Balanced vs unbalanced interconnects

[cfrahme52]

Although the Rotel RC1090 and RB1080 allow for either balanced or unbalanced connections, I believe I read somewhere on this forum that with Rotel gear there is nothing to be gained going the XLR route.
Is this so? Why?
I've been toying with the idea of purchasing a balanced pair of Nordost Solar Winds, but don't want to spend the money if there will be no advantages.
I'd apprecitate hearing from anyone with the above combo and their experiences with RCA vs XLR interconnects.
Thanks.
Charlie

[Kevin D]

Balanced cables mainly see there improvements over long runs, hence why most comercial applications use them. While the 1080 gives you the option to feed it a balanced signal, the amp itself is not designed for it. The balanced inputs are immediately converted and fed into the same circuit the unbalanced are.

If your CD player has balanced outputs, you might see some improvement be running it into the balanced input on the RC1090 however.

Kevin D.

[snowball]

is the rb-1090 is designed for XLR then?
oh and what exactly are the advantages of XLR ??

[mjb]

The rb-1090 has XLR inputs.
Balanced systems have the advantage of a third conductor which contains the audio signal inverted. Any interferance will be equally induced in both signal leads, and can thus be cancelled out. A coax relies soley on its screen to prevent interference being induced.

[greggz]

I'm not familiar with the RC-1090, but the RB-1080, RB-1090, and RB-1095 are considered "quasi-balanced"

In order for an amp to be truly balanced, it must be balanced thru the entire circuit. Rotels are not balanced internally. For interoperability purposes with preamps that only have balanced/XLR connections they offer XLR connections on their higher model amps.

This is why there is no advantage to going with balanced interconnects on the Rotel.

[snowball]

I'm not familiar with the RC-1090, but the RB-1080, RB-1090, and RB-1095 are considered "quasi-balanced"

In order for an amp to be truly balanced, it must be balanced thru the entire circuit. Rotels are not balanced internally. For interoperability purposes with preamps that only have balanced/XLR connections they offer XLR connections on their higher model amps.

This is why there is no advantage to going with balanced interconnects on the Rotel.

i thought those where the high ends of rotel!

so to "really" profit from XLR cables the amp(or the pre?) must be balanced internally.
What are the advantages/disadvantages of using this sort of amps and cables over normal connections?
Is it more for studio use?
some general help here will be appreciated,since i am going to buy my first system shortly and rotels will be the amps probably!

i have to admit that am quite a knoob on the technicals,i mean i can hook up amps and generally good with my hands and electronic devices but i havent done my homework yet on the high end audio!
Which i will do yesterday!

[aud19]

Unless all of your connected gear is of a truly balanced design and you have long and/or noisy runs, XLR is a waste of money IMO.

[r100gs]

Unless all of your connected gear is of a truly balanced design and you have long and/or noisy runs, XLR is a waste of money IMO.

Can someone explain to me what "truly balanced design" means? Are there bogus XLR connections out there?

[Glen B]

Can someone explain to me what "truly balanced design" means? Are there bogus XLR connections out there?

In a truly balanced design, each channel consists of what is essentially two separate amplifiers in one. One side amplifies the positive half of the audio signal and the other side amplifies the negative half of the audio signal. The two halves of the audio signal are kept completely separate throughout the amplification process until they are combined at the output.

With quasi-balancing, the "balancing"/"unbalancing" is accomplished electronically. The audio signal is converted from/to a single-ended signal electronically and amplified through a single set of amplification stages.

[Shawn Parr]

Hello all, I've been lurking here for a while doing really early research for an upgrade. I've seen some stuff here that isn't quite right so I thought I would register and add my input.

I have been a professional sound engineer and sound designer for the last 12 years, so one would think I have an idea what I'm talking about.

Most professional equipment is not balanced completely through the entire circuit path. Take this example from a Soundcraft mixer:



There is a symbol in there that looks like:



That is a differential amplifier. The + and - symbols indicate the hot and cold legs of a balanced line, respectively. Most professional (and I would imagine Hi-Fi) equipment has differential amplifiers immediately after the inputs, and any circuitry inside the device (mixer, amplifier, etc) are unbalanced. This is considered "truly balanced."

There is a system referred to as "impedance balanced" which is much the same, except rather than sending the signal inverted on the cold leg, you do not send any signal. Then the differential amplifier on the receiving end takes the cold leg and polarity inverts it like normal and adds it to the hot leg, which removes noise, but does not get the +6dB increase in signal strength that the fully balanced connection gets. You still get pretty darn good CMR though.

Now there is some gear in the pro world that is balanced all the way through. The first that pops into my mind is the Amek BCIII mixer. This was a very expensive mixer though, 24 channels costing about $80,000 IIR. It also happened to sound great as well, but it is highly questionable whether it was the balancing that made it sound so good, most Amek mixers sound really good, and unfortunately all the models have their own characteristics so a side by side comparison is not really possible.

Now maybe in the Hi-Fi world things are different, but I would be surprised to see any balanced equipment that didn't use unbalanced signal internally.

For those that are not aware, the rule of thumb used in classes is that 20' or less runs are usually okay with unbalanced lines if there are not any major considerations, anything over 20' balanced is desired for its noise rejection.

One should also consider the fact that any components added to the signal chain add character, good or bad. As such many purist engineers shy away from balanced connections when they feel they are unnecessary as to avoid the coloration the differential amplifiers add. Mind you it is pretty rare to run into one of these guys. Of course my monitoring system is unbalanced, but that has more to do with the fact that my Crown DC300A amplifier is unbalanced.

In the end one should listen to determine what sound you prefer (as always), however balanced is not necessarily better due to the circuitry involved, and with most hifi systems cable length is not an issue for noise so you most likely save a lot of money staying in the unbalanced realm.

[RebelMan]

Unless all of your connected gear is of a truly balanced design and you have long and/or noisy runs, XLR is a waste of money IMO.

Jason have you compared balanced and unbalanced connections with fully balanced equipment (from source to pre to amp)? Some manufacturers insist that balanced connections be used with their equipment, regardless of run length, for the best results. Unfortunately, the opportunity hasn't presented itself to me. Your experience in this matter would be helpful.

[aud19]

Honestly not for quite a few years so forgive me if the memory's a little hazy

What I do remember was that on the short runs the sound was different though not necessarily better or worse. My guess would be that that without having to reject any noise etc in those short runs that any difference I was hearing was likely due to circuitry etc and possibly the signal increase Shawn mentioned above (great technical info BTW :T )

So as I said, especially with equipment that's not really balanced, it's not worth the added trouble and expense in 99% of cases unless you're having trouble with long and noisy runs IMO.

[r100gs]

Honestly not for quite a few years so forgive me if the memory's a little hazy

What I do remember was that on the short runs the sound was different though not necessarily better or worse. My guess would be that that without having to reject any noise etc in those short runs that any difference I was hearing was likely due to circuitry etc and possibly the signal increase Shawn mentioned above (great technical info BTW :T )

So as I said, especially with equipment that's not really balanced, it's not worth the added trouble and expense in 99% of cases unless you're having trouble with long and noisy runs IMO.

I'm not sure my equipment is truly balanced. I suspect it is not. I've always felt the xlr's gave no noticable improvement. They look cool anyway.