Hi Kabes, welcome to the forum which I hope you will enjoy and find useful.
The implication of your question is that there may be a correct or universally acceptable setting. This is not the case and where dCS offer a choice of setting ( output voltage, filters, dither or not for those with wordclocks) it is because the selection that is suitable for different listeners varies.
The purpose of a choice of these output voltages is to enable the user to set the volume control within a reasonable range. This will depend upon choice of repertoire, sensitivity of amplification and speakers, size of room, how loud you like to listen and personal taste. However when connecting Bartok to an amplifier directly ( not using a volume control on a preamp) then the voltage chosen with average level listening should have the Bartok volume control rotated to give a setting for comfortable listening between 0.0dBfs and -30dBs. I practice would expect the setting to be something like between -5dBfs and -15dBfs. Of course if you use a preamp with its own volume control then you choose a voltage output setting that allows a comfortable position with the preamp volume control control and using Bartok with full output at the chosen voltage setting. This is 0.0dBfs.
Obviously if the voltage setting is too high then the listening level may be too loud even at the lowest settings of the volume control or too quiet even using 0.0 dBfs
I would start by using a setting of 2V. The reason is that this is the specified voltage for the output of CD players processing a signal of 0.0dBfs ( see the redbook). This has become a de facto standard for many uses. It therefore means that most input sensitivities of preamps etc. have been designed with this voltage in mind.
I see. Thank you for your thorough explanation. I just received my Apex Bartok unit yesterday and will play around with the settings.
What prompted my question originally though, I noticed a decrease in volumes between inputs. My âbalancedâ dCS input running via XLR out from my dCS was much lower versus my âopticalâ input that I was using a Bluesound Node streamer into my preamplifier DAC. The Bluesound optical connection running into my preamplifierâs DAC and out to my amplifier was much louder for some reason.
Thatâs what led me to start to figure out why and that maybe it was a voltage difference. Funny enough, the Bluesound Node streamer is at 2v but for some reason is playing louder. Iâm not sure if thatâs just because itâs a digital input and (does digital inherently play louder?)
I donât have a problem using 6v or 2v based on my preference. What I am trying to solve for is why the dCS balanced input on my preamp sounds so much lower than my digital input that is equally at 2v.
[quote=âKabes, post:22, topic:1824â]
I donât have a problem using 6v or 2v based on my preference. What I am trying to solve for is why the dCS balanced input on my preamp sounds so much lower than my digital input that is equally at 2v.
[/quote]I
am trying to understand what you mean and apologise in advance if I have this wrong. What you seem to be saying is that setting the dCS voltage at 2V sounds lower than your Bluesound Node streamer. Is that right? if so what is the output voltage specified when processing data recorded at 0.0dBfs using the optical input? I am assuming that the data is the same for both tests.
Would you kindly tell me what model of Bluesound Node you have so I can check the spec.
Yes, thanks, you got it and thank you for being so responsive. I have my Bluesound streamer connected optically and via unbalanced and both sound louder than the dCS. This would be using my unbalanced and optical inputs on my preamp playing the exact same track and switching between the two. The Bluesound Node is set to âFixed volume.â
My Bartok is connected to the balanced input on my preamp at 2V. When I switch to 6V volts it does play louder the the Bluesound. I also checked to ensure the gain levels were at 0 for all 3 inputs on my preamp.
Different output designs may provide different output voltages for nominally the same input. In this case the output voltages cannot be compared as the specification for Bluesound Node gives no figures. All it says is that there is a choice of fixed output. So " fixed volume " presumably provides a higher voltage than the 2V output selected for the Bartok which is why it is louder. We have no way of knowing from the specification. The optical input connection has no voltage per se.
I really appreciate you chiming in to help. Frustrating to think that my $600 Bluesound is playing louder than my dCS. I did confirm that the Node at fixed volume outputs 2V. Iâve also tried swapping out XLR cables to a different brand and have gotten the same result. At 2V in the dCS I am forced to play the volume 10% higher to get to the same volume of the Bluesound Node.
Single ended inputs may have higher sensitivity than balanced inputs on your preamp. Try single ended output from your Bartok with 2V output setting to see how it compares (and/or look at your pre/amp specifications). Hope this helps!
Subjective assessments of loudness are not a reliable guide to quality which is why such things never feature in specifications or test data. In fact a very good unit which allows the processing of the widest dynamic range may sound quieter than another which is limited and compresses dynamics. This is because in digital audio the maximum signal level is fixed ( i.e 0.0dBfs). This means that in order to encompass wide dynamics the average sound level has to be lower.
In any case this is does not matter in real life as if the resultant sound is too quiet then advance the volume control, too loud then retard the volume control. After all that is what it is for and what you paid for
Thanks, Pete. I just didnât expect such a stark difference in volume. With that, can you educate me on the volume and how dCS implements it? Is it similar to a fixed methodology like the Bluesound for preamps or something different when I set it to 0 dB? I see there is no fixed option in the Bartok. Thanks again for trying to help me through this. I also checked and my McIntosh C53 preamp supports 10V balanced if I wanted to bump it up to 6V on the Bartok.
Iâll try. A unit with a fixed output voltage provides maximum voltage when it processes a data stream representing the maximum recorded level of 0.0dBfs ( deciBel , full scale). In this case Bluesound only has an optical output so it is not really possible to compare output voltages from one unit against another. However the optical stream will provide that a data level representing 0.0dBfs should result in the processor producing its maximum level (for that input).
Where the output level is variable then if a maximum recorded level of 0.0dBfs is processed this will also provide the maximum output signal level . However being a variable output the voltage when processing a recorded signal is changeable. This maximum voltage in dCS processors is set by a combination of he volume control position and the selected line output voltage.
When playing a normal recording the maximum recorded level varies continuously as dynamic swings occur. The maximum level of 0.0dBfs with good recordings is rarely reached as a few decibels are left in hand to avoid accidentally exceeding the maximum level subsequent to which there is nothing left except distortion. Rock or pop records can go close to or exceed the limitations and you might want to read up on this by googling " Loudness wars".
I used to wrongly think that lowering digital volume reduced resolution with dCS units but Phil corrected me on this some months ago ( sorry I canât find a link).
I am not sure what else I can tell you except that the figures given by dCS are pretty accurate so if they say the maximum output voltage set is 6v, 2V, 0.6v etc it will be that plus or minus a very small percentage. Similarly if the digital volume control is in use and it attenuates by , say, 20 dBfs that is exactly what it is doing.
According to the McIntosh C53 specs the high level input sensitivities are 900mV for the balanced inputs and 450 mV for the unbalanced (single ended) inputs. And the specified gain of the preamp from the high level inputs is 15 dB. This means the unbalanced inputs only require half the voltage to provide the same gain as the balanced inputs. Seems like a simple test to try. You should be able to run both from the Bartok to see a direct comparison by A/B switching the C53 input selection.
Kabes, you might also want to double-check the âDigital Gainâ setting on your C53âs Digital inputs - Refer to page 18 on your C53 Ownerâs Manual and ensure that your digital gain setting for the optical input that your Bluesound is connected to is the default 0dB, not anything else.
It worked! Canât believe it. I donât understand though. I always thought balanced was better than single ended. Everyone preaches that. Why am I getting more volume from single ended vs balanced?
Canât thank you enough for chiming in. I was stressed out, LOL!
Thanks so muchâŚ. Steveâs single ended suggestion worked. The volume is now the same at 2V. The balanced input was for some reason lower than my single ended input. I really donât understand why because I always thought balanced was supposed to be better.
You should still be able to get your desired output level from the balanced output by a) selecting the 6V output level, and b) attenuating the output level to about -3.5 dB (this should be doable in the âUnit Setting > Output Levelâ settings menu from Mosaic).
You might want to disconnect the unbalanced cables before doing so since the C53 is only rated for 5V over the unbalanced inputs. Better safe than sorry.
The loudness or sensitivity of one input compared to another does not make one âbetterâ or worse. It simply means that the the designer has decided that the given sensitivity for each input is the most suitable. As @SJF pointed out:
Why? The designer may no doubt have taken account of the fact that many sources ( CD players, streamers etc.) provide outputs which provide twice the voltage of the single ended outputs. The reason is that a balanced connection uses two signals for each channel each of which is out of phase with the other. the result is that interference like EMI or RF is picked up by both . However at an input only the difference between the two is amplified and the common , out of phase, signals cancel each other out also cancelling out the interference. However the voltages of each phase are added. So the designer may have chosen that the balanced input sensitivity should be lower than that of single ended to make a correction for equipment that doubles the output voltage for balanced.
dCS equipment , however, has a more sophisticated ( and expensive) way of deriving the single ended or balanced outputs. It uses completely separate output circuits for single ended or balanced instead of using one half of the balanced circuit to provide single ended. This means that instead of the balanced circuit having twice the output of single ended both can be made the same. Therefore as the McIntosh may have a lower input sensitivity for balanced if this is the case it will not sound as loud as single ended. This isnât better or worse it is just the result of the amp input designer taking account of less well designed outputs.
If I still have your attention, I was curious to know if youâd be willing to share how you have your DAC connected or at least provide a recommendation to what you feel has been successful.
Based on my rig I have a few ways I could go:
A. Continue to use a short run single ended cable unbalanced at 2V. Based on the noise cancellation attributes of XLR I am not sure if I would lose anything here. My preamp and amp are both fully balanced I believe.
B. Use balanced XLR and increase to 6V (forgive me but I could not find the settings you were referring to in the Mosaic app to turn it down to 3.5) can you clarify a bit more?
C. My preamp actually has a +/- dB gain option per input. So I can actually use balanced at 2V and increase the gain on the balanced input. Iâm just not sure if it would be better sonically and safer to just have more voltage coming in from my DAC or increase the volume of the balanced input on my preamp.
I know these things can be quite subjective, but you donât know what you donât know, so I am just looking to gather knowledge from the experience of others.
Thanks! This is actually the first thing I checked. Managed to figure it out though between balanced and unbalanced and the sensitivity difference. Appreciate you trying to help.
Thanks, Pete. This is great information and I understand it in part. Based on the dCS output circuit design, wouldnât that negate the benefits of having a balanced cable if the voltages are the same between balanced and unbalanced?
Forgive me as Iâm sure I maybe thinking about this wrong. I always thought a balanced cable adds additional gain benefit but based on the dCS logic I guess itâs looked at differently.
Yes you are right n that. You are thinking about it wrong
Balanced connection fundamentally has nothing at all to do with additional gain or voltage. If these factors exist , and they may not, it is merely a side effect of the way that the balanced connection has been executed.
As I have tried to explain above the reason for balanced v. single ended is that the former has greater rejection of parasitic noise like EMI or RFI. ( interference). It does this by using Common Mode Rejection ( CMRR - the second R stands for ratio). How it does this in practice is as per my explanation:
[quote=âPAR, post:36, topic:1824â]
a balanced connection uses two signals for each channel each of which is out of phase with the other. the result is that interference like EMI or RF is picked up by both . However at an input only the difference between the two is amplified and the common , out of phase, signals cancel each other out also cancelling out the interference.
/quote]
To try to clarify; the interference is picked up equally by both conductors but these are out of phase in relation to each other. So when these same but inverse phase signals are added together only the different (i.e. out of phase) signals are amplified but the noise that has been picked up by both conductors being the same (not inverted in relation to each other) is rejected and not amplified
I apologise if I am not entirely clear but I have tried to be
