Parasound Halo JC 1 monoblock power amplifier Page 4

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 Waters' Folksinger (Classic), Beethoven's Piano Concerto 3 (Ashkenazy/Solti/CSO), the 45rpm edition of Bill Evans' Waltz for Debby (Analogue Productions), and other discs I'd particularly enjoyed during the review period.

The presentation was much different, and quite instructive. The Nu-Vista 300's overall presentation was bigger—bigger images on a more expansive soundstage—but the JC 1s' was more finely featured, more refined, and clearly more transparent—I could "see" farther into the soundstage. Images sounded smoother and less mechanical, and therefore somewhat more convincing.

My conclusion following the switch? The improved resolution of low-level detail, macrodynamic texturing, and transient and sibilant suaveness were almost all the JC 1's doing. I thought I could now more clearly hear the subtle midbass warming effect of the nuvistor tube's insertion in the Nu-Vista 300's signal path. The midrange wasn't thin; the midbass was a bit pronounced. There also seemed to be a bit of spotlighting in the very top end, which nicely complemented the midbass.

The JC 1's bottom end had slightly greater extension and clearly more focus—not that the Nu-Vista 300 sounds lightweight or unfocused! The JC 1 clearly trumped the Nu-Vista 300 in terms of transient speed and clarity—one of the factors giving the former a smoother, more refined sound.

Which was "better" overall? I don't know. I enjoyed listening to both. The Nu-Vista had a richer, bigger, more dramatic presentation; the JC 1's was smoother, more controlled, more organized.

Just to be sure that some kind of cable interaction wasn't skewing these results, I put my reference Harmonic Technology Pro-Silway II interconnect and Magic Woofer speaker cable on the Audio Dharma Cable Cooker to warm up for a day, and then into the system. I was surprised by a slight loss of transparency and a slight coarsening of the very top end compared to the Analysis Plus, which costs far less. I removed the Shunyata Hydra power distributor from the system and plugged the amps directly into the wall. The sound got less coherent and even coarser, so back in the Hydra went. Whatever it is and whatever it does, that thing really works.

With the JC 1s back in the system for one last go-round, I got the same results comparing cables and listening with and without the Hydra. For now, I'm not sure what to make of this, but, as they say on Fox News, "We report, you decide" (except that I really mean it). I may switch reference cables, but I'm not sure yet. As for switching amps, had I not already owned the Nu-Vista 300 and had to choose between it and the JC 1s, I'd have had a difficult time deciding. But whether it's the novelty or whether they're genuinely more refined, neutral, and revealing, I'd probably go for the JC 1s. Hardly the results I expected when I unboxed them!

Measured performance doesn't always correlate with actual sound, but in this case, assuming the Parasound Halo JC 1's published specs resemble what John Atkinson measures, there's a strong connection. The specs show ultra-wide bandwidth, high-current capability, low, low noise, a high signal/noise ratio, and a fast slew rate, among many other indicators of outstanding amplifier performance.

That's what I heard. There was nothing solid-state-sounding about the JC 1—either on top, where it was anything but "hard" or "etched," or on bottom, where it didn't serve up one-note, overdamped bass. If the Halo JC 1 committed any sonic errors, they were on the subtractive side and easily missed. Perhaps some listeners will find the JC 1 too refined and perhaps a tad polite, but I didn't.

There was an honesty to the overall tonal and harmonic presentation that transcended technological stereotypes. Powerful, refined, smooth, organized, dynamic, transparent, and rhythmically supple, the JC 1 offered a combination of attributes that added up to many weeks of listening pleasure. I'd be happy to have it go on indefinitely—as, no doubt, will many of you. If you need to spend more than $6000 for 800W of stereo amplification, by all means do so, but I'm not sure you'll get much more measured or audible performance—or pleasure—than what Parasound's superbly built Halo JC 1s delivered. A bargain, and highly recommended.

950 Battery St.
San Francisco, CA 94111
(415) 397-7100

James Trower's picture

Parasound JC1 power amplifier comparison to the newer Parasound JC1+ power amplifier.

I have owned many amplifiers over the years; I am saying 30 or more. I have had small 75 watt amps to much more powerful 500 watt amplifiers.
I bought the JC1 amplifiers in 2004. I had read many positive reviews such as this one in Stereophile.
Upon a few weeks of listening; I honestly thought there was a problem with them. The bass was so deep, and textured, I thought something was amiss.
The dynamic swings were on a level that shocked me. The ability to go to very high volume levels, without sounding like the volume had changed. They just would not distort at ridiculously high levels.
The bass issue still bothered me. I thought part of the circuitry had malfunctioned, and was causing bass that did not exist in the music. It just seemed too present, deep and growly.
I changed speakers, as I have no tone controls in my system. The same; just amazing dynamics, crystal clear high volume levels and truly amazing bass.
It took me a bit. It was the fact the JC1's provided a huge amount of current.
I had also read many reviews stating the bass was phenomenal. I was satisfied they were not malfunctioning.
I did quite a few comparisons to amplifiers reviewed and bench tested in Stereophile. I found that the maximum dynamic output of this amp is hard to beat by any amplifier tested.
Then came the review of the new Parasound JC1+. The bench test measurements for the JC1+, even though it is rated at 450/Watts (50 more than the JC1), showed quite a bit less maximum power into 8/4 and 2 ohms.
The maximum power output was:
The JC1 - 8/4/2 ohms power output was 586/1154/2255 and 4200 watts into 1 ohm.
The JC1+ - 8/4/2 ohms power output was 500/830/1200 and no testing into 1 ohm.
I think this very high output from the Parasound JC1 was responsible for the exceptionally deep base and very large swings in dynamics. I think it also has very amazing detail and imaging.
If you can find a pair (usually around $5000) grab them. They get an A rating from me on my 20 year listening quest.