Parasound and dCS

Hello,

I’m new to this forum and i’ve got some interest with the Bartok on my system to replace an Auralic Aries G2 and a Totaldac d1-core.

My pream is a Parasound JC-2 ans my amp a Parasound JC5.

Does anyone try a dCS Bartok with a Parasound JC-2 ? If yes with which settings for output voltage ?
I’m plan to test it with 0.2V as output voltage to match the sensitivity to the JC2 :

Input Impedance
Unbalanced: 30k ohms
Balanced: 30k ohms per leg

Input Sensitivity
200 mV for 1 V output
Total Gain: 14 dB
Maximum Output: 8 V

https://parasound.com/jc2bp.php

Does it make sense ?

I’ve issue with my Totaldac output with 6V and the JC-2. With the volume of the DAC to 0 (full), and the preamp set to 0 (no sound), i can hear sound coming from the speakers … The sweet spot of my preamp is between 11 and 1 o’clock. But i can barely use more than 9’o clock (0 is 7 o’clock)
I’ve to set the DAC volume to -30dB to avoid this, but the sound quality is not great in this case.

Do you think that 0.2V i will be able to use the full SQ of the preamp and the Bartok too (with volume set to 0 with the Bartok) ?

Thank you !

In practice the input sensitivity figures for you preamp are of interest but will not reflect what is happening in reality playing real music.

That 0.2V output from the Bartok relates to the music source having a modulation level of 0dBfs. Real music files (or silver discs) normally have a maximum modulation below that as, unlike in analogue recording, you cannot push the maximum level and the recording engineer will try to ensure some safety headroom. Even the peak modulation of the recording may not reach 0dBfs. OK there are issues with some pop recordings from the “loudness wars” era but I will put those aside as being of reduced audiophile interest anyway.

So my advice is suck it and see. My expectation is you may prefer a setting of 2v in practice finding even 0.6V too low. Remember with that setting 2V will rarely if ever actually be reached. I am also perfectly sure that the designers of your preamp will have designed the line level nputs to expect devices to have an output of 2V for a recording modulation of 0dBfs as that is the official standard for CD players.

The thing is it is just so easy to change the output voltage on current dCS models so just choose what you feel happiest with.

Right now i’m using my DAC with volume set to -10dB. So 2V is already output from the DAC (if i’m correct of course and i reach the max :slightly_smiling_face: )). And sounds come from the speakers even with the preamp set to 0. Of course, less but it still exist. And i can not set the preamp between 11 or 1 o’clock too without having my ears bleeding :smiley:

I really would like to optimize the gain of my system and use all of the products at its full potential, but it can be complex sometimes :slight_smile:

Sorry to maybe ask so dumb questions ! (for the record, english is not my natural language :wink:)

If you are using a preamp set the DAC’s output to 0.0dB. You control volume from the preamp. From your description I guess that may mean that the volume control of your preamp may be comfortable set between , say, circa 9 o’clock and 12 o’clock. Fine IMO. I use a preamp and in my case with most music I like my volume control, at around 8 o’clock ( though settings on one pramp can have little relevance to another) . However as a classical music listener I do listen at a lower level than some audiophiles ( average circa 55dB).

I am a South London Cockney so some would say English is not my first language either :smile:

BTW, your English seems excellent.

Hello thank you for you answers and for my english, i’m trying to do my best !

I assume that your guidance is for the Bartok, regarding volume setting etc … ?

Let me explain my actual setup/situation maybe more clearly :slight_smile:

This is my preamp volume knob set to 0, so normally no sound.

As you can see, for « 0 » volume, it’s about 7 o’clock.

With my DAC (Totaldac, i do not have a Bartok yet to try because of the COVID-19 :frowning:), with 6V output, with the knob at 0 volume, i can hear lyrics of a song played at a distance of 3m of my loudspeakers. There are not too much sensitive, 90dB. My amp is a Parasound JC5, so gain matching is normally not an issue.
With this setup, i can barely go more than 8 o’clock …

For normal listening, i set the volume of the DAC to -10dB. If i’m correct, it reduce from 6V to 2V.
Even with this and the volume of the preamp set to 0, i can hear lyrics too, but at 1m-2m only.
With this setup i can go to 9 o’clock and a little more.

Set the DAC to -30dB and now, no sound is coming from my speakers when the preamp is set to 0 (7 o’clock). But eh digital volume control stat to show its limit and affect the sound too badly.
-30dB is 0.2V from a 6V signal … This is why i’m asking if this settings will match my system or not with the Bartok to try to use the maximum of the potential of each components.

Normally the optimal volume setting of the preamp is between 11 and 1’o clock …
Or maybe it’s not an issue. But having sound even with the preamp set to 0 sounds like a issue to me :frowning: Or maybe not …

Yes that sounds like a problem to me too as with a 2V input ( as I say that is standard) you should not be hearing anything if the volume control is set to maximum attenuation; 0. Are you by any chance using exceptionally sensitive speakers such as horns?

With a 0.2V max input into a normal line preamp I would expect the sound to be too quiet for normal listening ( subject to everything else being equal which it may not be , for example using horn loudspeakers).

BTW 6V input is rather high for a preamp.

My speakers are Sonus Faber Venere S with a 90dB sensitivity

That is a useful sensitivity but it is not what I would term a high sensitivity speaker.

There is a question too of what amplifier you use but I think that the real question is why the volume control is not attenuating a ( calculated by you ) 2V input signal to silence. I know that the JC2 produces very high gain ( 20dB) for single ended input coupled with using the balanced output but if that is not the case for you then the gain should be 14dB.

I would query the failure of your volume control to produce silence at 0dB setting and the difficulty you seem to have setting comfortable listening levels without using untypical settings with the Parasound. The “JC” in the product identification stands for John Curl, one of the all time great audio designers, so I doubt that there is a design fault. However the volume setting problems just strike me as there being something wrong with the preamp and I wonder if you have a faulty volume potentiometer?

Many of the Totaldac DACs output twice the voltage for the XLR outputs compared to RCA. How is the behaviour if you just connect it up single ended ( RCA throughout)?

This is what I read a little while ago with the use of 0.6V:

So as Pete mentioned, 2V should be right to use with a pre-amp, and 6V is usually required in direct to power amp.