balance vs. unbalanced I/Cs

leftwinger57

This is a carry over from ScomRacer's post of getting an Audio Research tubed pre. Not to single out AR, most high to very high end gear gives the choice of either i/c. Now I've seen the balanced i/c with it's locking multi pin vs. the unbalanced RCA type way more common i/c. Knowing how expensive the AR gear was and if 1 was going for that species of top shelf gear does the balanced i/c make that much of a difference. In simple laymans' terms what is so different (besides the obvious connectors) and knowing my ears are far from golden, maybe bauxite if that can these 2 totally different connectors be explained for doing the same thing. From what I have seen most pro gear like mics, soundboard, and recording applications use balanced i/c.

hochpt21

Lew, please don't get mad at me but just hit enter twice every two sentences.

You have a lot of valuable information but it's so hard to read your posts sometimes.

As far as your question, I think balanced typically makes a difference if the components are truly balanced along the whole chain.

EndersShadow

hochpt21 wrote: »

As far as your question, I think balanced typically makes a difference if the components are truly balanced along the whole chain.

^This. Additionally if you have TRUE balanced the ought the whole system the noise floor is lower and you get a 3db increase in sound.

That said lots of gear is quasi balanced negating those effects.

My B&K amp has both inputs but is only quasi balanced. The Marantz Pre I want (AV7702) is also only quasi balanced...

In my 2 channel my DacMagic has XLR and the B&K Reference 50 has XLR in and out but again quasi balanced..

So pointless.. Doesn't mean I'm not debating it anyway lol....

leftwinger57

No excuse, most here know I'm both technically and grammatically challenged with this machine.
That being said I think things have gotten better or else I'd really be hearing it from all comers by this time.
Now even if ALL Connectors were balanced, what does that do to make the sound that much better ? 3db in sound and with that and using top shelf gear means, it's that much better in efficiency and sound reproduction ?
Again w/ Dan's reply having 2 to 4 quasi i/c throws the proverbial monkey wrench into the mix unless one goes for truly state 'o art type gear.

More is needed to justify the expense, it's made for a reason and in 2 separate types and not for variety.----Lew

Glen B

I think your question has been answered. If all your gear is true differential balanced from input to output, then you may find some audible benefit from using the balanced connections. Ditto if you have long cable connections that are susceptible to noise pickup. You will benefit from the common-mode noise reduction of balanced connections, regardless whether the gear is internally balanced or single-ended with balanced converters. Otherwise, just use RCAs.

One other thing, balanced connections or the lack of them is not necessarily a measure of state of the art audio. There are many fine top-shelf designs that are single ended. Let your ears be the judge.

Speedskater

a] It's not about the cables, it's about the entire interconnect system! The cables are only 1/3 of the system.

b] What the heck is a quasi balanced input ? Or for that matter a quasi balanced output ? It only takes a couple of resistors & capacitors to make a true balanced output, so what's the problem?

c] Balanced interconnect systems reduce noise & interference significantly, but with short interconnects it may not matter.

vc69

A simple google search turns up the answers that you seek.

Speedskater

OK, so a quasi balanced output is really an impedance-balanced output. There is absolutely nothing wrong with that. As to what a quasi balanced input is, I still have no clue.

The big problem in the hi-fi world with balanced interconnect systems is incorrectly wired XLR chassis connectors. It's been 20 years since the connector problem was pointed out and some hi-fi manufactures are still doing it incorrectly.

BlueFox

While I like the balanced cables due to the more secure connector, a problem I see further down the road is if I get a new pre, or amps, I need to make sure they have balanced inputs. Otherwise, I will need to buy new cables.

msg

I notice a bit of a difference in quality and output using XLR cables. even cheap ones.
(is this output bump due to reduction in noise? or at least partly?)

first noticed when I first got started in this about a year and a half ago, working with an older B&K EX-442 and MC-101 preamp I found locally. all my cables were cheap ones, and I noticed with the XLR's from the pre to the amp that it sounded a little louder at the same volume. it also seemed a touch smoother and fuller. at the time I was trying (futilely) to make some RTi10's work for music, so my bloodied ears picked up any improvement. In fact, I didn't notice the difference the XLR's made until I tried RCA IC's while swapping gear around, and noticed things not sounding quite as good as before. the difference wasn't huge, but significant enough to not ignore. maybe this wouldn't have been apparent at all had I been using all good cables, don't know. I'm only just now beginning to explore better quality cables, but if I have the option for XLR - for 2ch, at least - I'll do it.

vc69

msg wrote: »

I notice a bit of a difference in quality and output using XLR cables. even cheap ones. <snip>
all my cables were cheap ones, and I noticed with the XLR's from the pre to the amp that it sounded a little louder at the same volume. it also seemed a touch smoother and fuller.

Balanced provides +4 db in gain. That is most likely the difference you are hearing. I have also found that balanced connections are not "as" sensitive to various cable designs as single-ended connections seem to be. That said, my buddy swears by balanced, I swear by single-ended. I think there are environments that are far better suited for single-ended than others. Long cable runs, environmental noise (RF, AC inductance noise, etc.) are situations where balanced is far superior.
It should also be noted that a fully balanced circuit is not a common thing in my experience. Particularly where source pieces are concerned. It's often a marketing gimmick, but certainly not always.

CoolJazz

Let me be the one to disagree with the "whole system has to be balanced to make a difference" stick in the mud.

First on the differential versus single ended, and I believe this greatly underrated, the balanced interconnect offers a way to separate ground currents between the devices instead of tying them together. Current loops is why in digital they've found such gain in multiple power supplies...not sharing unnecessary grounding between stages. We have separate "boxes" but we still can gain from not tying them together with unbalanced connections.

Second, the typical balanced in first stage and out last stage circuits are largely a lot the same as the unbalanced. Here is a pretty typical simplified drawing of the balanced in...



This stage is where the common mode rejection comes from. If you didn't have this stage, then how and where do you get any CMMR? If your "fully balanced" this still has to take place to get the gain the topology is to bring. The balanced version is similar, but different. Usually just two stages instead of one side by side setup for the CMRR but opposite phase for that balanced output into the rest of the device.

So when you have the "fully balance" as people talk about, then you normally have this very input stage PLUS you have to have a VERY tightly matched components making each half the signal be exactly identical. Every tiny bit of deviation from finely matching adds a distortion that internally unbalanced does not have. I've posted, probably several times, the Stereophile article of years ago that addressed this issue and why while balanced internal circuits can and does have advantages, it is costly to implement and can have pitfalls.

Gains beyond noise are there with balanced connection. Noise rejection and equipment circuit current loops can be avoided. And whether internal circuits are balanced or unbalanced is really an unrelated issue.

The quasi-balanced term is often applied when the output doesn't have both halves driven and instead either using a ground connection or a resistor floated potential as the low side of the balanced feed, letting the input CMMR yield some noise rejection yet less than active balanced could give you. This also means you have 6db less signal to work with. So wiring from unbalanced out to balanced in with proper wiring will either give you close to or the same thing depending on exactly how they derived that quasi-balance. To truly get the maximum out of the balanced connection interface the high and low needs to not just have the same signal in opposing phase but also have the same impedance characteristic. The quasi-balance doesn't achieve the same numbers but does still have some noise rejection characteristics.

Lots of details and issues with both the interconnect issue and also the balanced internal topology, but to simplify it down to "all balanced all the way or no gain" is to me just plain wrong and it gets repeated over and over is still never true. Just my opinion...

CJ

btown1985

Man, there are some pretty smart guys around here!

btown1985

My system is not fully balanced but the exchange of unbalanced to balanced from my source to preamp provided the + 3 or 4 db in gain that has been mentioned.

EndersShadow

Mark thank you for that information. I may pick your brain later about this.

SCompRacer

One of the main reasons I went balanced a couple years ago was due to my diy DAC. Output stage is fully balanced discrete output, where SE out has op amps. Balanced out sounds better so I went with a balanced pre amp.