Having 2 volume controls that both work is a messy solution, would be better to be able to disengage the DCS volume to protect the system. Very confusing if you come to use the equipment and you aren’t the main user.
Adding a preamp makes a very elegant solution a little clunky from an experiential point of view.
John Atkinson seems to be a fan of preamps: https://www.stereophile.com/content/pass-laboratories-xp-32-line-preamplifier
But doesn’t use one it seems. 
Thanks for the link. I remember reading that. Insert what @James wrote before about the addition of an analog preamp after the DAC here.
Today i have some hearing fatigue i can only listen to Bartok connected directly to power amplifiers as it is the most natural and relaxed sound, so it is great to have a choice and DAC able to be a preamplifier
It is a fun to watch the evolution of my attitude towards preamplifier use with Bartok. I bought Bartok brand new. First 120h of burn-in was painful. Next 100h hours was ok, but still a bit grey , sometimes closed sound, sometimes aggresive and now after a month i see my tube preamp will stay only for riaa and for digital sources hard to imagine using anything between Bartok and power monoblock amplifiers. Now i think, that it would be nice to have riaa board inside Bartok to have a complete package. 
Hey DSC, why not have Bartok RIAA? Phono inputs besides digital?
Maciej, dCS have already tried marketing a DAC with Phono inputs and RIAA eq. It was part of the first generation of products and was called the Grieg. It was not a success and was quickly withdrawn.
The main problem for committed vinyl enthusiasts (include me) is that in order to function such a product has to digitise the analogue input ( using an ADC) which for many defeats the whole point of a owning a fine turntable and phonostage. It’s like asking a racing yachtsman why he doesn’t get rid of the sail and install an outboard motor 
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Thanks, who said it has to converted to digital?
I’m talking about pure analog phono riaa connected via relay between digital to analog conversion and analog output stage. It can be problematic if volume control is in digital domain:(
Which is where it is. That “d” in dCS has meaning.
One point to clarify - Grieg never got beyond the prototype stage and so was not put into production.
Hello, dCS community. I just placed a deposit for a Bartok w/ headphone amp and this is my first post! The discussion here is helpful but I have a couple of specific questions:
Sensitivity (into 8Ω)
High: 1.00V 100W
High: 1.41V 200W
Low: 2.00V 100w
Low: 2.82V 200W
Hi, and welcome to the community.
To answer your questions:
@Ermos Thanks for your reply. I’m new to all of this! For 1, just to confirm: if voltages are given per leg, does that mean the dCS quoted 2v balanced setting for example is equal to 4v total? In other words 2v carried on the positive leg and 2v carried on the negative leg of the balanced cable for a total of 4v? most standard outputs i’ve seen quoted are 2v single ended and 4v balanced.
Actually I found the answer I was looking for in the Stereophile review. I should have looked their first!
"With the Bartók’s volume control set to its maximum, a 1kHz digital signal at 0dBFS resulted in a balanced output level of 6.03V into 100k ohms with the output level set to “6V,” 2.04V with it set to “2V,” and 603mV with it set to “0.6V.” The maximum levels from the unbalanced outputs were all very slightly lower and the maximum level from the headphone output was 6.82V. "
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The reason for this is the way that balanced differential circuits work. The signal is split into two polarities which are inverted in respect of each other; + and -. When they are combined at the receiving end to reduce noise that has been picked up the two outputs are summed. Most manufacturers provide the single ended output by using only one half of the existing balanced circuit. Hence the single ended output is exactly half the voltage of the balanced one. 2V is commonly found as it was (is) the specified output voltage for CD players that meet the redbook standard ( ISO 13490).
dCS do not do this and actually build separate output circuits of different design for single ended and balanced. Hence they can make it so that both provide the same output voltage ( or as close as is possible).
Note that Stereophile measure the voltages using a signal of 0dBfs. Even if you set Bartok output as 0dBfs the music signal of well mastered recordings will be a few dB below this to provide some headroom so as not to drive everything into distortion. That means that although you can play with the numbers so that output voltage = input sensitivity this will not be consistent in real life. Another reason to follow Ermos’ advice to set the line output voltage so that the volume control is in a comfortable position . Further as Bartok’s volume control is digital and as digital volume controls work by reducing bit depth (i.e. resolution), when using it directly into a power amp you do not want to have to have the average position of the control set too low in order to produce a comfortable listening level . So in most home set ups where direct connection is used this may mean that it is better to set the line voltage level lower than at the maximum available.
No, 2V out is 2V out, not 4V total. The + and - are both 2V, in opposite phase.
@PAR and @Ermos thanks very much for clearly explaining how the voltage works.
I will start by running the Bartok into my pre amp (Bryston BP17(3)). According to Bryston the unit was designed around the standard 2V CD input you mentioned above.
As some point I’ll experiment going direct into the Amp. 2V will likely be the correct setting but experiment as you suggest to get the volume range on the Barktok between -30 and -10 as the FAQ suggests. My Bartok is on the way but it will be a few weeks yet…
Thanks again for your help!
I found in the data sheet of Bartok that the recommended input impedance is 10k-100kΩ
1 x pair balanced outputs on 2 x XLR connectors. Output levels: 0.2V, 0.6V, 2V, 6V rms for a full-scale input, set in the menu. Output impedance: 3Ω Maximum load: 600Ω (10k-100kΩ is recommended)
Next, I look at the input impedance of my ATC SCA2 preamp and see that for a balanced input it is only 2k7 per leg.
At the RCA input, everything is pretty standard.
What does the recommended 10k-100kΩ mean and how can this affect the sound in the case of working with a preamp where the input impedance is 2k7?
The term “maximum load” here is a bit confusing. The load is actually higher with a lower input impedance value. I’m not sure what 2k7 means, but assuming it’s something like 2000 ohms you should be fine, since it’s a lower load than the 600 ohm maximum. It’s not quite in the recommended range but I expect it won’t be a problem.
No problems. Your Bartok’s balanced output is absolutely fine with your ATC SCA2 preamp.
This is all about power transfer and the usual rule of thumb is that the receiving equipment’s input impedance should be at least 10 times the sending equipment’s output impedance for the most efficient power transfer . As 3 ohms output is 900 times less than the input impedance ( 2,700 ohms) it is completely suitable.
The dCS spec. basically just quotes the most commonly found minimum or maximum input impedance numbers for pre or power amps. In other words it will work with just about anything except for unusual outliers.
Remember that I also own an SCA2 !
Its just a bit of engineer’s jargon and uses K instead of thousand or 000. so 2K7 is 2 thousand 700. 8,600 would be 8K6 etc.