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Parasound JC2 Preamplifier Review

waynel

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Those specs translate into a SINAD of 96 dB.
Thanks , and I assume that with digital input the specs translate to 100dB SINAD since .001% is 100dB and the SNR is 113dB. Do you agree?
thanks
wayne
 

Ajax

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I love to have the combination of state-of-the-art DAC and pre-amp. Usually though the former is throw-away.

Firstly, thanks for the work you do, you are providing an invaluable service and helping a lot of people make rational decsions. I'm not sure if it pays the bills or not but I am very appreciative to have a place where I can find impartial information, and rational debate, and have made a small contribution.

I have the Benchmark DAC2, which I use as a preamp as it has both analogue and digital inputs together with volume control. Sounds fantastic to my ears (you will recall that you reviewed the DAC3 and the AHB2 power amp). To those interested you can purchase the DAC2 2nd hand for around $US900. It was the first in the Benchmark range to incorporated asynchronous technology.

I also have a Benchmark DAC1 HDR, which I purchased new in 2010 and it has not missed a beat for over ten years. Awesome company who provide excellent products, quality and service and IMO the leaders in the US in the field of digital audio technology.

PS - I have no allegiance as I in live in Australia.
 

b1daly

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ABX testing feeds into the biased theory that the sound signatures of front end components is far past negligible in all but the most extreme of cases with those with the most acute abilities.... wait a minute...
Hah hah, good point!
 

anmpr1

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With increasing use of room eq, the channel balance (even between L and R) is becoming a non-issue as it is the first step done in that process. This channel gain is a hold-over from the older generation 2 channel analog only pre-dating any DSP use.
The thing is, though, with certain recordings the balance is off from the get go. All the room EQ in the world will not change that since it's coming from the source. Especially an analog source, such as a record player, where phono cartridge channel imbalance may likely manifest. Play a mono record and you'll frequently find that the image is not in the center, between the two loudspeakers. And with tape, with monophonic recordings, you'd often find different programs on different tracks.

Of course, if you never listen to monophonic recordings and don't use a record player/tape it's not much of an issue, probably. With a digital source (PC) everything can be done via software if you need it. But then why would even need a dedicated preamp, if that's the case?
 

anmpr1

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I see no opportunity for Parasound's market share to grow, but their "old-fashioned legacy audio" products will probably survive for a while. There have been some comparisons with Schiit Audio gear in this thread, and I believe that as far as boutique audio products go, Schiit, with it's modern, compact amplifiers and preamps that complement their digital products, will thrive and grow as Parasound fades into obscurity and finally drops off the radar.

Parasound, PS Audio (their Bascom King amplifier), Pass, and others like them can only survive due to hype and the 'names' associated with the gear. But as you say, I would guess that as the consumers who became audiofools during that era, once they leave the hobby, the new kids on the block will by necessity gravitate to kit like Schiit gear. For them that company's name isn't off putting, and the stuff has a 'cute 'n cuddly' look/feel to it. Plus it is pretty cheap in the scheme of things. Very few people, mostly older folks, can afford the price of a BHK or a John Curl amplifier. And engineering oriented audio fans will gravitate to companies like Benchmark, who offer unbelievable value at a realistic price.

The full of Schiit guys have done a pretty good job straddling the tweako/decent engineering/value market. Plus, the stuff is made in the US. People generally want to buy locally. The company is sort of like the old Dynaco (sans DIY)--great price/performance ratio (at least when they decide to do the engineering thing correctly--something they've demonstrated they can do if they want to--thank to ASR for that probably). For their part, Parasound is living off the 'Mark Levinson JC-2' vibe. How is that going to work out for them in the long run? Ironically, even Mark Levinson (both the man and the Harman company) moved away from that scene long ago. LOL
 

ta240

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This.

One can disagree with the philosophy of design but I think there is a tendency to confuse bad/sloppy engineering in failing to meet chosen goals (transparency or sound signature) with competent engineering to meet a goal whether you agree with that goal or not.

Correct. If they set out to have the amplifier perform the way it is performing then they engineered it perfectly.

Does using the word 'perfectly' mean that it is the audiosciencereview definition of a perfect amplifier? No. Is it good for their customers to know what they are getting. Yes. Are people still going to buy it and like it? Most likely. Is that wrong? Not to me; people should get what they enjoy.
 

Vasr

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The thing is, though, with certain recordings the balance is off from the get go. All the room EQ in the world will not change that since it's coming from the source. Especially an analog source, such as a record player, where phono cartridge channel imbalance may likely manifest.
I don't disagree with the above use case (however common/rare it might be). My point is that with room eq becoming ubiquitous dsp based channel balance as an available function (that you can manually tweak) is a given. For your use case, it would be far more usable to provide that as a button on your remote than even knobs on the device. Whether it is better or worse aurally implemented underneath as an analog circuit is more of a religious debate.
Of course, if you never listen to monophonic recordings and don't use a record player/tape it's not much of an issue, probably. With a digital source (PC) everything can be done via software if you need it.
Not everything but I completely agree.
https://www.audiosciencereview.com/...ring-a-pc-as-a-8-ch-pre-pro-experiment.14785/:)
But...
But then why would even need a dedicated preamp, if that's the case?
If you look at it beyond the legacy-derived name of pre-amp for its functionality, that is THE ONE logical unit in the audio stack to provide the greatest invention in audio:
remote.jpg


It is the one that provides the main interface to control sitting between sources and output. No amount of PC hacking can come close to it.
 

gpauk

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There's some comment over on DIYA that it measures poorly as it's tested at 4V which is out of the design spec. (in part, a way to try and blame ASR!!)
What does the product spec actually say?
 

pma

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There's some comment over on DIYA that it measures poorly as it's tested at 4V which is out of the design spec. (in part, a way to try and blame ASR!!)
What does the product spec actually say?

Much more. Up to 8V.

https://parasound.com/jc2.php

And do not forget it was balanced. 4V balanced equals 2V unbalanced. Perfectly standard Vout for a line stage.
I am especially disappointed with distortion rise with frequency. This is poor.
 

gpauk

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Thanks - and yes - comes with an ideology that says feedback is bad....
 

Xulonn

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If you look at it beyond the legacy-derived name of pre-amp for its functionality

I don't know what you consider to be a "legacy-derived name", but I have always considered the name "preamplifier" to simply be a device between source and amplifier, e.g., "before" the amplifier. A preamplifier is not necessarily an amplifiation device itself, and the terms "active" vs "passive" have been used as long as I can remember to indicate whether a preamp includes a gain stage. McIntosh has used the terms "control center" and preamplifier interchangably for some of their units, and the primary function of many preamplifiers is to serve as a control center.

The definition of the suffix "pre-", based on its Latin root, is "before." Preamps range from single-function simplicity to complex monsters, especially AV preamps. They can provide any or all of the following "before" a line-level audio signal is passed on to a power amplifier:
  • additional low-level amplification
  • RIAA and other phono equilization
  • buffering
  • impedance matching
  • attenuation (volume control)
  • tone controls
  • balance control
  • mode selection
  • source and function switching
  • ADC/DAC and DSP (Recent additions to the list)
  • etc.
 
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bigguyca

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Thanks , and I assume that with digital input the specs translate to 100dB SINAD since .001% is 100dB and the SNR is 113dB. Do you agree?
thanks
wayne


The Anthem noise specs appear to be A-weighted. Per memory, ASR uses unweighted noise measurements. How are you converting from A to unweighted or am I missing something?


Switching to the JC2:

It appears the best way to get good specifications for the JC2 would be to use a low noise, low distortion, low voltage, low impedance input from the AP gear, with A-weighted measurements, and set the JC2 for minimum attenuation on the volume control. This would seem to minimize noise from the POT.

For example, .5V input, 12dB gain for 2V output. Experiment to find the sweet spot.

Also note, it isn't clear what settings were used in the Stereophile measurements.
 
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pma

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It should have been designed the way you would not need to find the "sweet spot". And it is possible to make so. Everything else are just excuses.
JC2 volume control is made this way, which is far from optimum. High impedance pot feeding nonlinear JFET input capacitances.
img372-1.jpg


jc2_inside3-1.jpg
 

Silly Valley

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With a few here piling on and proclaiming Parasound's demise based on the disappointing review of a rather old product, I will put forth a few thoughts:

1. While there will always be an unhappy few, Parasound seems to get good marks on customer service. They have had a few products with issues like the P5's volume control but in the grand scheme their track record suggests pretty reliable gear.

2. They have had good success with many studios using their goods. They have been able to prosper in professional, custom install and home applications. So apparently not everything they build is perceived as poorly as was the JC2 reviewed here.

3. To those painting them as a dying dinosaur, maybe not. It seems you may not be up to date on their offerings. If you take a look their product line, you will find class D amps in several products. They also have products with a nice combination of features such as HT bypass, analog bass management, and other useful features which are lacking in many other's lines. I would not call this stuck in the past.

I have no association with Parasound other than owning a single one of their amps which has been more than satisfactory for the intended application. I really thought about passing on this post all together but a few of the statements made here just don't align with reality.
No doubt, much of the Halo gear does not bench test with bleeding edge performance. But enough of it is obviously deemed "good enough" for many. While they still embrace some old school designs, their product line is evolving., maybe not a light speed but hardly standing still.
 

timing3435

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When I drop off my Yamaha MX-1 with @amirm, I'm happy to bring along my Parasound P5 with it. Currently, pulled both out of my system to try out a Soncoz SGD1 fed straight into an Icepower 1200AS2 based amp.

The P5 is an odd bird in their line-up. It's very "not audiophile" if you take a look inside.
I have a Yamaha MX-1 also. Is it going to get measured ? Thanks, JAJ
 

ChrisMag2099

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"Notice how the gain controls have their own distortion characteristics, performing worse when lower gain than higher(!). This is some odd behavior. "

I asked John Curl about this on a Zoom call tonight. The gain controls on the front of the JC2 don't increase gain. They are a trim. His recommendation was to leave them in the +10 position if possible.

Per the manual:

Adjust your power amplifier gain controls (if it has them) so that your JC 2 master volume knob’s indicator is between 11 o’clock and 1 o’clock for your most typical listening level. This is its “sweet spot” where the control’s left/right channel tracking is closest and its distortion is lowest.

In most cases you will simply leave the Left and Right knobs fully clockwise where the potentiometer wipers make direct contacts and are out of the circuit.

In the case of my JC2BP/JC5/Sopra 2 combo, setting the front L/R gain settings to full on the front of the preamp, the input gains on the amp to 12 o’clock results in the optimal listening level to be within the 11 o’clock and 1 o’clock range per the recommendation.
 
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