Analog Gear News

Parasound Introduces Improved Edition Halo JC3+ Phono Preamplifier

Michael Fremer  |  Dec 12, 2013

Parasound today introduced the John Curl designed JC3+ phono preamplifier, an improved version of the highly regarded JC3. The original JC3 proved problematic for cartridge loading fetishists in that it offered limited fixed moving coil loading of 100ohms or "wide open" 47kOhms chosen via via custom-made NKK selector switches with gold-on-silver contacts.

Legendary designer John Curl insisted on the fixed resistor arrangement to keep noise ultra- low. Potentiometers generally have higher self-noise and for most end-users 100 ohms is the correct or close to the correct loading.

However, some enthusiasts and reviewers complained 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.

While the designers were at it, they made other improvements to the new edition including narrowing the spectrum of Johnson/Nyquist 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. 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.

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 lilly, at the behest of the few, the finicky and the fanatic, the front panel's illuminated "P" logo can now be switched off.

The new JC3+ available in both silver and black finishes has a suggested list price of $2850 and will be available in late December.

COMMENTS
Trace's picture
Submitted by Trace on Thu, 2013-12-12 19:09

     something to covet.

Ortofan's picture
Submitted by Ortofan on Thu, 2013-12-12 19:13

Might you have meant to say low-ESR, or low-ESL, perhaps?

Michael Fremer's picture
Submitted by Michael Fremer on Fri, 2013-12-13 09:02

Press release said "ESD" so I dutifully repeated it but I wasn't sure what it meant either. I'll axe...

Michael Fremer's picture
Submitted by Michael Fremer on Fri, 2013-12-13 12:08

It was a typo in the press release that I dutifully copied. It's now corrected. Thanks...

Ortofan's picture
Submitted by Ortofan on Fri, 2013-12-13 22:07

Speaking of the press release and accompanying photos here: http://www.gspr.com/parasound/jc3+.html

Look at this photo: http://www.gspr.com/parasound/images/jc3+interior_300.jpg

Specifically (near the top of the photo) the odd bit of wiring and componentry to the right of the Takamisawa RY12W-K relay and in between the two small electrolytic capacitors.

Can you inquire if that is some unique Carl Thompson circuit board layout element or is it a special John Curl circuit design tweak?  Could this be the secret to how they achieved the "blacker" backgrounds? 

Samurai7595's picture
Submitted by Samurai7595 on Sat, 2013-12-14 05:17

I emailed Parasound and was told that their products are no longer being sold in Canada since they are not CSA approved.

marklind's picture
Submitted by marklind on Sat, 2013-12-14 18:24

I own the JC3. Was there any mention of an upgrade path to owners?

fabby2's picture
Submitted by fabby2 on Sun, 2014-04-20 07:19

If you compare picture given by Ortofa:

http://www.gspr.com/parasound/images/jc3+interior_300.jpg

And the official picture from Parasound:

http://parasound.com/img/halo/jc3+_black_interior_big.jpg

It seems that the area with the suspicious welding was erased :-)

fabby2's picture
Submitted by fabby2 on Mon, 2014-04-21 01:26

Please find the answer from Richard Schram:

Hi Fabrice,

Thank you for your message and for bringing the two photos on Michael's site to my attention.

Our products go through a number of stages during their development. 
One of the prototype samples had a minor fault in its turn on circuit but was otherwise suitable for testing everything else.
The correction of the fault on that set was done like a "patch" before the next sample with the board layout revised and subsequently also production units.
.

The JC 3+ photographs are of the earlier sample.  To mitigate the cost of our professional photographer we usually send batches of products for him to shoot during a one day session.
We sent the earlier sample because it was expedient.  We had forgotten about the rought spot on the board and sent out the PR release.  After we realized this we photoshopped that image.  I imagine the next time we send a batch of new products for phototgraphy we'll include a production JC 3+ with an actual production board. 

I'm sorry for a long answer to a simple question.e

If you don't mind posting it I would appreciate it.  I spend a lot of time answered emails personally (as you can see- it's 8pm on Sunday) and I'd be overwhelmed repsponding to blogs.

Thank you again for your message.

Kind regards,
Richard Schram
President
Parasound Products, Inc.

Michael Fremer's picture
Submitted by Michael Fremer on Tue, 2014-04-22 07:34

UR "fabby"

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