Blog » Hot Topics » Debate this – XLR or RCA?
February 19th, 2014 0 Comments

Debate this – XLR or RCA?

rca v xlr

Audiogoner Elegal writes:

It was recommended, in another post, that I try a difference IC cable. I was considering the audio quest columbia XLR. ( I am currently using xlr cable between by c2300 preamp and mc275 amp). However, I then read that xlr cables only provide a real benefit if you are using balanced cables throughout your entire system, which I presume means from my turntable into my preamp. Is this true? Because if it is, perhaps I should switch to RCA. That is, my tonearm cable ends with RCS cables. In fact, my pre-amp does not have xlr inputs for phono (though it has them for everything else).

He’s pleading with the wise Audiogon community to point him in the right direction – XLR or RCA?

Jmcgrogan2
The real benefit of using XLR cables is in the fact that it allows you to utilize fully differential equipment designs, which will lower the noise floor. That being said, just because you are using XLR cables does not mean that your equipment is a fully differential design, it could be a single ended design that simply has XLR inputs and/or outputs on the unit for flexibility. If the unit is not a fully differential design, you will not receive the benefits of running XLR cables.

Also, yes, to receive the benefits of running fully differential, you should run all the way from source through amplifier to maintain this ‘advantage’. Any break in the chain, anywhere in the chain, and using XLR interconnects becomes rather pointless.

According to the McIntosh website, neither the C2300 nor MC275 are fully differential designs. The XLR inputs and outputs are simply cosmetic, therefore should hold no advantage.
Almarg
This is one of the rare occasions when I must very respectfully disagree with my learned A’gon colleague and friend Jmcgrogan2, although the opinion he expresses is shared by many audiophiles.

Elegal 02-17-14
I then read that xlr cables only provide a real benefit if you are using balanced cables throughout your entire system, which I presume means from my turntable into my preamp. Is this true?

My answer is that it is not necessarily true. Regardless of whether the components in the system are internally balanced or not, and regardless of whether all of the interconnections in the system are balanced or not, a balanced interface between any given pair of components is inherently less susceptible to noise that may be introduced as a result of ground loop or other effects. And in referring to “noise” I am referring not just to noise that may be audible as such, but also to the possibility that noise that may be introduced at frequencies which are too high to be audible may have audible consequences, by “intermodulating” with signal within the components.

On the other hand, it is not uncommon for the XLR interface circuits of components that are not internally balanced to be sonically inferior to the RCA interface circuits of those components.

The bottom line, IMO: Which interface would be best to use in your particular case cannot be predicted with any certainty. Hopefully someone will chime in who has experience making that comparison with the same or similar McIntosh components, as other opinions stand a very good chance of not being applicable. IMO, of course :-)

Regards,
— Al

Mofimadness
I would like to add to what Al says above in that the XLR connector itself is much better than most of the RCA connectors. IMHO, better than even the locking RCAs. Another potential added benefit to using balanced cables.

Elegal
Thank you MOFI; AL; and JMC. I feel like I should send you guys some LP’s for your help

Stringreen
There is a minor benefit in using XLR even though the component is not internally balanced….the big benefit is when one does it right.

Jmcgrogan2
No worries Al, I am sure that you are right. I would not disagree with you. I am simply repeating what I have been told, it could very well be misinformation, as this hobby is filled with it.

To be honest, I have gone both routes, running a fully differential system with all XLR cables, and running all single ended with RCA’s. I cannot say that I have had a noise issue with either. I think I may have convinced myself the balanced was quieter, when I had it, but now that I’m back running SE again, and have no noise issues, I’m convinced I was just buying the hype. ;)
There may have been more measured noise, if I had the proper instruments to measure. If there was any difference in noise level, it was not audible, to me anyway.

I do agree with Mofi that the XLR connectors make for a superior connection though.

Elegal…no need to send LP’s, that’s why we’re here….unless you have extras laying around that you are just looking to give away. ;^)

Czarivey
if preamp and amp are balanced you’ll get most of most benefit and cheap xlr wire will sound much better than expensive rca

Elizabeth
I use a mix of RCA. XLR in my system.
Partly what sounds better. Plus really long cables are usually better in XLR if that can be done.

Jburidan
My Cary SLP 05 sounds better with RCA, so that’s what I use.

Rsimms
I have a Calypso tube preamp. It has fully balanced differential inputs and outputs. When I use the differential inputs and outputs I loose much of the tube character of my preamp. I have a tube preamp to get the euphonic tube sound to music. Tubes improve the emotional impact and add a wonderful organic character to the music. The differential inputs and outputs seem to be clearer and possibly more technically accurate versus the single ended ones. I guess that is due to the noise and distortion canceling effect of true differential circuitry. I use the single ended inputs for music and use the differential inputs for HT. I gather this only applies with true differential circuits and probably won’t apply to Macintosh. If so, then I would think the XLR connections would be best whenever they are available. Of course, the only true answer is your own ears. This is just a guide to know what kind of things to listen for.

Bob

Effischer
I just changed out some antique 25 foot RCAs running from my C50 to my MC302 with 5 meter XLRs and dropped the noise floor substantially. Immediately noticeable. Can’t give you a critique of the sound quality yet as I haven’t been able to do any serious listening, but so far I’d say I made the right move. Even though you are all tube, I strongly suspect you will find the same thing. Dropping the noise floor always allows more fully resolved fine detail.

Kijanki
Bob, differential amplifier can suppress even order harmonics (associated with warm sound). Voltage of each output can be seen as:

Vp=a1*Vi+a2*(Vi^2)+a3*(Vi^3)+a4*(Vi^4)+a5*(Vi^5)+ …..

Vn=a1*(-Vi)+a2*(-Vi^2)+a3*(-Vi^3)+a4*(-Vi^4)+a5*(-Vi^5)+ ….

where “a2, a4 etc” are even order coefficients. Since polarity of the input signal will be always positive (always raised to even power) for even order harmonics they appear same on each output and will be removed (assuming identical gains).

Vp-Vn=2a1*Vi+2a3*Vi^3+2a5*Vi^5….

The other problem might appear when gains are not exactly even because it can convert common mode noise/interference into normal mode signal.

Elegal, I found more of a difference using an upgraded cable than between using XLR vs RCA connections. Using the same upgraded cable into my C2300, I preferred the XLR. As you know if you are using the phono stage on the C2300, you need to use RCA

What does your experience tell you, Audiogoners? Tell us in the comments.