XLR vs. RCA

[adk highlander]

I am waiting patiently for my new pre pro (Onkyo Pro PR-SC885P) and I want to get opinions on if it is worth it to upgrade my connectors to XLR.

I have a perfectly good set of rca (bestdealcables) but part of me thinks that if I have the ability to use the balanced cables that I should. Am I just being stupid or will I actually hear the difference?

Also if anyone can give a good explanation of what the supposed advantage is I would like to hear it. I have a set of monster rca cables that say balanced on them but I did not think that was possible.

Thanks.

 

[j_garcia]

If it were for long runs, I would say XLR, but for short runs I am not sure you would hear a difference, since it is really over long distances where you will benefit from balanced cables. The difference between them is that XLR are balanced which means three conductors instead of two for carrying the signal (+, -, ground); which makes it easy to "reject" noise on the line that is not signal. RCA are unbalanced and have only 2 conductors which means one of the conductors is used to carry both signal and ground. When an RCA cable says balanced it is a bit of a misnomer - it likely means 3 conductors with ground only connected on one side (making the cable directional from source to amp) so it isn't a true "balanced" condition. The RCA interconnects I use are like this, though that wasn't a selling point for me, they just happened to be that way.

 

[sjsmithjr]

Unless your in a really noisy (EMI) environment, I can't think of any advantage of switching over to balanced (XLR) connections. Some people like it for the "cool/pro" factor and some people swear they can hear a difference. There's usually no technical reason for using balanced connections in a home environment. But if it makes you happy...

Balanced cables require three conducters so I'm sure the marketing department has taken liberties with the definition of "balanced".

-Sam

 

[adk highlander]

I think some of it is the cool factor. I will have short runs of 1.5m or less so distance is not an issue. Thanks J for the quick explanation that makes sense.

I got a quote from a ex engineer who makes nice cables (canare wire, NEUTRIK connectors) with the color coded connectors and wrapped cables. He gave me a good price for all seven and knowing me after I get it the preamp I will probably order them.

 

[j_garcia]

I haven't had good luck with Neutrik connectors actually; I got a set of nice custom cables with the retractable Neutriks and one connector on each cable broke.

Bluejeans also sells 5, 6, 7 and 8 ch bundles.

 

[adk highlander]

Hmm. I'll see if he has anything other than the Neutriks. I think he is using the better cable that they listed and was cheaper. I will look at their connectors and see what they use.

Thanks.

 

[sjsmithjr]

Neutrik was having a problem with Chinese counterfeits; don't know if audio products were part of the problem or not. Has anyone tried the successor to the X series, XX? They're supposed to have better strain relief.

-Sam

 

[highfihoney]

Quality XLR cables are dirt cheap,in fact they are cheaper than off the shelf Monster RCA cables,i'll not go into a big speel about why you should use balanced cables but you should be aware that for about $30 USD you can go to any guitar shop & pick up a great pair of XLR's.

The bigger question here should be about the preamp you have ordered,is it a truly balanced preamp ,all preamps that have the ability to use XLR connections are not nessecarily a balanced preamp & the XLR connections are not ballanced connections, but are merely RCA connections converted to use XLR,there is no benifit what so ever to running Balanced connections with these types of preamps.

 

[adk highlander]

Great observation that I did not realize. Here are the specs listed:

General
Input Sensitivity and Impedance
Line: 200 mV/47 k-ohms
Phono MM: 2.5 mV/47 k-ohms
Output Level and Impedance
Rec out 200 mV/470 ohms
Phono Overload 70 mV (MM, 1 kHz, 0.5%)
Frequency Response 5 Hz-100 kHz/+ 1 dB, - 3 dB (Direct mode)
Tone Control ± 10 dB, 50 Hz (Bass)
± 10 dB, 20 kHz (Treble)
Signal-to-Noise Ratio 110 dB (Line, IHF-A)

If I am correct it only has line listed and if there were two different inputs should there not be one for RCA and one for XLR? It does have balanced inputs as well. One would think that they would be properly setup if that were the case.

 

[highfihoney]

I cant say for sure being that i know nothing of the preamp your buying but from looking at the specs you listed the preamp is not a fully balanced preamp,either the preamp is not fully balanced or they totally forgot to include the specs for balanced connections which is highly doubtfull.

Believe it or not there are many preamps on the market that have XLR connections on the back but the connections are not balanced,they are tied in directly to the standard RCA connections & only offer the convience of choosing between the two connections but do not offer any of the advantages of running balanced connections.

As an example of what specs should look like for a fully balanced preamp here are the specs for my current preamp which is a balanced unit.

Output voltage.

2.5 VRMS unbalanced (RCA)

5 VRMS balanced (XLR)

Maximum voltage output.

10 VRMS unbalanced (RCA)

20 VRMS balanced (XLR)

Output impendance.

240 Ohms unbalanced (RCA)

480 Ohms balanced (XLR)

Input impendance.

High level.

22K Ohms unbalanced (RCA)

47K Ohms balanced (XLR)

Sensitivity.

450 MV unbalanced (RCA)

900 MV balanced (XLR).

As you can see there are quite a bit more differences between the two type connections.

This same rule applies to amplifiers,not all amps that have XLR connections on them are balanced amplifiers,many amps have XLR connections as a convience only,once again these connections are merely tied into the standard RCA (Line) connections,running balanced cables from an amplifier with XLR connections that are not truly balanced will yeild no benifit or audible difference.

 

[highfihoney]

There's usually no technical reason for using balanced connections in a home environment. But if it makes you happy...

Balanced cables require three conducters so I'm sure the marketing department has taken liberties with the definition of "balanced".

-Sam

Hi sam, marketing departments have surely taken advantage,what they have done is to confuse buyers into thinking they are buying balanced equipment by cleverly adding XLR connections to non balanced gear.

As for having a technical reason to run balanced cabeling its mostly system dependant, there are huge differences between the two connections if the gear in question is actually balanced or merely has XLR connections for convience, which is mostly the case.

I have both types of gear & on the gear that is not balanced running XLR connections is a waste of time,on the balanced gear differences are clearly audible.

 

[adk highlander]

Thanks highfihoney. Oh well, I guess I fell into the group who thought if it was there it was implemented properly. We can add this to one of the many things I have learned here.

This prepro is the onkyo clone of the new 9.8 integra prepro and from what I have seen of them they are very well built so I never thought this would be the case.

I will also have to look into my MPS-1 and see how the balanced inputs are configured. I know it is in the review somewhere.

 

[Dolby CP-200]

That’s a nice model I haven’t found a pdf file users manual to read though.

http://www.gspr.com/onkyopro/prsc8555p.html

http://www.gspr.com/onkyopro/_okp_news_fr.html

 

[adk highlander]

The page on the integra site with the link for the manual for the 9.8 is here

http://www.integrahometheater.com/own_manuals.cfm?cat=Separates

The Onkyo Pro site does not have a manual. Someone on the Avs site that has one said it is the same manual.

 

[sjsmithjr]

As for having a technical reason to run balanced cabeling its mostly system dependant, there are huge differences between the two connections if the gear in question is actually balanced or merely has XLR connections for convience, which is mostly the case.

I have both types of gear & on the gear that is not balanced running XLR connections is a waste of time,on the balanced gear differences are clearly audible.

I admit to having spent too many years around balanced gear. As such, I can't pick up the nuances so well anymore, but the black sound stage is really black these days. Sometimes I miss the hiss of Class G/H amps in waiting, but I digress.

Dummy XLR connections? I had no idea that consumer audio had stooped so low.

-Sam

 

[OttoMatic]

Hi there,

I think there may be some confusion as to a "fully balanced" design at the amp or pre-amp level and the concept of balanced signalling in general.

First, a balanced signal does use three connections. One for +, one for - and one for ground. The + connection is the "normal" un-inverted audio signal, and the - is the inverse of that same signal. The concept is that any noise introduced to the cable in general, will affect both the + signal as well as the - signal. One of the signals (probably the -) is then inverted at the other end, and added to the other one (in this case, probably the +). Since both the signal and the noise were negated (inverted) before the summation, the noises will cancel out. The audio signal is then manipulated to whatever it needs to be, without whatever noise was introduced in the cable run.

That's why balanced cables are generally touted as being good for noise suppression in long cable runs.

Second, balanced designs can, in general, be used anywhere.

I think this is where the confusion comes in.

A fully balanced pre-amp is using this concept of inverted signals and noise cancellation throughout all its circuitry. Unlike the more simple, unbalanced design, a fully-balanced device must maintain both the + and the - aspect of the signal in every step of the signal path. This creates complexity in design, power consumption, and construction -- at the very least. Of course, it improves noise rejection, and perhaps other things that I'm forgetting at the moment. This is a rather rare device, and fully balanced designs will generally only be found in rather high end equipment (I don't know of any receiver that's fully balanced, and even many very, very nice pre/pros are not fully balanced). If one is looking for a fully balanced design, he will know it, and will have to seek it out.

Fortunately, these designs are not mutually exclusive. A fully balanced preamp can have unbalanced outputs (and I would bet many do, in addition to their balanced outputs).

Additionally, an internally unbalanced design preamp can still use balanced outputs. Of course, the benefit here is to get noise rejection for the cable run.

The way to do this is to simply invert the output of a "normal" preamp just before the balanced connection. You then have the "-" half of the signal, and the "+" half of the signal is already there. The ground is always present.

And this is what's output at the XLR (or tip-ring-sleeve, for that matter) output of a "normal" unbalanced preamp or amplifier. You get the more simply designed and manufactured unbalanced preamp, with the benefit of noise rejection on the physical connection (the balanced interconnects).

I had a look at the manual for the DTC 9.8 and on page 24 it describes the wiring for the XLR connector. Pin is GND, Pin 2 is Hot (what I've been calling "+") and Pin 3 is Cold (what I've been calling "-").

While I can't say "none", I will say that I have never encountered a preamp that claims to be balanced and is not. It's correct to say that the design may not be fully balanced, but the signalling is. And it's the balanced signalling that is advertised as reducing noise over long runs. No, they are not dummy connectors.

If anyone knows of any preamp or amp that's got balanced connectors (XLR or TRS) that is not using balanced signalling, I'd be very interested to be pointed toward that device.

Hope that helps.

 

[Dolby CP-200]

The page on the integra site with the link for the manual for the 9.8 is here

http://www.integrahometheater.com/own_manuals.cfm?cat=Separates

The Onkyo Pro site does not have a manual. Someone on the Avs site that has one said it is the same manual.

I think I gathered that from the rack mounts on the sides for 19” mounting

 

[highfihoney]

Hi there,

I think there may be some confusion as to a "fully balanced" design at the amp or pre-amp level and the concept of balanced signalling in general.

First, a balanced signal does use three connections. One for +, one for - and one for ground. The + connection is the "normal" un-inverted audio signal, and the - is the inverse of that same signal. The concept is that any noise introduced to the cable in general, will affect both the + signal as well as the - signal. One of the signals (probably the -) is then inverted at the other end, and added to the other one (in this case, probably the +). Since both the signal and the noise were negated (inverted) before the summation, the noises will cancel out. The audio signal is then manipulated to whatever it needs to be, without whatever noise was introduced in the cable run.

That's why balanced cables are generally touted as being good for noise suppression in long cable runs.

Second, balanced designs can, in general, be used anywhere.

I think this is where the confusion comes in.

A fully balanced pre-amp is using this concept of inverted signals and noise cancellation throughout all its circuitry. Unlike the more simple, unbalanced design, a fully-balanced device must maintain both the + and the - aspect of the signal in every step of the signal path. This creates complexity in design, power consumption, and construction -- at the very least. Of course, it improves noise rejection, and perhaps other things that I'm forgetting at the moment. This is a rather rare device, and fully balanced designs will generally only be found in rather high end equipment (I don't know of any receiver that's fully balanced, and even many very, very nice pre/pros are not fully balanced). If one is looking for a fully balanced design, he will know it, and will have to seek it out.

Fortunately, these designs are not mutually exclusive. A fully balanced preamp can have unbalanced outputs (and I would bet many do, in addition to their balanced outputs).

Additionally, an internally unbalanced design preamp can still use balanced outputs. Of course, the benefit here is to get noise rejection for the cable run.

The way to do this is to simply invert the output of a "normal" preamp just before the balanced connection. You then have the "-" half of the signal, and the "+" half of the signal is already there. The ground is always present.

And this is what's output at the XLR (or tip-ring-sleeve, for that matter) output of a "normal" unbalanced preamp or amplifier. You get the more simply designed and manufactured unbalanced preamp, with the benefit of noise rejection on the physical connection (the balanced interconnects).

I had a look at the manual for the DTC 9.8 and on page 24 it describes the wiring for the XLR connector. Pin is GND, Pin 2 is Hot (what I've been calling "+") and Pin 3 is Cold (what I've been calling "-").

While I can't say "none", I will say that I have never encountered a preamp that claims to be balanced and is not. It's correct to say that the design may not be fully balanced, but the signalling is. And it's the balanced signalling that is advertised as reducing noise over long runs. No, they are not dummy connectors.

If anyone knows of any preamp or amp that's got balanced connectors (XLR or TRS) that is not using balanced signalling, I'd be very interested to be pointed toward that device.

Hope that helps.

Hi otto,i forgot about this thread till today

Pop the hood on a few different preamps that are not balanced units & look at how the XLR connections are ran to the unit,on most unbalaced units they are tied directly into the same green board as the RCA inputs,on balanced units they are not tied into the same green board & connect to the amplifier seperately.

I may be missing something here but on my unbalanced units this is the way the XLR's are incorporated,also ,to me it would seem that if the XLR' are sharing the same connection point as the RCA connections then any benifit of running XLR stops at the back of the amplifier.

If im off base here please correct me.

 

[OttoMatic]

Pop the hood on a few different preamps that are not balanced units

By that do you mean a preamp that's not fully balanced, but that does have balanced XLR outputs?

look at how the XLR connections are ran to the unit,on most unbalaced units they are tied directly into the same green board as the RCA inputs

Well, just because the XLR connector interfaces with the same PCBA as the RCA connectors doesn't mean that it's not balanced. We'd have to consider how the three pins of the XLR jack are connected. There are three connectors: +, -, ground (aka HOT, COLD and GROUND). Are you thinking that they just tied COLD to GROUND?

on balanced units they are not tied into the same green board & connect to the amplifier seperately.

I could see that a fully balanced design would have different connection points for the balanced connectors (XLR) when compared to the single-ended connectors (RCA).

I may be missing something here but on my unbalanced units this is the way the XLR's are incorporated,also ,to me it would seem that if the XLR' are sharing the same connection point as the RCA connections then any benifit of running XLR stops at the back of the amplifier.

We'll I'd really expect the HOT lead of the XLR connector to be identical to that of the HOT of the RCA connector. I would expect them to tie it to the same output as the RCA, or very closely, perhaps through some type of buffer. They then have to implement the inverse of the HOT (which becomes the COLD) for the XLR connector. That's not hard to do, and will almost certainly be done on the same PCBA, very near the output stage.

It's hard to tell what a circuit is doing just from looking at the board and the jacks. The best way to ensure that a device is indeed using balanced signalling is to measure the pins at the output of the preamp. There should be signal present at pins 2 and 3, and pin 1 should be ground.

If you have a preamp that measures no signal at pin 3 (COLD) while there is signal at pin 2 (HOT), the you are not using balanced signalling, even though the connector affords three conductors. That's pretty much the way it would have to be set up to cause it to be single-ended. Anything on pin 3 other than the inverse of pin 2 will drastically muck up the signal, and therefore the final audio.

If you run into this condition, and the manufacturer has stated that it's a "balanced output," then they are just flat-out lying. If you know of one that definitely doesn't output on pins 2 and 3, let me know, I'd be interested to look it up.

As far as I can tell, the Integra link provided above describes a balanced signalling scheme. Just because the specs don't call out info for balanced and single-ended connections doesn't mean it's not balanced. I just looked at my old Outlaw 990 manual and it doesn't state anything about the balanced or XLR connections in the specs. The manual for the Cary Cinema 11 somewhat sloppily calls out some differences for the XLR connectors, though. I know both of these preamps are single-ended designs (i.e., they are not fully balanced throuhgout) using balanced outputs, so it's rather up to the manufacturer how well they specify the information for their preamps in their specs.

If im off base here please correct me.

Well, I'm not saying it's impossible that anyone's ever done this, but I just think it'd be kind of weird. If a company is stating that they have balanced inputs or outputs, then the three wire XLR cable had better have two signals (one the inverse of the other) and a ground. If you know of any preamp that's not doing this, but that has XLR connectors, please let me know.

Have a good day!