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DACs - balanced, unbalanced? I'm Confused!

AW61

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I know this has been discussed to some extent but I can't quite find the answers I'm looking for so here goes...

Can someone explain the benefits of balanced vs non balanced in a DAC (for my system)?

My situation is

Chromecast Audio Optical output --> DAC (yet to be chosen) --> RCA input of Active Speakers (5m cable run)

So if I had a balanced DAC and used the XLR outputs I would need to use a XLR to RCA adaptor at some point.

I have read things like this (here describing SMSL M300):-

"If you are going to utilize the balanced output of M300 mkii then it can be a very good option. But its RCA output performance much worse. "

And

"XLR’s are promoted by SMSL to be the balanced output. They can squeeze out 4.2Vrms current while the RCA output is rated at 2.1Vrms only. I conducted my test using the LSR305P MK2 active near-field monitors. I used both XLR and RCA. In my opinion, the layering and staging is the real difference between the two input types. The XLR has a clear superiority here."


So are we talking the benefit being reduced interference on XLR due to being a shielded cable?

But then I think there are shielded RCA cables so these could be used on an RCA output?

Or is it just that XLR just higher output (is that necessarily a good thing?)



You get the point about why I am confused….

For my length of run does it mean that shielded cable is the essential thing, whether true balanced XLR or RCA? I’m driving speakers here not headphones.


I MAY add a preamp after the DAC which I realise adds another layer of complexity. I’ll do so if I do not have adequate volume control just using the CCA only.

Then – passive or active preamp and what happens with balanced/unbalanced then?

Help!
Thanks
 

BDWoody

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You get the point about why I am confused….

Absolutely, and welcome!

Here's a video our host put together on this very subject. Might help as a starter.


 
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AW61

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Here's a video our host put together on this very subject. Might help as a starter.
Thanks for such a quick reply!

I've watched this and it explains quite a bit, although he was talking about balanced/unbalanced on headphone amps rather than DACs.

I think because I'm only driving speakers and don't have multi element connections ( ie PC/USB going into DAC etc) then the risk of ground loops is low so no real need for balanced for that
fwiw I've never previously seen Hi-Fi equipment with anything other than RCA - except NAIM and B&O but they are special cases!

I don't think I need the higher voltage (4V) that balanced can put out?

So I'm not sure that a DAC's balanced outputs give any advantage over RCA for my situation, unless:-

- my required cable 5m run length means balanced will reduce losses/interference (but I still have to convert o RCA at the speaker end)
- or there in something intrinsic in the design of a given DAC that means the XLR outputs just have a higher sound quality

of course I may be completely wrong - what do you think?
 

radix

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If your speakers are only single ended (RCA), then running balanced to them is only beneficial if you use a transformer adapter at the speaker side. The transformer will maintain the noise immunity. If you use a simple converter, it only takes the + phase and ignores the - phase, so there's no added noise immunity. I'd personally make my own RCA cables with good RG6 cable.

Which active speakers do you have?

Are you using a 5m RCA to them right now and it's OK? If it's OK now, it will likely be OK with a new DAC.

As has been pointed out, advantages are:
- A lot more noise immunity
- Easily fix ground loops by floating pin 3 at the speakers.
- Higher signal level
 
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AW61

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If your speakers are only single ended (RCA), then running balanced to them is only beneficial if you use a transformer adapter at the speaker side. The transformer will maintain the noise immunity. If you use a simple converter, it only takes the + phase and ignores the - phase, so there's no added noise immunity. I'd personally make my own RCA cables with good RG6 cable.
Thanks - and presumably without a transformer adapter you don't get 4V either (ie reduces to the 2V?)

I'd personally make my own RCA cables with good RG6 cable.
Good suggestion.

My other puzzle is that I want to feed a sub. A neat way of doing that would be if both the RCA AND XLR outputs of a DAC were simultaneously active - is that generally the case?
Speakers are Beolab 17's
 

radix

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Thanks - and presumably without a transformer adapter you don't get 4V either (ie reduces to the 2V?)


Good suggestion.

My other puzzle is that I want to feed a sub. A neat way of doing that would be if both the RCA AND XLR outputs of a DAC were simultaneously active - is that generally the case?
Speakers are Beolab 17's
Hey B&O! I still have some penta 5 and 4500s.

You should get a DAC/PRE that has separate sub outs, or use a minidsp 2x4 HD or minidsp DDRC-24 HD (the latter just has more software). These are a 2-channel to 4-channel DSP. You can do full room correction and crossovers with them. That way you can, say, do an 80 hZ (or 120 hz?) high pass to the beolab and a corresponding lowpass to the subs. I'm not sure where the 17s should be crossed. If you get the DDRC-24HD, it include Dirac software that automates room correction.

What I do in some rooms, like with my Beolab pentas, is us a Raspberry Pi 4 + Ropieee XL as the transport, then USB to the minidsp, then RCA coax to the speakers.

The other way of doing it, depending on your subs, is to go from the DAC to the subs, then the subs to the speakers. Some (many?) subs will properly cross-over the line level to the speakers based on how you setup the sub.
 

litemotiv

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So I'm not sure that a DAC's balanced outputs give any advantage over RCA for my situation

It most likely won't.

One thing that you should be aware of is that the Chromecast Audio Toslink suffers from a high amount of jitter, so when looking for a DAC you may want to get one that deals with that properly. See also:


Another option would be to use a better source than the Chromecast Audio and the DAC will be less important.
 
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AW61

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One thing that you should be aware of is that the Chromecast Audio Toslink suffers from a high amount of jitter
Yes it does! But I use the app Hi-Fi Cast and (along with Roon) I believe this deals with the jitter.

Quote from the above link

"EDIT: bit-perfect playback is also supported in Android apps like Hi-Fi Cast. See: https://audiosciencereview.com/foru...omecast-audio-digital-output.4544/post-102185. So you are not just limited to Roon."

Nevertheless, even if so, I agree it would be a good precaution to choose a "jitter-neutralising" DAC
 
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AW61

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You should get a DAC/PRE that has separate sub outs, or use a minidsp 2x4 HD or minidsp DDRC-24 HD (the latter just has more software). These are a 2-channel to 4-channel DSP. You can do full room correction and crossovers with them. That way you can, say, do an 80 hZ (or 120 hz?) high pass to the beolab and a corresponding lowpass to the subs. I'm not sure where the 17s should be crossed. If you get the DDRC-24HD, it include Dirac software that automates room correction.
You mean effectively splitting the RCA into two?

The other way of doing it, depending on your subs, is to go from the DAC to the subs, then the subs to the speakers. Some (many?) subs will properly cross-over the line level to the speakers based on how you setup the sub.
Yes - I know some subs have RCA in/out
 
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AW61

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One thing that you should be aware of is that the Chromecast Audio Toslink suffers from a high amount of jitter, so when looking for a DAC you may want to get one that deals with that properly.
Can you tell me how to identify such a ("jitter neutralising") DAC from the reviews here?
 

radix

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You mean effectively splitting the RCA into two?

The minidsp can work like an active crossover. It can split the frequencies so the speakers only get high pass (e.g. over 80 hz) and the subs get low pass (e.g. <= 80 hz). You can also mono-sum the subs or keep them L/R.

You can use software like REW or Dirac to measure your room response and EQ the audio to help flatten out the room modes.

Most modern subs will also do the active crossover to split the signal. I would bet something like an SVS 3000 micro would work well with smaller speakers like the Beolab 17. They have internal crossovers for the speakers. It would be good to check the SPL outputs to make sure they are in the ballpark of each other, but on a glance I think they are
 
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AW61

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Most modern subs will also do the active crossover to split the signal. I would bet something like an SVS 3000 micro would work well with smaller speakers like the Beolab 17.
Yes. Actually been looking at the SVS 2000 and it does have a frequency filter ie the signal path becomes DAC to sub to speakers... so no need for a RCA splitter in that case.
 

radix

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Yes. Actually been looking at the SVS 2000 and it does have a frequency filter ie the signal path becomes DAC to sub to speakers... so no need for a RCA splitter in that case.

Not to spend your money, but the PC-2000 might look nicer with those B&O speakers. Anyway, SVS subs seem to be a very good value for quality and price.
 

litemotiv

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Can you tell me how to identify such a ("jitter neutralising") DAC from the reviews here?

I'm not sure if jitter rejection on the optical port is regularly tested on ASR, most of the models may be tested on the coax port so that wouldn't give you all the needed information. However if a DAC performs very well on coax then you can generally assume that optical will perform well too., so i think that's a pretty good metric as a baseline.

Some of the more expensive models have a masterclock that performs de-jitter, this is a clear sign that jitter rejection will be (very) good. But it depends on your budget and perhaps other factors such as DAC features if those models will be a good match.
 

kongwee

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Your SMSL is truly differential that why drop in quality, no doubt about it. There are product offer XLR that drop quality in XLR. Normally they won't give the different impedance value on both XLR and RCA.
 
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AW61

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If your speakers are only single ended (RCA), then running balanced to them is only beneficial if you use a transformer adapter at the speaker side. The transformer will maintain the noise immunity. If you use a simple converter, it only takes the + phase and ignores the - phase, so there's no added noise immunity. I'd personally make my own RCA cables with good RG6 cable.
Ok – to pick this up again – bit of a reset - I now have a DAC, the SMSL DO200.

This has both RCA and Balanced outputs that can be used simultaneously so no need for a splitter to drive any sub.

This then returns to the original question – is there any benefit in using the XLR outputs on the DAC, running the 5m to the speakers and using a simple XLR to RCA adapter at that point.

So, in summary:-
- Is ALL the benefit of XLR lost by using a simple adapter (vs just using the RCA outputs and a 5m RCA to RCA cable)?

- If so, then what’s the advantage of a home-made RCA cable using RG6 vs a commercial eg Van Damme cable (is the fact that the RG6 is coax and advantage?) ....or is it just cost?
 
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AW61

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To partly answer my own questions (from further reading)

1/ The benefits of XLR vs RCA (at least from a DAC) are:
- Eliminates possibility of hum/noise
- Higher voltage
- DAC XLR output may be higher quality than RCA

2/ So in any case where the downstream equipment from the DAC (ie amplifier) only has RCA inputs, a converter to RCA has to be used. Even if the converter is at the end of the balanced cable at the amplifier end, the net result is effectively just a RCA to RCA cable…. so the benefits of XLR are lost…unless the XLR output was intrinsically higher quality, even if reduced to single ended.

3/ The benefit of noise/hum elimination would be retained if something like the ART Cleanbox pro were used at the end of the XLR cable, such that just a short length of RCA was run from that. But I guess it would only be required if noise/hum was found to be present without it. https://www.thomann.de/gb/art_cleanbox_pro.htm

Do you agree that the above is true – please say if otherwise, thanks!
 

flz

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To partly answer my own questions (from further reading)

1/ The benefits of XLR vs RCA (at least from a DAC) are:
- Eliminates possibility of hum/noise
- Higher voltage
- DAC XLR output may be higher quality than RCA
I'm also interested & confused by this issue. Hum/noise and higher voltage are not issues for me. The XLR output being higher quality than the RCA output in the same DAC would be of concern. I've noticed in many of Amir's tests of DACs with balanced outs, the balanced has slightly higher SINAD scores than the RCA. Is that what is meant by higher quality? If the SINAD difference is for example 121 vs 119 - that makes no audible difference - right?

And is it correct to say lower voltage of the RCA output can be totally compensated by turning up the volume on pre-amp/int amp/powered speaker that is connected to the DAC? Unless if you don't think it's loud enough even at max volume.
 

kongwee

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I'm also interested & confused by this issue. Hum/noise and higher voltage are not issues for me. The XLR output being higher quality than the RCA output in the same DAC would be of concern. I've noticed in many of Amir's tests of DACs with balanced outs, the balanced has slightly higher SINAD scores than the RCA. Is that what is meant by higher quality? If the SINAD difference is for example 121 vs 119 - that makes no audible difference - right?

And is it correct to say lower voltage of the RCA output can be totally compensated by turning up the volume on pre-amp/int amp/powered speaker that is connected to the DAC? Unless if you don't think it's loud enough even at max volume.
In audiophile world, not all XLR are better than RCA. Spectral Audio recommend using RCA than XLR unless you need to wire pre and power off more than 10 meter. Some of the brand I know don't sound good at XLR than RCA. Even being used in pros. Actually from product description you can know about the amp run better on XLR or RCA. If product boasting about differential amplifier, XLR is better used.
 
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