XLR-to-RCA Cables

[jsrtheta]

This is my first actual thread-starting post. I haunt these precincts mainly for what I can learn, and occasionally pipe up about a topic here and there.

I have nothing like the technical knowledge, let alone understanding, of most here. I do thank you for everything you've taught me!

But I have what I think is a simple question: I bought a pair of female XLR-to-male RCA cables, though I don't use them, later opting for an ART Clean Box Pro for conversion from XLR to unbalanced RCA (it goes the other way, RCA to XLR, too). But I need a basic understanding of what actually happens, electrically, with the cables I originally bought when they are used without any other impedance-matching, etc. device. I.e., with a balanced output component to an unbalanced input component.

Thanks in advance.

 

[DonH56]

Usually something like this:

 

[Wombat]

FYI:

Rane Note 110 Sound System Interconnection

Rane Note 151 Grounding and Shielding Audio Devices

 

[jsrtheta]

Usually something like this:
View attachment 27967

That I knew. (Not being snarky, just trying to focus.) I'm interested in how the signal is affected.

 

[jsrtheta]

FYI:

Rane Note 110 Sound System Interconnection

Rane Note 151 Grounding and Shielding Audio Devices

Thank you! I will read these (I've bookmarked them). As Stephen King taught me, "Curiosity killed the cat, but satisfaction brought him back".

 

[March Audio]

If you are feeding an unbalanced RCA into a balanced input this is best practice.

Impedance matching is not required and you still benefit to a degree from the common mode noise rejection inherent with balanced input.

 

[DonH56]

That I knew. (Not being snarky, just trying to focus.) I'm interested in how the signal is affected.

I have not looked at the Rane notes in years but they are probably a good resource.

Fundamentally you are unbalancing the signal and thus throwing away common-mode (noise) rejection -- it may be more sensitive to noise. Leaving the shield unconnected at one end breaks the current loop for external noise so you still get some benefit from the cable. At the source and receiver, it depends upon the circuit implementation. For receivers, CMRR (common-mode rejection ratio) may drop from 40~80 dB to 6 dB or less. That only matters if there is enough common-mode noise to cause problems in your system. IOW, you probably will not notice.

It also means the signal is no longer differential and so even-order harmonics are no longer cancelled so distortion may be a little higher, Again, almost certainly inaudibly.

Finally, again depending upon the circuit, noise may be a little higher running single-ended. You theoretically lose about 3 dB in SNR. Does it matter? Again, probably not.

I have a article talking about ground loops and differential circuits someplace on ASR (need to create a ToC post again) but Rane probably does it better.

Sometimes you (and I) are better off not knowing too much. Just plug it in and, if it sounds OK, done.

HTH/IME/IMO/etc. - Don

 

[jsrtheta]

I have not looked at the Rane notes in years but they are probably a good resource.

Fundamentally you are unbalancing the signal and thus throwing away common-mode (noise) rejection -- it may be more sensitive to noise. Leaving the shield unconnected at one end breaks the current loop for external noise so you still get some benefit from the cable. At the source and receiver, it depends upon the circuit implementation. For receivers, CMRR (common-mode rejection ratio) may drop from 40~80 dB to 6 dB or less. That only matters if there is enough common-mode noise to cause problems in your system. IOW, you probably will not notice.

It also means the signal is no longer differential and so even-order harmonics are no longer cancelled so distortion may be a little higher, Again, almost certainly inaudibly.

Finally, again depending upon the circuit, noise may be a little higher running single-ended. You theoretically lose about 3 dB in SNR. Does it matter? Again, probably not.

I have a article talking about ground loops and differential circuits someplace on ASR (need to create a ToC post again) but Rane probably does it better.

Sometimes you (and I) are better off not knowing too much. Just plug it in and, if it sounds OK, done.

HTH/IME/IMO/etc. - Don

Thanks, Don! This helps a lot in my understanding. I knew, roughly, how it worked, but this nails it. And, I learned some things I didn't know. Thanks again.

 

[DonH56]

Link to ASR article: https://www.audiosciencereview.com/...d-balanced-unbalanced-and-all-that-jazz.1352/

 

[jsrtheta]

Link to ASR article: https://www.audiosciencereview.com/...d-balanced-unbalanced-and-all-that-jazz.1352/

Now bookmarked. Thanks!

 

[davidho]

Usually something like this:
View attachment 27967

Does it applied to both Male and Female XLR connectors ? Thanks .

 

[solderdude]

The drawing ONLY applies for RCA TO XLR
Not for XLR to RCA.

 

[Speedskater]

XLR out to RCA in is more complicated. There are three & a half types of XLR output stages and no one style of adapter will work for all three.

 

[Senegalas]

Usually something like this:
View attachment 27967

Can this demage a balanced dac? Because I see that pin 1 and 3 are shorted in this case? I am talking about scenario when converting bal to rca. And is final output of such conversion 2 or 4V?

 

[DonH56]

Can this demage a balanced dac? Because I see that pin 1 and 3 are shorted in this case? I am talking about scenario when converting bal to rca. And is final output of such conversion 2 or 4V?

You can use that for an RCA source (output) to an XLR input. It should not be used to connect an XLR output to an RCA input; the (-) signal pin is usually left floating on the XLR's output. In some cases it may be best to leave the (-) pin floating either way.

 

[bigguyca]

(1) Can this demage a balanced dac? Because I see that pin 1 and (1) 3 are shorted in this case? I am talking about scenario when converting bal to rca. And is (2) final output of such conversion 2 or 4V?

(1) YES

(2) Balanced: (for example): 4V in, 2V on pin 2, -2V on pin 2

RCA: pin 2 of balanced connected to center pin of RCA, 2V output

 

[DannyBukem]

Hi Guys, This topic is an interesting one as i think i may have an issue caused by an XLR to RCA cable....

I have a Denon DJ controller than connects to my Yamaha 3080 AVR via XLR no problems.

But then, i connect from 2080 XLR out to RCA in on my Rotel Power amp, therefore sending balanced into an unbalanced RCA.

What i notice is my REL 212SE Subwoofer which is connected via High Level on the back of the Rotel Power Amp, it seems to create a low end distortion which makes the subwoofer rattle.

If i connect 3080 to power amp using RCA, it doesn't appear to happen.

Do you think the XLR out is sending to Power amp RCA in with an increased gain ?

 

[AnalogSteph]

It is possible that the XLR > RCA cable used is shorting half of the output stage to ground, upsetting it - check cable pinout. Generally adapting this way round only makes sense if it is the only way to connect two devices at all, as reaping the benefits of a balanced connection hinges on the balanced input stage. XLR > RCA thus has no advantages over RCA > RCA.

 

[DannyBukem]

I am going to stop using it, i think it may be doing more harm than good!

 

[AudioScience Enthusiast]

I have a DAC that has XLR outputs, but my amp only has RCA inputs.

Aside from no additional benefits of using XLR > RCA, will it damage the equipment if the incorrect cables are used? Like these: https://www.amazon.ca/gp/product/B0956JXSSZ/ref=ox_sc_saved_title_2?smid=AGUI0L2IM8WT3&psc=1