A day-long warmup preceded any serious listening. In fact, I purposely stayed out of the room while the system played. Next evening, I played Norah Jones, Sibelius, Zombies, the Quiex SV-P of Muddy…
Sidebar 1: Specifications
Description: Solid-state monoblock power amplifier. Maximum output power (20Hz-20kHz): 400W into 8 ohms (26dBW), 800W into 4 ohms (26dBW) "continuous"; 1200Wpc into 2 ohms (23.6dBW) "short term." Class-A power, 25W into 8 ohms (14dBW); bias set to Low: 10W into 8 ohms (10dBW). Frequency response: 2Hz-120kHz, +0/-3dB. THD: <0.15% at full power, <0.018% at typical levels. IM distortion: <0.03%. Input impedance: 100k ohms. Input sensitivity: unbalanced, 1V for 28.28V output into 8 ohms (100W); balanced, 1V per leg for 28.28V output at 8 ohms.
Dimensions…
Sidebar 2: Associated Equipment
Analog sources: Simon Yorke, Nottingham Audio Annalog, SME 30/2 turntables; Graham 2.2, Immedia RPM2 tonearms; Lyra Helikon SL and Helikon mono, Transfiguration Temper Supreme, Lyra Titan (prototype), Audio Tekne MC-6310, Sumiko Celebration cartridges.
Digital sources: Musical Fidelity Nu-Vista 3D CD player & Tri-Vista SACD player.
Preamplifiers: Hovland HP-100; Manley Steelhead.
Power amplifiers: Musical Fidelity Nu-Vista 300.
Loudspeakers: Kharma Midi-Grand Ceramique 1.0, Audio Physic Avanti III.
Cables: Phono: Hovland Music Groove,…
Sidebar 3: Measurements
Before I performed any measurements, I ran the big Parasound Halo at one-third power into 8 ohms for an hour, after which the heatsinks were way too hot to touch. I had one mishap: Before I measure anything, I experiment with the grounding between the amplifier under test, the AC supply, and the Audio Precision System One test setup, in order to reduce power-supply spuriae to their lowest level. With balanced drive, there were no problems. However, after I'd performed a full set of balanced tests, I hooked up an unbalanced connection and again started to…
I love a simple tweak—one so elegant that I bang my forehead in recognition, moaning "Why didn't I think of that?!"
Such as this little gem for smoothing out the bass and getting rid of those lumps down below. I must credit this one to Victor Tiscareno, he of Red Rose/AudioPrism, out Washington State way.
"Jonathan," he e-mailed me, "I have a simple tweak that may work for some people, and for some it won't." Victor's a forthright guy. "Most of us loony audiophiles have a pair of speakers that are not in use, hanging around the house like albatrosses," he went on. "So here's a…
Not only is it possible for a thinking person to now and then drastically change his point of view, if for no other reason than the sake of change—if one wishes to prevent self-seriousness and various other forms of mental decay, it's probably an outright must. So it was that I recently began to wonder if everything I know about record players might be wrong.
Some background: Because I didn't stumble on the whole perfectionist audio scene until 1979 or so, and because I'd already built a decent record collection by that time, I was an easy convert to the gospel of Rega and Linn…
The TD 124's platter is switched on and off with the same crow's-head knob that selects between the four basic speeds (78, 45, 331/3, and 16rpm). At the center of the knob is a fine-speed control, for slight changes in pitch, the workings of which are downright ingenious: A crescent-shaped permanent magnet sits adjacent to the idler pulley, and within the underside of the pulley is a magnetically permeable reflector that pivots slightly and slowly as the pitch control is turned. The position of the reflector determines how much of an Eddy effect (see "Listening" columns passim) the magnet…
The Complete Guide to High-End Audio
by Robert Harley
450+xxiv pp., $29.95 softcover, $39.95 signed hardcover. Published by Acapella Publishing, P.O. Box 80805, Albuquerque, NM 87198-0805. Credit-card orders: (800) 848-5099.
by Robert Harley
450+xxiv pp., $29.95 softcover, $39.95 signed hardcover. Published by Acapella Publishing, P.O. Box 80805, Albuquerque, NM 87198-0805. Credit-card orders: (800) 848-5099.
When Robert Harley's book, The Complete Guide to High-End Audio, was published, I had a pretty puzzle facing me: Should Stereophile review a book written by one of its three (J. Gordon Holt, Thomas J. Norton, and Robert Harley) full-time equipment reviewers? Ultimately, I decided that we should publish a review. To get opinions of the book from the two ends…