XLR sound worse than RCA on Mcintosh preamp c2700

Just got Bartok and Mcintosh premap c2700, first tested sound quality by connecting with a very basic RCA cable, sound not bad at all. Then switched to Nordost Frey 2 XLR cable and expected much better sound, but to my surprise it sounded narrow and thin. How could XLR sound worse than RCA connection? Later I learned that Mcintosh c2700 is not fully balanced, so although it had XLR inputs, the connection between Bartok and C2700 is not balanced? What’s the best connection for Bartok and c2700? Thank you!

my RCA and XLR connections play differently, there are no winners. Choose which connection you like best in your system.
Bartok has both good outputs.

I though XLR suppose sound better than RCA.

Are you sure your XLR cables are new/ not modified/ not broken? Usually when a XLR connection sounds narrow and thin there is a problem with the cable. Bartók and C2700 have the same PIN orientation, so if all 3 leads are correctly soldered, this problem should not occur.

Page 11 of the Bartók manual:

I tested two pairs of brand new Nordost Frey 2 XLR cable but all sounded narrow and thin, don’t know whether they were broken or not. On page 11 Bartok manual it suggest to connect Pin 3 and Pin 1, how am I gonna do that?

Please do not do that! That is only necessary when the source is unbalanced (or vice versa, connecting one end unbalanced to other end balanced). For balanced out to balanced in (the C2700 is properly operating in balanced mode) you need standard XLR cables with standard PIN orientation:

C2700:
c2700

Bartók:
bartok-xlr-pins

So, PIN 1 Ground | PIN 2 + | PIN 3 -

As I said before, Bartók and C2700 are wired identically, so there should be no problem. Only the cables might be problematic.

What is the voltage out setting of your Bartók? 0.2 - 0.6 - 2 - 6V? And is your volume level set to 0.0dB, as should be in case you are using a preamp?

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Line level on Bartok was set to 2V and 0.0dB. I was confirmed by McIntosh that C2700 was not fully balanced. Does it mean that Just because there is an XLR input on c2700, but not necessary meant that there is a balanced circuitry on C2700, so the connection between Bartok and C2700 is not balanced. You suggest that I should not connect Pin 3 and Pin 1 as indicated on Bartok page 11, and currently connecting Bartok and C2700 with XLR not sounding right, should I just go back to RCA connection?

I would try different XLR cables first. Connecting both over XLR should work really fine. Can your audio dealer be of help?

Will try new cables. Thank you so much!

That is unfortunately ambiguous as the phrase " fully balanced" is colloquially used in two ways in the audio world.

The first is to describe a connection between two components where the signal is made into pairs which are inverted with respect to each other. Noise may be picked up equally by each wire of the pair but as they have inverted polarity with regard to each other when combined the noise cancels out.

However the way I think MacIntosh are using the phrase is to describe a component where the entire circuitry is duplicated in differential mode. That seems not to be the case here. However that does not indicate that the XLR inputs ( or outputs) are not fully balanced. There is “fully” balanced circuitry on the C2700 in regard to the XLR connections the but not throughout. That is to say that you do not have a balanced output from Bartok feeding a single ended input at the McIntosh end which just happens to use XLR connectors. It is properly balanced.

So please follow Erno’s advice.

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There are, however, other amplifiers (like Viva Egoista 845) which do use XLR input connector, but are ignoring pin 3 altogether, hence using XLRs just as a convenience plug, using it single ended.

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Balanced, differential, transformer balanced?

If you like to get an idea about what this all means, maybe you like to read the following article. It is about the famous Neumann microphones, but is equally applicable to other audio gear.

McIntosh gear is transformer balanced, solid state gear, if balanced, is/ should be differential, and preferrably dual mono/ channel separated.

To add:

Balanced signaling is two conductors (with an optional shield) that have equal impedance to ground.

Differential signaling is two conductors (with an optional shield) transmitting the same signal at opposite polarity.

For further reading (in case you like to be an expert, or just understand the gear you own):

https://www.hairballaudio.com/blog/resources/diy-resources/balanced-and-differential

and:

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I have found that Mcintosh stuff sounds thin and not dynamic in any way. Maybe the xlr is reflecting that better, and not colouring it. I have used that xlr and find it to be better than a bog standard rca

Hello,

(Just my personal experience here : Glitches and huge distorsion with RCA outputs on my Bartok ).

I also have a McIntosh pre-amp, a C70.
If not the same, it has a very similar analog part as the C2700 for what concerns the tube section (so not fully balanced either).

I actually had a quite similar issue as you with my Bartok.
Sound through XLR was very thin, with a noticeable lack of bass.
And, although the sound quality was much better with unbalanced RCAs, I ended up having glitches and distorsion coming out of the Bartok at start-up from time to time with the RCAs (could be hit once every four or five full power off/on).

Long story short, my Bartok was faulty.
It went back to dCS facilities where it got fixed earlier this year.
No more issue since it has been returned back to me: the XLR connection sounds now way better than the RCA when connected to the C70, “full of meat” while being quite detailed (I currently use the max 6V output setting on the Bartok, as the C70 can take up to 10V on its XLR entries).

Hope this can help,

Erwan.

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You are not alone. We have similar setup, but my preamp is the older version C2500. I got Bartok (upgrade from Chord Qutest DAC) in March this year. Similar to your expectation, I was excited that I finally have a DAC that has balanced output so that I can finally use the balanced input on my C2500. I initially borrowed a pair of XLR cables from the dealer while I was waiting for a new pair that I ordered somewhere else. However, the XLR connection disappointed me immediately, when compared to RAC connection (similar level of the cable). I would not describe it as thin or narrow, as the sound from balanced connection is still warm and comfortable, but it is about 10% lower in volume (I do not know how to translate McIntosh’s 10% volume to dB, but you know what I mean) and less dynamic/impactful (after I adjusted it to similar volume level). Initially i thought it could be the problem of the balanced cables that dealer lent me, but later when I received my brand new balanced cable, i heard the same, so I was able to rule out any potential cable issues. I then went through the exact same path as you did to find answer, and learned from McIntosh that C2500 is not fully balanced, and therefore I drew similar conclusion as you did. It was hard for me to digest why balanced connection sound worse than RCA. I struggled for a while and ended up letting it go. Since balanced connection did not sound bad, and its less impactful sound signature is actually good for longer listening, plus my belief that balanced connection should have better signal to noise ratio, I settled with balanced connection. Not ideal and not perfect, but I could not figure out why or any solutions.

My previous post regarding the issue, if you are interested to read:

Hello,

Regarding the difference of level between balanced and unbalanced, the output voltage setting of the Bartok is the same and applies to both.

On the McIntosh preamp side, things are different. The max voltage for balanced inputs is 10V (C70, C2700, …) whereas the max voltage for unbalanced inputs is 5V.

So if you set the Bartok line level to 2V, on the preamp side the max level will only represent 2/10 of the preamp capability for the balanced inputs, whereas it will be 4/10 (2/5) for the unbalanced inputs.

Hence the balanced volume being lower than the unbalanced.

Note that if you set the Bartok output level to 6v, you may be out of the max range for the preamp unbalanced input.
There’s no real risk for you to damage your preamp, but you will get some distorsion.

Hope this can help,

Erwan.

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For maximum volume on a (pre)amp you have to look at its input sensitivity, not maximum input level.

Input sensitivity is the maximum voltage strength of an input signal that an amplifier can handle and still produce unclipped full output.

The Mcintosh preamp C2700: Sensitivity High Level (Balanced / Unbalanced) : 900mV / 450mV

So, using RCA out on Bartók to RCA in on the C2700, you only need half the voltage to reach maximum output, than with XLR. At the same volume out level, the RCA will sooner sound more loud, which is not to be confused with ‘better’.

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Thanks @Ermos,
I was clearly missing/unaware-of that sensitivity aspect.
This clearly adds to my understanding.
Regards,
Erwan

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To McIntosh preamp owners with similar max/sensitivity specs as described above, if your gear provides an adjustable gain setting specific to each input (called trim on Mc if I recall well), you should be able to do direct Bartok balanced/unbalanced comparison by:

  • setting the Bartok line level to 2V
  • define a +6dB gain between your Balanced and Unbalanced preamp inputs (I’d set balanced +3dB, unbalanced -3dB).

This should allow to switch from Bartok balanced to unbalanced using the pre input selector and to get the same sound level at the loudspeakers.
Hope this can help,
Erwan

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