Parasound Halo JC 1+ monoblock power amplifier Page 2

The bass guitar and kickdrum were reproduced with appropriate force and definition, though I felt I needed to remove the plugs from the Minos' upper ports to optimize the system's low-frequency reproduction. Mark Knopfler's vocalizing sounded clean and appropriately husky. But what really enthralled me about this atmospheric track was the depth of the soundstage. Some of the instruments had been mixed with various amounts of reverb. The piano that accompanies the acoustic guitar at the beginning before the verse, for example, was set way back in the soundstage, behind the voice and marimba. The tunnel of reverb behind the guitar power chords in the interlude stretched way back behind the speakers. The Parasounds nicely separated the soundstage's layers.

It is superb stereo productions like this that make me resistant to the "Back to Mono" movement—for me, space is the place! When producer Erick Lichte and I worked on this issue's Recording of the Month, Translations, performed by the Portland State Chamber Choir conducted by Ethan Sperry (16/44.1k FLAC files, Naxos 8.574124), we worked carefully to arrange the spatial elements of the performance to conform with composer Eriks Ešenvalds' intentions as indicated in the works' scores. With the Parasound driving not just the big Vimbergs but also the little KEFs, the various percussion instruments on track five, Vineta, which tells the tale of a city consumed by the Baltic Sea because of its citizens' hedonistic tendencies, were all precisely and stably positioned in space exactly where we had intended. The vibes at the beginning and the syncopated tubular bells at regular intervals, in particular, could be readily heard lighting up the vast acoustic of St. Mary's Catholic Church in Mount Angel, Oregon.

520para.2

The Parasound's high frequencies sounded more like what I experience from a good tube amplifier. Even with a recording having a somewhat forward balance, like Christian Tetzlaff performing the Beethoven Violin Concerto with Robin Ticciati conducting the Deutsches Symphonie-Orchester Berlin (24/48k FLAC, Ondine 1334), the Halo JC 1+ amplifiers neatly stepped out of the way of the music-making. (I have been a fan of Christian Tetzlaff since downloading his idiosyncratic recordings of the Brahms violin sonatas with pianist Lars Vogt—DSD128 files, Ondine ODE1284-2D/HDtracks). The Beethoven orchestra was reproduced with excellent depth, especially with the woodwinds, and the image of the violin was both stable and palpable. The manner in which the interplay between the solo violin and the timps in the first movement's cadenza was laid bare by the Parasounds and KEFs was gripping, yet without any feeling that the instruments were unnaturally spotlit.

Dynamics were, as you would expect from such a powerful amplifier, extraordinary. My long-term test track for dynamics is a recommendation from Erick Lichte, "Fit Song," from Cornelius's Sensuous: la musique de 21° siècle (ALAC files ripped from CD, Warner Japan EVE016). The drum samples on "Fit Song" were very cleanly recorded, and I could play them at ridiculously loud levels on the Vimberg speakers without there being any sense of strain. The drums remained behind the plane of the speakers where the synth and voice samples resided, despite the loudness. And while the bass drum crescendos on "Vineta" thundered out of the Vimbergs with the Parasounds, the slight amount of flanging on the bass guitar in Joan Armatrading's "Willow" (16/44.1k FLAC, Tidal) was a model of clarity. Low-frequency power and delicacy!

It was time to see how the new amplifier compared with the original JC 1s: No 38-year-old memories this time. Off I went to my storage space.

520para.ins

Compared with the Halo JC 1
Playing the old JC 1s driving the Vimberg speakers with the level matched with the 1kHz warble tone on Stereophile's Editor's Choice CD to what I had used to audition the new JC 1+s, it all got a little smaller. There was still plenty of low-frequency slam on the Cornelius track, still plenty of soundstage depth on "Vineta," still precise stereo imaging, and a tonal balance that was very similar to that of the new amplifier. But all a little smaller. While Joan Armatrading's haunting voice had the same slightly spitchy quality it had with the new amplifiers—that quality is characteristic of the recording, not the amplifiers—she was presented a touch more forward in the soundstage. The reverb tails of the damped tom-toms that punctate the song's chorus were shorter than I had gotten used to with the JC 1+s.

I followed Joan's "Willow" with Robert Silverman's performance of Schubert's six Moments Musicaux for piano (D.780) from Concert (CD, Stereophile STPH005-2). I had captured this album with a spaced pair of DPA 4006 microphones, so the stereo image is not as precise as is usually the case with my recordings. Even so, with the JC 1+ amplifiers, the feeling of listening to a Steinway D in a real space was very satisfying. And when a member of the audience makes a sound at the back of the hall halfway through the sixth Moment, a sound at the very back of the soundstage is what I heard. Changing to the JC 1s, while the piano's left-hand register still had good low-frequency weight, the image of the piano was closer, the hall a touch smaller, that audience noise slightly less palpable.

While I could live with the JC 1s, and have done so at times over the years, the sound of the new amplifiers had an oh-so-important edge.

520para.3

Compared with the Lamm M1.2 Reference
At $33,990/pair and offering 95W or 180W into 8 ohms, depending on its output-stage bias setting, this monoblock is more expensive and less powerful than the Parasound Halo JC 1+. But like the Parasound, it is heavily biased into partial class-A operation and its distortion is both very low and predominantly the subjectively innocuous second harmonic. The M1.2s have been in and out of my system since I reviewed them in April 2012. (At regular intervals I offer to return the amplifiers but, like Richard Schram, Vladimir Lamm continues to be okay with the long-term loan.) In my original review, I wrote that as well as the M1.2s being soundstaging champs, there was almost a "glow" to their sound that particularly enhanced mono recordings. Jim Austin basically agreed with me in December 2016: He wrote, "The Lamms didn't bring out every tiny nuance—a surprise, as I expect amps costing this much to do everything perfectly—but boy, are they musical!"

Over the years, while I remain impressed by the Lamms' soundstaging, that glow appears to be accompanied by a somewhat forward balance. Although the M1.2's gain was only a couple of dB higher than the Parasound's, with a high-sensitivity speaker like the Vimberg Mino, I can hear a slight hiss with my ear close to the tweeter, perhaps because I am still using the original input-stage tubes.

520para.ins2

Hiss there was none when I changed from the Lamms to the Parasounds. The soundstage remained deep and detailed, but everything within that stage moved a little farther back, with an increased delicacy to the sounds of individual acoustic objects. The M1.2's midrange was a bit more robust-sounding with both the Silverman and Armatrading tracks. Its low frequencies were richer than those of the Halo JC 1+; the Curl-designed amplifier exerted tighter control in the bass with the kickdrum on "Fit Song," which is why I unblocked the Minos' upper ports.

A close-run thing, for sure. With both the big Vimbergs and the little KEFs, I slightly preferred the presentation of the Parasounds on rock and jazz, that of the Lamms on piano and orchestral music.

Summing up
Michael Fremer concluded his review of the original Halo JC 1 by saying "There was nothing solid-state-sounding about the JC 1. . . . 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."

After several weeks auditioning the Parasound Halo JC 1+ monoblocks, I don't really have anything to add to what Mikey wrote in 2003, other than to note that even with its significant increase in price, the improvement in its sound quality and the explosion in recent years in the prices of high-end, high-power amplifiers keep the JC 1+ competitive. This is a superb-sounding amplifier that will get the best from every loudspeaker with which it is partnered. Well done, Mr. Curl.

COMPANY INFO
Parasound Products, Inc.
2250 McKinnon Ave.
San Francisco, CA 94124
(415) 397-7100
ARTICLE CONTENTS

COMMENTS
Bogolu Haranath's picture

May be JA1 could keep the JC1+ for a while (or, the Classe Delta monos), and review the new Magico A5 speakers :-) ........

Jim Austin's picture

I (JA2) was scheduled to review the A5 for our August issue, but when California was shut down, my review pair had not yet been built, so the review was postponed indefinitely.

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture

Hopefully, they could be built during the 3rd quarter ........ Hopefully, you (JA2) could review and publish that review before the end of the year ....... My guess is, they are worth the wait :-) .........

Jim Austin's picture

I await them eagerly. Meanwhile, I'll have to make do with the M2s I have here at the moment. :-)

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture

You could compare them to M2s and also, the Revel Salon2s :-) .......

Bogolu Haranath's picture

You (JA2) could do follow up review(s) of the JC1+ and/or the Classe Delta monos with M2s, while waiting for A5s :-) .........

Bogolu Haranath's picture

If you (JA2) do a follow-up review of JC1+, may be you could also do a review of the Parasound top model, JC2 BP pre-amp ($4,500) :-) .......

John Atkinson's picture
Bogolu Haranath wrote:
If you (JA2) do a follow-up review of JC1+, may be you could also do a review of the Parasound top model, JC2 BP pre-amp ($4,500) :-)

Kal Rubinson reviewed the Halo JC2 BP in 2011. See www.stereophile.com/content/music-round-47-page-3.

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

Thanks ...... I missed that review ....... JA2 could still do a follow-up review of JC2 BP with JC1+ :-) ........

Pritam's picture

Thanks for a great review, John - I thoroughly enjoyed reading your write up. I have had a few Parasound products over the years and currently own a P6 paired with a JC 5 power amp. The latter is the
best power amp I have ever owned and paired with a pair of Monitor Audio Gold 300s, the sound is sublime! I wonder how different a pair of JC 1+ would sound in my current system; anyway, Well done, Mr. Curl is all I want to say as well for delivering the JC 5 - simply a most fantastic amplifier. Someday maybe I will own pair of the the JC1 + :) ..
I must also say, that the Gentlemen I have had the pleasure to interact with at Parasound, mostly for
product knowledge and to leverage their general audio experience, are simply wonderful.

Ortofan's picture

... comparison with the JC 1+ a ~17-year-old unit?
If so, was any effort made to determine (as by measurement) whether or not its performance had deteriorated with time?
It's not inconceivable that a nearly 20-year-old amplifier might need to have certain parts (such as electrolytic capacitors) replaced.

It's also disconcerting to find out that Mr. Curl/Parasound decided to incorporate obsolete devices into a new/updated product offering. None of the companies I've worked for would tolerate such a situation. Obsolete parts are only to be inventoried for use as service spares, not for current production units.

Herb Reichert's picture

in what engineering realm does "no-longer-manufactured" mean "obsolete" ???

Why do you think so many great/legendary amp designer's stockpile these JFETs (and other extra-ordinary parts)?

https://www.stereophile.com/content/gramophone-dreams-26-nelson-pass-harmonic-distortion

hr

Bogolu Haranath's picture

Ortofan's 'weaponized adjectives' are mild compared to some others, on Stereophile website :-) .......

Ortofan's picture

... really HR? That characterization seems a tad extreme.

"No-longer-manufactured" means "obsolete" in every engineering "realm" I've been associated with for the past 40 years.
Just one example of the usage of that term:
https://www.analog.com/cpsearch/crossreferencesearch.aspx
Would you find the phrases "not for new design" or "end of life" less offensive?

Why do "so many great/legendary amp designer's stockpile these JFETs (and other extra-ordinary parts)?"
Likely because they would rather not go to the expense and effort required to find suitable replacement devices, redesign circuits and circuit boards as necessary, possibly reprogram the assembly equipment if automated assembly is used, update the documentation, get the products re-certified by regulatory agencies, and so on. Maybe the companies for which these "great/legendary amp designers" work don't have a sustaining engineering department whose function includes the redesign of existing products when certain components become "obsolete". For a relatively low volume application, making a "lifetime buy" of "obsolete" devices may be the more economical and expeditious route. However, that's never been considered an acceptable practice for any of electronic products with which I've ever been involved.

Bogolu Haranath's picture

JA1's review of Classe Delta monos is coming soon in Stereophile ....... May be JA1 describes how the new, more modern Classe, class-A amps are designed ...... and, how the Classe monos compare with JC1+, in sound quality :-) .......

Bogolu Haranath's picture

Some people take the 'don't mess with success' approach :-) .......

John Atkinson's picture
Ortofan wrote:
Why do "so many great/legendary amp designer's stockpile these JFETs (and other extra-ordinary parts)?" Likely because they would rather not go to the expense and effort required to find suitable replacement devices...

When I discussed the subject with the late Charley Hansen some years ago, the problem is that there weren't any replacement parts. Apparently the semiconductor fabs no longer manufacture high-performance but low-profit, complementary, small-signal J-FETS that get anywhere close to the performance of those used by Parasound, Ayre, and others. Charley therefore spent a very large sum buying up as much as he could afford of the world's supplies of these devices.

John Atkinson
Technical Editor, Stereophile

Ortofan's picture

... totally stymied if a favorite component becomes "unobtanium"? If they are, indeed, truly "great/legendary", shouldn't it be well within their capability to develop an alternate design that uses more readily available devices?

ROHM once made fabulous bipolar transistors, with exceptionally low base spreading resistance, that were ideal for a moving-coil cartridge phono preamp. In the days of CRT-type HDTV sets, Sanyo and Panasonic produced high-voltage transistors, with very low collector output capacitance, that were well suited for use in the driver stage of an audio power amp. Those specific parts are all gone and they're not coming back. Linear Systems presently makes some low-noise JFETs and Sanken makes some transistors for audio driver applications. Neither are necessarily drop-in replacements for "obsolete" devices, so some redesign effort could well be required to convert to their use. Marantz's Ken Ishiwata used to comment on the matter of staying on top of device obsolescence and identifying acceptable replacements, while performing redesigns, as needed.

I've seen more than one case where the last-time-buy didn't last a lifetime. Those involved took the easy (or lazy) way out and hoped that they would no longer be working at the same company - either because they had changed employers, retired or died - by the time that the "lifetime" supply was exhausted.

Again, it's disappointing to see that a decision was made to incorporate obsolete devices into a newly updated product offering - especially one that seems to be on a decades long life cycle. It's curious to note that some tube amp consumers, by comparison, seem to have no qualms about the use of new-old-stock/out-of-production parts. Maybe that trend is spreading into the solid-state "realm"?

CG's picture

Two comments:

1. There are precious few companies making JFETs these days. The market just isn't there. This is especially true for P-channel devices, which are harder to make with low noise properties. Most of the JFETs available now are based on decades old processes that have been kept alive for some high priority customers. That doesn't include the audiophile product business.

Linear Systems has really done yeoman's work in providing JFETs for specialized industries. At least in the JFET world relevant to this discussion, much of their activity has been to clone the Toshiba designs. It's hard, again especially for P-channel devices. Toshiba had the process knocked, and produced them by the freight car load. There was that much demand and the prices were quite literally pennies per transistor. Linear Systems doesn't have that available market, so the prices are inevitably going to be much higher, both due to basic economics and the yield challenges. (You make a zillion devices and you learn the subtleties of the recipe.)

The trend now is for entire systems to be built into a single chip. That's where the money is. If a company gets a design win for a single cell phone audio system, that's bigger for that semiconductor company than if they got every sale of every semiconductor for the entire specialty audio market. By a large factor.

Something to consider...

2. Along the same lines, consider the age demographic of the guys (it's almost exclusively men) who are doing analog design for audio. It pretty much parallels the age demographic of the people who buy the finished product. What will happen when they decide to retire?

When I was in college, at your basic nerd school, it seemed like every EE major wanted to go into the audio business. Of the entire student body when I was there, as far as I know a total of three did go into the audio business. They all were management engineering majors, and the three focused on the business subjects that were part of that curriculum.

With the consolidation of system functions onto a single chip, that means that far fewer analog design guys are needed. That's been the trend for a while. The semiconductor providers also do much of the design work so that their customers don't need many analog design guys, not only for audio but for any analog application. That's probably a good thing, in a way, since the young people studying electrical engineering mostly aren't all that interested in analog or RF design. It's the circle of supply and demand.

Something else to consider...

Bogolu Haranath's picture

Five to ten years from now, all audio amplifiers are gonna be class-D ...... Five to ten years from now, people will be listening to wireless speakers with built-in class-D amps, in addition to various Bluetooth devices :-) .........

TJ's picture

Thanks CG, nice points

CG's picture

Dunno!

If you're paranoid enough, you could make the same arguments about bipolar output devices suitable for audio use, too. And a bunch of the other parts. Maybe that's not paranoia - just being realistic. I bet the tube guys had similar thoughts back in the boom days of tube based amplifiers.

In any case, if there's nobody interested in designing new gear, it won't matter, will it?

Ortofan's picture

... is that many (small-signal, and even medium power) devices, that were once available in leaded/through-hole packages, may now only be produced in surface-mount packages. Aside from the need to create new circuit board layouts and have SMT/SMD assembly capability, certain audio companies would have us believe that leaded/through-hole parts are "good" and that surface-mount parts are "bad".

If those companies have no choice other than to switch to using at least some surface-mount parts, then they would need to retract their previous assertions about the alleged inferiority of surface-mount technology.

CG's picture

I'm not sure that is accurate.

Many audio companies have already switched to surface mount semiconductors where the package is available.

The problem has to do with some of the passive components. There just isn't the ready availability of film caps in the varieties found with through hole components. Some will likely never be available in surface mount packages due to not only the size, but also the thermal constraints during surface mount soldering. Also, there is far less of a selection of low noise, low distortion resistors in surface mount packages. (Bruce Hofer, who certainly can be considered an expert on the topic, has written about this.) That inferiority is not "alleged"..

So, companies are then left with the choice of sonic compromise or to use mixed manufacturing technologies. Combining both surface mount and through hole components on the same printed circuit board assemblies can certainly be done, but it costs more. I'm sure audio companies would like to save money where they can, IF it gave them the same or better results.

Ortofan's picture

... quite adequate, unless you want to specify a particular boutique brand of capacitor in order to help validate your creation or lend it a certain cachet in the marketplace.

Likewise, for resistors, unless perhaps you're in the business of building test equipment. Funny how the tube amp makers all seemed to manage when resistors were mostly of the carbon composition type.

CG's picture

Well...

You are certainly entitled to your opinion on this. I disagree. Try finding polystyrene caps in surface mount. Not so easy. These types of caps have been measured to provide lower distortion in many circuit locations.

In general, I've noticed from you a certain hostility toward everybody in what I'll call the high performance audio business. This is shown in almost all of your posts. Again, you are completely entitled to your own thoughts on the business and the people who work in it.

This is not a good discussion. I hope you don't take offense when I decline to respond further.

JHL's picture

Well said.

Ortofan's picture

... to the function of your design, or might PPS type capacitors - available in SMT for from WIMA and Panasonic, to name two - be satisfactory?

Over 30 years ago, Hafler introduced the XL-280 power amplifier and claimed that it had the lowest residual according to a bypass test. To my knowledge, no one has ever stepped up to challenge that claim. The XL-280 accomplished that feat without resorting to the use of any exotic components. If an output capability of about 160W@8Ω/225W@4Ω was insufficient, there was the more powerful XL-600. An XL-600 would clip at about 370W, 680W and 900W into 8Ω, 4Ω and 2Ω, respectively. The XL-600 sold for $1,200 - or about $2,800 as adjusted for inflation today.

Similarly, QUAD has been producing its "straight wire with gain" amps for decades with out using exotic parts, either.

Essentially, do you want your amplifier to exhibit a certain subjective sound quality, or do you want it to be as neutral and self-effacing as possible? If you want a neutral amp, then it's been demonstrated that the use of exotic types of components is not a requirement to achieve that goal.

Bogolu Haranath's picture

Probably, the Benchmark AHB2 is similar in concept, as those Hafler amplifiers :-) ..........

Bogolu Haranath's picture

The new Hafler company still makes power amps ........ See, their website for details :-) .........

Bogolu Haranath's picture

Ortofan, Rotel says, in their Michi amps they use 'patented slit foil, low ESR capacitors' ........ Do you know anything about them? :-) .......

Ortofan's picture

... slit-foil type electrolytic capacitors for quite some time.
You can read about the technology here:
http://www.dnm.co.uk/capacitors.html

The slit-foil caps were originally sourced from BHC, which was acquired by Vishay/Kemet. Kemet still offers some parts of that type:
https://content.kemet.com/datasheets/KEM_A4029_ALC10S.pdf
https://sh.kemet.com/Lists/ProductCatalog/Attachments/632/KEM_A4030_ALN20S.pdf

According to the DNM site, the slit-foil caps may also be available from Taiwanese company Supertech:
http://www.supertech-elec.com.tw/electronic/ECAPS/Audio-2T.htm
http://www.supertech-elec.com.tw/electronic/ECAPS/Audio-4TTN.htm

DaveinSM's picture

That total capacitance figure of 22,400 on page 1 sure seems low. Are you sure it’s not 224,000?

abraxalito's picture

The 22,400uF is the figure for the input stage supply. The output stage presumably has much more.

Ortofan's picture

... output stage.

DaveinSM's picture

Still, how odd. You really don’t see the output stage capacitance specified very often. I’m sure that a 22,400uf rating is impressive, but I’m more interested in comparing apples to apples. The total capacitance is a much more meaningful figure to me for a high power, high current solid state power amp such as this one. Yet it’s nowhere to be found in the review.

Bogolu Haranath's picture

Parasound website provides various technical details of JC1+, including capacitance and current output capabilities :-) ..........

Pryso's picture

I owned a pair from about 2006 to 2019 and used them with two different highly regarded speaker systems. No other amp delivered as much musical enjoyment as the JC1s with either speaker. I utilized the low bias setting for background music and hi bias for active listening. Heat was never an issue.

The only reason I no longer own them is because they have far more power than now needed, plus at my age they were becoming a little heavy whenever I needed to move them. I can only imagine the new model must be exceptional.

TJ's picture

Thanks John, great review. Any thoughts about how the SQ compares to your Pass Labs XA60.8 amps?

Jim Austin's picture

Any thoughts about how the SQ compares to your Pass Labs XA60.8 amps?

JA1 doesn't have the XA60.8s. JA2 does.

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture

Which begs the question, 'any thoughts about how the SQ compares to your Pass labs XA60.8 amps' JA2? :-) ..........

Jim Austin's picture

Regrettably, I haven't had the opportunity to hear the JC 1+. Hopefully I will at some point in the reasonably near future.

Jim Austin, Editor
Stereophile

TJ's picture

at the same price but much lower weight

Bogolu Haranath's picture

Bridged AHB2s cost less than Pass XA60.8 or JC1+ :-) ........

TJ's picture

yes a lot less, I was thinking of the JC5

Bogolu Haranath's picture

Comparison between bridged AHB2s and JC5 would be interesting :-) .......

georgehifi's picture

Probably better than any other $17k amp/s around.

Cheers George

michelesurdi's picture

an exemplary review.when shall we see its like again?

georgehifi's picture

Not if Class-D and the environment has anything to do with it.
Maybe the Technics SE-R1 had a shot?

(Bit like exotic V8 V10 V12 muscle cars) I'm now driving a 2lt twin turbo buzz box, JUST NOT THE SAME!!!

Cheers George

Bogolu Haranath's picture

You can still buy a V8 Mustang, Camaro and Corvette :-) .........

georgehifi's picture

In Australia that'll cost you a kidney a lung and left testicle. $$$$$$$$$$.

Cheers George

Bogolu Haranath's picture

So, in Australia, if some one wants to buy an Aston Martin Vanquish or Lamborghini Aventador with V12 engines, that would cost them both kidneys, both lungs and both testicles :-) .......

georgehifi's picture

And if you want the Veneno Roadster, your body and soul is the price.
https://cdn.motor1.com/images/mgl/A80qL/s1/2014-lamborghini-veneno-roads...

Bogolu Haranath's picture

Poison ......

Venenosaurus :-) .......

Bogolu Haranath's picture

Armando the racing pigeon sold for $1.4 million in 2019 :-) ..........

georgehifi's picture

Nothing a BB gun wouldn't take care of.

David Harper's picture

All box speakers with dynamic drivers in them have distortion levels at least ten times that of any power amp. Therefore it is impossible to hear amplifier distortion thru this type of speaker. The amp's distortion is completely masked by the much greater speaker distortion. This is why discussions about the "sound quality" of amps are absurd. What these reviewers are actually hearing are the speakers, not the amp.

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