Parasound's New JC3+ MM/MC Phono Preamplifier Offers Feature and Sound Refinement

Parasound's new $2995 JC3+ is a significantly upgraded version of the already high performance original JC3 phono preamplifier, though outwardly it looks identical to the handsome original.

According to Parasound’s Richard Schram, the original JC3’s design began as a phono preamp retrofit for the JC2 line stage with separate small circuit boards for each channel. The smaller the better, he said to reject noise that larger antenna-like copper traces would attract.

Designer John Curl decided to keep the circuitry simple, choosing purity over adjustability. Therefore the original JC3’s MC loading was limited to either 100 ohms or 47kohms, with 47k also for the MM input.

Curl believed then and I’m sure continues to believe that the vast majority of MC cartridges are suited for 100 ohm loading and I concur. The original JC3 featured custom made gold-on-silver contact NKK selector switches for the choice of 47K or 100 ohms. For Curl, low noise trumped loading flexibility and he wanted to avoid the noise added by potentiometers.

Schram understood that the loading limitation might lose a few customers but he let Curl call the shots. Why would he do that? For you youngsters, let me quote the late Stereophile founder J. Gordon Holt from 1988: “Few people in the audio business would deny that John Curl is an audio design genius—arguably the greatest one of our generation. He designed and built the electronics for Mobile Fidelity's SuperMaster and David Wilson's (of Wilson Audio) UltraMaster tape recorders, two of the three best analog recorders in the world. (The other is Keith Johnson's home-brew unit.) He designed the JC-1 head amp and JC-2 preamplifier sold under the Mark Levinson name some years ago….”.

However as we all know the customer is always right even when wrong and customers demanded greater loading flexibility. So Curl and circuit board designer Carl Thompson set about finding a way to include variable load impedance adjustability but only if the arrangement met certain stringent performance requirements and used Vishay low noise resistors.

Unfortunately, no Vishays met the specific requirements but the company agreed to develop and manufacture in small quantities for Parasound the appropriate part, which is a special low noise, dual-gang 50-550 ohm potentiometer. So the new JC3+ offers on the back panel a switch that fixes loading at 47k for MC or via the potentiometer variable 50-550 ohm loading, as well as 47K MM loading.

While the designers were at it, they made other improvements to the new edition including narrowing the spectrum of Johnson/Nyquist (thermal) noise in the input loading stage's resistor in order to maximize its low noise capabilities and further tweaking the phono module board to include 24 karat gold plated traces where each part is soldered, which Parasound claims provides "unprecedented transparency and musical detail".

MC S/N ratio has been improved from 75dB to 87dB, A-weighted. That is a very large S/N improvement! MM gain has been increased 1dB from 47dB to 48dB while MC gain has been lowered from 68dB to 64dB to prevent possible line stage overload when using high output MC cartridges. 64dB should be sufficient for virtually all MC cartridges.

The JC3+ power supply has also undergone a significant upgrade with 47% larger low-ESR power supply filter capacitors for greater current reserves and what the company claims are "head-snapping" dynamics. You have been warned. A new 82% larger R-core power transformer provides greater reserves for low-end impact that the company says is "beyond imagination", so please don't try imagining this at home, especially if you are alone.

To gild the illumination lily, at the behest of the few, the finicky and the fanatic, the front panel's illuminated "P" logo can now be switched off via a back panel switch.

When I reviewed the original JC3 Schram said its passive RIAA EQ parts are identical to those used in the Vendetta ($3000 in 1992). The active circuit uses very low noise parts chosen both for noise levels and for noise spectra, which Schram says is critical to how we perceive noise. The circuit is DC servo fully direct coupled with no coupling caps in the signal path and the output stage is a true dual differential balanced design. The output is either single ended via RCA jacks or balanced XLR.

Two low carbon steel partitions isolate the transformer from the phono circuit modules. The power supply also implements a large inductor and ultra fast/soft recovery diodes among other components. Each gain/EQ module is housed in its own extruded aluminum enclosure and the JC3+ includes a built-in AC line conditioner as well as an AC polarity invert switch that can be useful in eliminating phono hum.

Finally, there’s a front panel “mono” switch that activates relays within each module. When set for “stereo” the signal remains within each extruded housing. The signals meet each other outside the shielded housing only in “mono” mode.

JC3+ Sound

I reviewed the original JC3 a few years ago and didn’t have one around to compare to the new JC3+ so I can’t offer a sonic comparison. If you own the original should you upgrade to the new one? Again, I can’t answer that one for you but I’d say “no” unless you are thoroughly unhappy with the 100 ohm loading.

I ended up at 100 ohms for the Lyra Etna (4.2 ohm internal impedance) but closer to 50ohms for the Ortofon Anna (6 ohm internal impedance) and the Transfiguration Proteus (1 ohm internal impedance). Though 100 ohms for all still sounded more than acceptable to my ears.

Even using the ultra low output Anna and Proteus, the JC3+ proved subjectively to be a very quiet phono preamp. The quiet helps produce wide dynamics and high resolution of low level information. In terms of low noise, the JC3+ sounds (or doesn’t sound) like a far more costly phono preamplifier.

A lack of noise doesn’t just mean quieter or blacker backgrounds. The quieter the background, the greater will be the enhancement of image three-dimensionality and instrumental textures. The information added because of the lower noise floor doesn’t appear as separate information. Rather it gets added to and enhances the higher in level information. In that regard, the JC3+ performed well above its price point.

While the JC3+’s bass was tight, well-defined and punchy (producing excellent rhythm’n’pacing as they call it in Stereophile), it couldn’t produce the explosiveness and depth charge bombs (authoritative, fully extended bass if you prefer) thrown by more costly phono preamplifiers most of which incorporate large, massive often outboard power supplies.

Unless your speakers are full range, you’re not likely to have an issue with this because the JC3+’s lower midbass attack both timbrally and texturally was so well defined you won’t miss what you don’t get.

Drop in a far more costly phono preamp like PBN’s $22,000 Olympia PXi (review coming soon) and the bass weight, control and dynamics are the first things you notice. It can be powerful and dramatic when it hits you. Through that costly preamp you really do get the head snap Parasound promises!

While auditioning it I played Roland Kirk’s version of “Alfie” played on what sounds like a baritone sax. When Kirk slams the opening note, your head does snap back! Less so through the JC3+, but I take Parasound at its word that the + version does produce improved dynamics.

But back in the real world where even $2995 is a lot of money, had you gone to the great expense of buying speakers that could really express ultra-wide dynamics and full low frequency extension, you’d likely be spending a great deal more than $2995 on a phono preamp.

Sometimes I wish I could be a young, inexperienced reviewer with a modest system and gone from a matchbox sized under $1000 phono preamp to the JC3+ because I know what such a switch would elicit in terms of reviewer enthusiasm, superlatives production, etc. The JC3+ really deserved it for what it offers at its price point.

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

COMMENTS
Ortofan's picture

Still no subsonic filter?

This product must be intended for customers who only play perfectly flat records, don't have truly full range speakers and/or have plenty of amplifier power to waste.

et88b's picture

What price would you consider to be a real world system?

Michael Fremer's picture

My phono pre lacks one too. Few have them....

Ortofan's picture

...evidently because their designers don't live in the real world or they never bother to learn.

50 years ago, Bud Fried recognized the need for bandwidth limiting in amplifiers used with wideband speakers - including a subsonic filter in the phono preamp.

Quoting Tomlinson Holman (from 40 years ago): "An often overlooked and important area of preamplifier design is the amplifier’s infrasonic response..." The full text is available here: http://www.davidreaton.com/pdfs/holman_aes_paper.pdf

Michael Fremer's picture

I don't find such a filter necessary.

Ortofan's picture

Do you have any test records with spot frequency (not swept) test tones, such as those CBS used to produce?

Play one using a preamp with a switchable subsonic filter (with at least a third order - 18dB/octave response). Measure the IM distortion at the output of your speakers (or just listen for any difference) with the filter in and out of circuit.  Also, compare the peak power output of your amplifier with and without the filter.

Speaking of gurus, if Holman's work doesn't impress you, how about Rich Maez? His phono preamp design incorporates a 3-pole subsonic filter and you seem to have liked the unit's performance when you reviewed it.

sharris55's picture

Well I decided to wait for the JC3+ once I heard the details of the enhancements so did not purchase the JC3 after your first review.  Hard to tell from this article whether you heard any real gains (too bad the original JC3 had left the building).  After a nearly 8 month wait mine arrived in January.  During those 8 months I had bided my time with one of Parasound's zPhono preamps.  Needless to say the difference was startling.  I have yet to play with the settings. I think we are set on 50 ohms right now and everyone seems to have a different rule of thumb when it comes to adjusting it.  My retailer says the vinyl sounds so good right now he hates to even mess with it.  One thing I am not used to is having a power switch on the phono preamp...keep forgetting and leaving the thing on overnight.  Those Living Stereo titles keep rolling in and I simply ENJOY.

Michael Fremer's picture

Idling it doesn't use much juice. I'd just leave it on...

Samurai7595's picture

Nice unit but unfortunately, not sold in Canada since it does not meet CSA standards (shame...).

Michael Fremer's picture

?

rakalm's picture

Would still love to see you follow through on the Jasmine Phono Stage review you hinted at a bit back.  They have had 2 upgrades since the original review.  The new one can handle 2 turntables.  I know, a whole different realm but I believe or my ears lead me to believe the Jasmine is one of if not the best value out there.  Less than $600.  A great deal for those of us who suffer from budgetary contraints.  I looked at a Parasound in my price range with the onboard headphone amp and all and took your recommendation that it may have not been the best choice.  A borrowed Parasound (prior to receiving my Jasmine) from many years back (PPH-100) could not even compare to my Jasmine. I am guessing the Parasound PPH-100 was a great buy in it's day.  I am certainly not comparing the Parasound you reviewed except by name alone and the choices I had within my price range. 

patrick50's picture

Please excuse my naive question but is 100 ohms loading really considered as good as one needs for most MC cartridges? I do experience relatively subtle effects from loading but that catridge I currently use, a Clearaudio Concerto II, does seem to respond to a little lower (higher value) setting. I confess, I actually like it wide open at 47k too but 100 ohms just sounds a little dull. By the way, thanks for all you do for those of us who love LPs!

Ortofan's picture

The webpage for the Clearaudio Concerto II cartridge lists a recommended load resistance of 300 ohms.

Likewise for the technical data chart in the owner's manual.

However, the owner's manual goes on to say:

"Loading between 100 Ohms and 1 Kohms may be used with some solid state for best results.

We strongly recommend starting at 47 Kohm loading down until breaking in has been completed.

We achieved the best results with a loading of 200 ohms."

patrick50's picture

Thanks Ortofan -- I do have the manual but I was really asking a more general question about the utility of a 100ohm setting for most MCs. IF I had to use the 100ohm with the Concerto it would make music, but not as well as it does at other loadings. But maybe the Clearaudios are the outliers to the general rule?

Ortofan's picture

I've been using Ortofons for decades and the load for most of their MC cartridges is specified simply as >10 ohms.  Exceptions include some of the Kontrapunkt and Cadenza models, where the load is spec'd at 50-500 ohms.  Audio-Technica generally specifies a 100 ohm load.  However, I use a Tamura transformer as the step-up device, so the load for the cartridge ends up being whatever impedance gets reflected back to the input from the phono amplifier.

treyroscoe's picture

I was torn between the kW phono stage from Musical Fidelity and the JC-3, and went with the kW when I got a great deal on one. IIRC you had one of the kW phonos at some point. Can't find your review anywhere though. Can you speak to how they compare sonically?

Michael Fremer's picture

My kW review must have been in an Analog Corner that's yet to be published here. In all honesty too much time has passed since I wrote about it and had it in-house. Off the top of my head I'd bet the kW was more dynamic, had more bottom end grip and extension but was somewhat lean in the midrange where the JC-3 is more lush and full-sounding. 

Ortofan's picture

Some comments from MF about the kW as part of the Aesthetix Rhea review here:

http://www.stereophile.com/content/aesthetix-rhea-phono-preamplifier-michael-fremer-june-2005

readargos's picture

I’ve owned a lot of Musical Fidelity gear from the last decade: A3cr separates, A3.2cr separates, and A308cr separates. The limited edition Anniversary Tri-Vista kW power amp actually used some “trickle-up” technology originally developed for the A308 series. These components represent the Musical Fidelity house sound that won rave reviews on both sides of the pond, and what I like to think of as the “classic” Musical Fidelity sound.

I found a “new old stock” kW Phono from a dealer that I recently added to the A308 stack. I believe that, starting with the kW regular production line (*not* the Anniversary Tri-Vista gear), MuFi’s house sound went in different direction, from light, bright, open, transparent, fast, and airy; to a little darker and smoother with bigger (but not overdamped) bass and more physicality/palpability. The kW phono has depth charge bass, but lacks some of the high frequency filigree of MuFi’s earlier circuit designs. Both flavors of the MuFi sound, however, are superbly detailed and dynamic, and neither are harmonically lean (for solid state).

With the caveat that I have not heard the Tri-Vista kW Anniversary gear, or other examples of the kW regular production line, I believe Mr. Fremer’s description of the Tri-Vista kW conveys the gestalt of the A308 sound, while his description of the kW Hybrid preamp and kW750 power amp conveys the gestalt of the kW phono sound. I mention this because those reviews of Mr. Fremer’s are available on Stereophile’s website, while, as yet, the kW phono review has not been published online. Personally, I think the A308 gear is closer to a strict, uncolored neutrality, that is highly responsive to changes in cables to allow tailoring of the sound to suit listener preference. The kW sound starts out a little more tailored. The kW is not as dark as BAT solid state or some of the older Krell, but it’s not as explicitly open as Musical Fidelity’s earlier gear.

Make no mistake, the kW phono is a big step up from the good-quality internal phonostage of the A308 preamp (which handily showcases the superiority of even a modest vinyl rig over CD), but the sound is also a study in contrasts. If you’ve tuned a system around the A3, A3.2 or A308 gear, adding the kW may require tuning in somewhat the opposite direction. Those who are fans of the classic Musical Fidelity sound might consider loading the cartridge less on the kW to recover some of the brightness.

treyroscoe's picture

Many thanks for that impression. The dynamics and bass are two of my favorite aspects to the kW. Look forward to that review being posted at some point in the future. A great phono stage, but would love to see how it compared to others that you had around when you reviewed it.

Am I correct thinking that you will be at AXPONA this weekend? If so, I hope to meet you there!

Johnny2Bad's picture

" ...
Nice unit but unfortunately, not sold in Canada since it does not meet CSA standards (shame...).
..."
Michael Fremer added: " ... You Can't Just Sneak One In? ..."

You could, but it requires jumping through a few hoops. Parasound dealers are prohibited from shipping to Canada. You would either have to physically drive across the border, have a sympathetic friend who lives in the US (for a shipping address), or use a Customs Broker with a US warehouse. Mine does, but most do not.

I do find it strange that Parasound chooses not to have the unit tested to CSA standards, since Underwriter's Laboratory will test to CSA and US standards at the same time (as will CSA). Must be a decision to limit costs vs a small market.

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