Playing with RCA vs Balanced in my setup

[Sherwood]

On a related note I am planning to get one of these when they are back in stock and a second Raspberry Pi (3)

http://iqaudio.co.uk/audio/47-pi-dac-pro.html

This will allow me to bypass another component (my standalone DAC) and stream music directly to my monoblocks via XLR cables.

I am hopeful that this will further improve the sound of my system.

Geoff

[RothwellAudio]

Since one of the loaners i was going to receive was single ended only, in anticipation I switched the Amp to the 'Regular' single ended circuit, via jumper. I used a 1 meter IC directly between DAC and Amp. Volume control is digital using the 64bit in JRiver's player on my server. Then played to see if my 'baseline' sound had changed from the XLR setup. It had.

Is that a 1m RCA interconnect between DAC and power amp? Does the DAC have an RCA output as well as an XLR output? What is the DAC?
When you refer to "the XLR setup", is that the previous setup using a balanced pre-amp in the system?

The adapator is http://www.ebay.co.uk/itm/111803097651. Pin 3 is jumpered to Pin 1 and chassis.

There are different ways to create a balanced output but I think most won't take kindly to having pin 3 connected to pin one. Basically, the op-amp (or whatever it is) driving pin 3 is being short circuited, which is not a great idea. Pin 3 being left open circuit would be preferable.

[brucew268]

There are different ways to create a balanced output but I think most won't take kindly to having pin 3 connected to pin one. Basically, the op-amp (or whatever it is) driving pin 3 is being short circuited, which is not a great idea. Pin 3 being left open circuit would be preferable.

Are you saying that it could be dangerous to the DAC's opamp? My primary point in the OP and Post #8 was that it sounded better than just using the RCA out with the same cable.

Is that a 1m RCA interconnect between DAC and power amp? Does the DAC have an RCA output as well as an XLR output? What is the DAC?
When you refer to "the XLR setup", is that the previous setup using a balanced pre-amp in the system?

Yes, 1m RCA.
Yes, as I said, I tried both DAC outputs. Calyx 24/192 DAC.
Yes, well a preamp seemingly meant by Classe Audio to be the partner to the amp. It has both balanced and single ended inputs and outputs, though the jumper change is only on the amp, not the preamp.

[Dauntless]

I can make you one... Balanced in and out is I presume what you want?

Sounds like a good offer to me Balanced phono stages must be pretty rare.

[Arkless Electronics]

Most op amps are short circuit proof but it is not a good idea to short the output anyway. However, in most cases there will be a resistor after the op amps output which means it's usually ok in practice. Shorting pin 3 to 1 at the receiving end but leaving pin 3 open circuit at the driving end would be best but in any of these cases you are no longer using a balanced connection and the unbalanced should be preferable.

As an aside here, many balanced items work unbalanced internally and use a "line receiver" and "line driver" IC to convert the unbalanced to balanced at the source and then convert the balanced back to unbalanced at the receiving end. These IC's consist internally of usually a 3 op amp circuit. Sometimes in fact 3 op amps are indeed used at each end in place of the specialised chip... results are about the same.

My point is? Well in all such equipment using the balanced input and output means in effect taking the unbalanced signal and then feeding it through 3 op amps at each end! Hardly minimising the signal path....

DAC's tend by their nature to have true balanced outputs anyway (even if no balanced output is provided in your DAC the DAC IC usually works in balanced form) and so in nearly all cases a DAC with balanced outputs IS truly balanced, but the same is not true of pre amps and especially power amps. It is certainly possible to do both in true fully balanced form but it greatly adds to cost and complexity and makes things a bit awkward to use them unbalanced so the "cheat" method which adds the 3 extra op amps at each end is much more common.

[Arkless Electronics]

Sounds like a good offer to me Balanced phono stages must be pretty rare.

Pretty rare yes but there are a few around. It was just me thinking out loud and seeing if there was any interest really...

[hifinutt]

i find that it totally depends on the equipment I am using whether rca or xlr is best . I have 2 very high amps here at the moment and prefer the rca connection [using eichman rfc mercury rca ] as opposed to my rfc hyperion furutech xlr

[Arkless Electronics]

i find that it totally depends on the equipment I am using whether rca or xlr is best . I have 2 very high amps here at the moment and prefer the rca connection [using eichman rfc mercury rca ] as opposed to my rfc hyperion furutech xlr

The cables themselves make no difference whatsoever (bizarrely some disagree here apparently). In fact, for cable believers, balanced should theoretically cancel out any "cable sound" as it is the difference between the + & - ("hot and cold") inputs that is amplified by a balanced amplifier and in theory it should be deaf to anything applied identically to the "hot and cold" inputs. In many cases though, as I said above, you have a total of 6 op amps per channel added to the signal path when using balanced. Actual circuit diagrams would need to be consulted to see if particular models do things this way or not.

[Spectral Morn]

Problem here is not all kit with XLR outs and ins is actually balanced. Balanced kit is dual differential. Using XLR outs may not sound better than RCA, but much depends on the circuit topology and the way the XLR outs and ins have been implemented.

[brucew268]

What was said about Balanced circuit design issues in DAC's, preamps, and amps agrees with what I've heard before, and I take it on board. In fact, y preamp's Balanced input does use 3 more opamps than the Single Ended input... but the result still sounds better.

No one has yet offered any guesses about why the XLR out of the DAC sounds better than its RCA out, even though the IC is a 1 meter RCA.
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