Balanced XLR vs RCA's - what's the deal?

[alpina]

hi guys,

finally geting around to the wiring end and am wondering what the deal is between balanced XLR vs RCA? What makes one better than the other and what are the real world sonic differences between the two?

cheers,

julie

[Audiophiliac]

Basically a balanced system uses a 180 degree out of phase signal in addition to the signal in hopes that the noise will be cancelled out. It works. You see it a lot in pro audio and for really long runs.

You really have to try it in your system to see if you notice any benefits. But it does make a sonic difference to some people in some instances.

We had the Krell system set up when we first got Wilson Audio in. And when John came down to help set up our Watt/Puppies, we listened to the Krell in single ended, balanced, and CAST. And while I wasnt in the room when they compared the RCA to the CAST, I was there when we decided that the Balanced connection somehow sounded "better" than the CAST.

The short answer is try it for yourself and decide with your ears.

[alebonau]

theres an interesting paper on the arcam site re this question that might help answer it.

http://www.arcam.co.uk/downloads/finding%20the%20balance.pdf

its basically helps with long runs particualry in pro setups. Though for the typically very short runs of domestic gear it may make little or no difference. As audiophiliac suggests pribably best to borrow some cables to check out if it makes any difference at all in your setup.

[Lex]

it should also be noted that true balanced differs from just XLR. XLR found on average priced gear may not truly be balanced. Internal, XLR can still be unbalanaced. Levinson, Krell, other highest end gear likely assures true balanced. mid end gear may not.

[alpina]

it should also be noted that true balanced differs from just XLR. XLR found on average priced gear may not truly be balanced. Internal, XLR can still be unbalanaced. Levinson, Krell, other highest end gear likely assures true balanced. mid end gear may not.

Would this apply to Bryston gear also?

Julie

[junior77blue]

There may or may not be a difference between XLR vs. RCA.

I did notice with my Adcom 'GOLD" series gear, there are different spedifications depending on which output/input you use.

Not to mention the physical connection between an RCA and XLR, where the XLR is far more superior to work with, and know there is a secure connection without ripping out ur female terminals, i.e. it's not a friction fit, it's a mechanical locking mechanism.

[JonMarsh]

There are varying levels of "balanced"- Bryston is fairly good active balanced.

OTOH, high grade transformer balanced takes it to an even higher level of noise isolation, but is found only on very high end components, due to cost- wholesale price of each transformer may be $100-200 (go look at Jensen Transformers online, what I use in my homemade gear).

[ToddAnisman]

There's one other thing that I would like to point out....

The operating level of a true balanced system is much higher than a RCA/Unbalanced system. So the rule of thumb would be, Don't mix and match. For example, don't plug a Balanced +4dBu signal into the front end of an amp that is designed for UNbalanced -10dBv, unless you use the proper Level matching hardware....It's not enough to just turn it down. you're gonna see lot's o' noise or distortion.

Here's the one rub I have against Balanced.....poorly designed electronic balancing, impedance balancing etc. can have an adverse afffect on your signal moreso than an unbalanced i/o can have. In Studios, Balanced signals Rule, but our components are much more hardy (and expensive) than you would find in a Home theater setup (not knocking, just pointing out diff apps...). I have heard some absolutely horrible pieces of gear that sound OK when used UNbalanced.

So iguess I'm saying that don't get balanced just for the sake of it, but if you do, be prepared for what it entails- more expense, more thought. However, you do get a ton more flexibility, Ability to troubleshoot noisy installs, etc.

-Todd A.

[Victor]

Would this apply to Bryston gear also?

Julie

None of Bryston products employ a truly differential or balanced signal processing. Bryston converts the signal to single-ended type at the input, does the processing, i.e. volume control, gain, etc., and then converts back to the differential or balanced type. Nothing wrong with that.

Bryston uses a discrete transistor based op-amp circuit as a differential amplifier to do the differential to single-ended conversion. If you look at the circuit published on their website you'll see that even with resistors matched the common-mode rejection is still very poor, so I am not sure how much good does this approach really do for Bryston. An integrated driver would have been better, but it is contrary to Bryston philosophy.

Victor