RCA cables and noise

I see a lot of dacs that have rca cables and I’m wondering because I know xlr is better but my studio monitors have xlr snd rca, does anyone use rca a cables with ardour and have good performance with little or no extra noise added. I’ve seen some xlr cables with thick shielding and even some that have a balanced connection at the other end of the cable from the rca

The RCA connections are used for line level signal sent between one amplifier (e.g. interface output) and another one (active monitor input). The signal is strong enough and the impedances are matched well enough that noise is usually not a problem, unless one uses a really long cable.

XLR advantages are important for weak signals (like those from microphones or guitars), very long cables and where a ground loop might be a problem.

I don’t think connecting studio monitors with RCA would be any worse than via XLR in any usual circumstances.

Some/many DACs also use rca connectors for s/pdif rather than audio.
But assuming the rca at both ends is for audio (and not digital signal) then there may not be a problem.
This certainly isn’t anything to do with Ardour, just your hardware.

What’s cool is from khadas, which has balanced RCA cables

Personally I disagree. While yes the cables could theoretically carry a balanced signal, just using the cables themselves does not make the signal balanced, you would have to have support on at least one end (ideally both ends) for the signal to be balanced.

Along with that this still has the annoying problem of it not being a locking connector as well. Realistically if you have balanced support I don’t see much reason to go this route instead of XLR, where you have much higher chances of having balanced support on both ends.


Ok, but even if the other end is xlr?

If you plug it into a standard RCA jack, it will be unbalanced. You can cheat this a little if the RCA is the transmitting end, and it is plugged into a balanced input, if you customize the wiring so that shield and signal go to pins 3 and 2 respectively as it will act somewhat balanced in that regards as the receiving end will still incorporate the differential amplifier and cancel out noise that is induced on both conductors simultaneously, but this is not a standard wiring.

End result, 99.999% of all RCA jacks on equipment are unbalanced, and using a balanced cable will not change that. And realistically, it may be 100%, as I have never in my life seen a balanced RCA anywhere, must less mounted on equipment.


The cable I linked j. My previous post, it had a new pin on the rca. Like a little circle or something. But I think I understand what your Saying, wouldn’t it still be better if you had that specific setup snd was using their rca cable that is unique and not just rca to xlr but the rca cable itself has special pin and the dac has that same special slot for it.

I understand that generally all rca cables and jacks are unbalanced but then I think what’s the point of this new special implementation

Standards are wonderful, non-standard equipment is %^&*!!! The last thing I need is another situation that requires an adapter. I already make enough TRS to XLR cables as is. RCA connectors are archaic… but cheap and so lots of cheap consumer grade equipment still uses them. (Audiophile is the same a consumer grade… with gold contacts) Any time someone goes non-standard… someone is picking your pocket.

Lots of equipment have balanced I/O on TRS 1/4" or 6.3mm connectors (basically headphone connectors, but used for line level I/O). That “balanced RCA” looks like it has all the downsides of RCA connectors, plus isn’t compatible with anything else.
The comparison chart is so misleading it makes me think they did it intentionally. If you don’t like the size of the XLR connectors, the obvious comparison is mini-XLR3, not mini-XLR5, and no one uses 3.5mm connectors for balanced line level signals, but balanced on 6.3mm TRS connectors is super common, yet not mentioned in their chart. Typical consumer audio goofy solution to a problem that doesn’t really exist.

I myself prefer xlr but I know there are some nice dacs out there but they don’t have xlr and I always wondered why balanced outputs on these dacs are not standard .

Build a bigger box… I don’t have anything against 1/4 in TRS really. But adding yet another connector (balanced RCA) is just not needed. Of all the panel/pcboard mount connectors I have bought recently, the RCA have been the cheapest. I might add that for anything I have used on stage, the RCA stuff has been the first to loose their ground and hum too. The only reason to design such a thing is to charge more without spending more on the connectors. Just a cheap out. They are fine for the home stereo… plug in once and never touch till replacement.

Home equipment was designed to be a cheap as possible, and for some reason most home equipment even with outrageous prices has not bucked the original 1950’s design of using RCA connectors. Some has, you can get some high end home gear that uses XLR connections, but most doesn’t even though there is no technical justification for using unbalanced connections on anything except the cheapest equipment.

Just for compatibility with the widest range of equipment. With unbalanced connection any difference in voltage between the grounds inside the circuits is in series with the signal, so you will always have some amount of 60Hz hum detectable in unbalanced connections (in the US, 50Hz in Europe and parts of Asia). Usually not enough to be annoying, but you can always see it on a spectrum analyzer.

There is a way to wire XLR connections improperly inside of equipment so that even with balanced connections the equipment is susceptible to hum, so there is some improperly designed pieces of equipment which will still hum even when using balanced connections, but that is getting pretty rare these days since the proper way to design balanced equipment has been widely publicized since 1995.
If you want to get into the details then get the June 1995 issue of the Journal of the Audio Engineering Society, the entire issue was dedicated to proper shielding and grounding.
Unfortunately the website was reorganized recently so there isn’t a way to give a direct link. Go to the aes.org web site, then to the publications store:
AES web store
That link may be through the members portal, I’m not sure it will work if you aren’t logged in, but you can try it.
Over on the left side menu select “Journal Issues,” then “Shields and Grounds (Downloadable PDF)” at the bottom of the journal issues store page.
It is only $10 if you have a membership, or $15 if you don’t. It is definitely worth $15 just for the crash course in properly wiring up audio equipment. A lot of the information you can collect elsewhere, but I think it is worth it having everything all together in one place.

So there is cable noise with unbalanced that I will hear, interesting.

Whether you hear it or not will depend on amplitude of the noise, gain staging, noise floor of the equipment, acoustic noise floor of the room, etc. It obviously isn’t much of a problem in practice for consumer playback systems because it is still in use for 99% of home audio systems. Most houses have enough acoustic noise that any interference gets lost in the background.

The likelihood that power line related noise will be audible generally scales in some way with length of connections, and number of connections, which is why studios almost exclusively use balanced connections, since you generally have many different connections to the main console, some running across a building or between buildings (and why the phone system always used balanced connections, since you had connections running potentially for miles with dozens to hundreds of houses or apartments connecting to the switching office).

You can check the magnitude of noise in your system with some type of spectrum analyzer program (I like JACK and ALSA Audio Analyzer (JAAA) from Fons Adriensen):
Kokkini Zita downloads
If you are running jackd connect the output of your audio chain to the input of JAAA, and zoom in on the 60Hz region. That will just give you the level relative to digital full scale, you will need to know your acoustic gain from electrical level to SPL to calculate the resulting acoustic level in your room, but the zita tools have everything you need for that (except an SPL meter, you would either need a calibrated hand held device, or some way to calibrate a microphone/input interface to a known SPL reference).

I guess I was more concerned in the realm of mixing tracks. But I can look into it if I ever use rca on a system to mix