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Audiophile hi-fi market and balanced connections
Brand
post Aug 26 2012, 14:38
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Even many cheap-ish $100 sound cards have balanced connections.
Yet, for a $4,295 "audiophile" amp, it's somehow normal to have unbalanced analog only. (But hey, you get a "Digital Filter Slope" switch..)

Am I missing something or is this just regular audiofoolery at work?

I was doing some RMAA tests and the cables were very susceptible to outside interference. Place them next to some other (power) cables and you easily see 20dB of extra noise in the measurements.
Sure, it's not really a problem with short cables that you keep away from interference, but for premium/audiophile equipment I'd still expect balanced connections to be the standard by now.

This post has been edited by Brand: Aug 26 2012, 14:39
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smok3
post Aug 26 2012, 18:00
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QUOTE (Brand @ Aug 26 2012, 15:38) *
Even many cheap-ish $100 sound cards have balanced connections.
Yet, for a $4,295 "audiophile" amp, it's somehow normal to have unbalanced analog only. (But hey, you get a "Digital Filter Slope" switch..)

Really? i guess iam out of touch this days, but i thought balanced is pretty much pro-audio stuff.
(But whats 4295 for such a cute front-plate, you know you want it...)

QUOTE (Brand @ Aug 26 2012, 15:38) *
I was doing some RMAA tests and the cables were very susceptible to outside interference. Place them next to some other (power) cables and you easily see 20dB of extra noise in the measurements.
Sure, it's not really a problem with short cables that you keep away from interference, but for premium/audiophile equipment I'd still expect balanced connections to be the standard by now.

Obviously you would want to use some digital connection.

(personally my only home hi-fi this days is osx box with unbalanced analog connections to old marantz amp, very danceable, dustlifting device)

This post has been edited by smok3: Aug 26 2012, 18:07


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Brand
post Aug 26 2012, 19:29
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Well, to be fair, the average $4k hi-fi amp might include balanced inputs (I'm not much into hi-fi these days). I had a quick glance at the Marantz and Yamaha offerings and the most expensive models do have that.

But I don't see any technical or cost-associated reason for this to be restricted to premium priced models. Balanced I/O takes a bit more space, but nothing an average size hi-fi amp couldn't handle.
In "pro audio" you get it with $60 soundcards.
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dumdidum
post Aug 27 2012, 09:23
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QUOTE (Brand @ Aug 26 2012, 15:38) *
I was doing some RMAA tests and the cables were very susceptible to outside interference. Place them next to some other (power) cables and you easily see 20dB of extra noise in the measurements.

i haven't done any tests myself but lots of anecdotal evidence says otherwise. better noise rejection of balanced doesn't seem to make a difference for your typical hifi usage scenario.

QUOTE (Brand @ Aug 26 2012, 20:29) *
But I don't see any technical or cost-associated reason for this to be restricted to premium priced models.

i can think of two:

(i) balanced cables do not sound better, they just reject noise better. once again, lots of anecdotal evidence suggests noise rejection by the cables rarely becomes an issue in consumer applications. it's different in pro-audio applications where you may have to run very long cables, you may have to run cables by sources of noise (e.g., fog machines, strobes and other lighting, some other PA equipment, appliances, etc.), you have long chains (where the chance of ground loops is higher). it's not cost-effective to included balanced connectors if they're not needed.

(ii) balanced TRS and balanced XLR are quite uncommon in consumer audio. what good does a consumer amp with balanced inputs if consumer don't have other devices with balanced outputs? inclusion of features that go unused doesn't make sense (well, unless we're serving "check-box" customers that pay a premium for incredibly long feature lists).

This post has been edited by dumdidum: Aug 27 2012, 09:29
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Brand
post Aug 27 2012, 15:18
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QUOTE (dumdidum @ Aug 27 2012, 10:23) *
(i) balanced cables do not sound better, they just reject noise better. once again, lots of anecdotal evidence suggests noise rejection by the cables rarely becomes an issue in consumer applications. it's different in pro-audio applications where you may have to run very long cables, you may have to run cables by sources of noise (e.g., fog machines, strobes and other lighting, some other PA equipment, appliances, etc.), you have long chains (where the chance of ground loops is higher). it's not cost-effective to included balanced connectors if they're not needed.

Here are my measurements: LEFT with the random placing of the cable, for the RIGHT one I placed the cable carefully, to avoid some power cords (which you could get in a typical hi-fi setup, no strobes etc.).


Maybe the noise is audible, maybe not.
But I believe a balanced connection would handle noise rejection better.
Unfortunately I don't have a soundcard with balanced I/O here to test it. If someone does, some tests would be welcome.


QUOTE (dumdidum @ Aug 27 2012, 10:23) *
(ii) balanced TRS and balanced XLR are quite uncommon in consumer audio. what good does a consumer amp with balanced inputs if consumer don't have other devices with balanced outputs? inclusion of features that go unused doesn't make sense (well, unless we're serving "check-box" customers that pay a premium for incredibly long feature lists).

Of course, you need the whole chain to be balanced, if not it doesn't make sense. This not being common in hi-fi is exactly what I'm complaining about. It's a chicken and egg situation.

My point is not that balanced connections would necessarily offer audible improvements (although I think they would in some cases), it's that the audiophile hi-fi market priorities are twisted.
If you're into audiophile stuff and you care about little details, balanced connections is one of the first things you should use (assuming you're using analog interconnects).
More important than stuff like expensive speaker wires and 32bit 192khz DACs and whatnot.
And the extra cost of balanced I/O doesn't seem to be a good excuse either, if not you wouldn't have balanced I/O in cheap gear.
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2Bdecided
post Aug 28 2012, 11:13
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Remembering for a second that audiophile equipment isn't always about how it actually sounds, or actually measures, but more about perception and myth, there's another factor: If the circuits in the devices being connected don't already use some kind of balanced signal topology, then adding a balanced output means adding extra electrical components in the signal path. In the audiophile mind, extra components = bad. They'd rather route their analogue audio cables more carefully (standing them on graphite blocks 10cm above the ground to avoid interference) than use a connection that natively reduces interference but introduces "unnecessary" electrical components. Plus there are far more tweako audiophile cables available in unbalanced than balanced form.

Some audiophile equipment offers both though.


IMO there is something to be said for good simple circuit design, and the simple (though sometimes naively applied truth) that adding more components in unthinking ways can simply add to noise. But beware of audiophile circuits that are simple because they reject all the improvements in circuit design of the last 70 years - these can have audible problems. Plus many modern ICs, used correctly, are phenomenal.


As others have said, most home audio doesn't need balanced audio. Where there are problems, it can solve some (e.g. interference), but not others (e.g. ground loops).

Cheers,
David.
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Arnold B. Kruege...
post Aug 28 2012, 12:51
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QUOTE (Brand @ Aug 26 2012, 09:38) *
Even many cheap-ish $100 sound cards have balanced connections.
Yet, for a $4,295 "audiophile" amp, it's somehow normal to have unbalanced analog only. (But hey, you get a "Digital Filter Slope" switch..)

Am I missing something or is this just regular audiofoolery at work?


The latter.

QUOTE
I was doing some RMAA tests and the cables were very susceptible to outside interference. Place them next to some other (power) cables and you easily see 20dB of extra noise in the measurements.
Sure, it's not really a problem with short cables that you keep away from interference, but for premium/audiophile equipment I'd still expect balanced connections to be the standard by now.


In the whacky world of audio's high end it almost seems like people want to make big steps backward in the interest of creating unnecessary audible differences. Take for example the SET amplifier which uses technology that was rarely if ever actually used back in the days when tubes were all we had. Better technology known as the push-pull power amplifier with inverse feedback was the rule for quality amplifiers. The most common SETs I saw back in the day were the audio sections of cheap receivers. Even TV sets, if they had pretensions to quality, used push-pull output stages.

Is hum a bad thing? One audio company proudly sold a CD with "Analog Dither" that included some 120 Hz hum. Just what you need to add to your "too sterile sounding" recordings. :-(

The practical reason that balanced I/O is the professional standard is that it is more foolproof and works more stably in complex systems. For example, the media booth at my church has close to 100 wall outlets, each with some kind of doo-dad plugged into it. They are all connected either directly or indirectly to the digital audio console. The whole system generally runs free of audible hum.

The biggest problem with hum comes from the electric guitars, and guess what, the standard there is an unbalanced connection. We finesse that with the standard tool - a "Direct Box" which is basically an isolation transformer that isolates the guitar's pickup coil from system ground (and vice versa).
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Arnold B. Kruege...
post Aug 28 2012, 13:04
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QUOTE (Brand @ Aug 27 2012, 10:18) *
QUOTE (dumdidum @ Aug 27 2012, 10:23) *
(i) balanced cables do not sound better, they just reject noise better. once again, lots of anecdotal evidence suggests noise rejection by the cables rarely becomes an issue in consumer applications. it's different in pro-audio applications where you may have to run very long cables, you may have to run cables by sources of noise (e.g., fog machines, strobes and other lighting, some other PA equipment, appliances, etc.), you have long chains (where the chance of ground loops is higher). it's not cost-effective to included balanced connectors if they're not needed.

Here are my measurements: LEFT with the random placing of the cable, for the RIGHT one I placed the cable carefully, to avoid some power cords (which you could get in a typical hi-fi setup, no strobes etc.).


Maybe the noise is audible, maybe not.
But I believe a balanced connection would handle noise rejection better.
Unfortunately I don't have a soundcard with balanced I/O here to test it. If someone does, some tests would be welcome.


Back in the day when I was running the PCAVTech web site, I rather quickly rediscovered the benefits of using audio interfaces with balanced inputs for making all of my measurements. I had been here before with analog measurements in the 1980s. I did much of my work with an audio interface called the CardDeluxe that had balanced I/O. The way I interfaced it to unbalanced sources was is described in this document:



Rane Note 110 - a classic

Figure 4, circuit 18.

QUOTE
QUOTE (dumdidum @ Aug 27 2012, 10:23) *
(ii) balanced TRS and balanced XLR are quite uncommon in consumer audio. what good does a consumer amp with balanced inputs if consumer don't have other devices with balanced outputs? inclusion of features that go unused doesn't make sense (well, unless we're serving "check-box" customers that pay a premium for incredibly long feature lists).

Of course, you need the whole chain to be balanced, if not it doesn't make sense.


False.

There's no problem with unbalanced circuitry as long as it is well-designed, inside the same box, and uses the same power supply. Most audio gear that is balanced at all is only balanced at the inputs and outputs.

There's no problem with unbalanced circuitry as long as you keep the levels up and avoid grounding problems and other sources of hum pickup. Of course that makes systems with unbalanced connections fiddley, but in a small system that is not taken down and set up a lot, it is usually a very manageable situation.

The long term solution to hum in interconnections in consumer audio systems is to go digital. Hence HDMI. BTW, the physical interface that HDMI is based on is balanced I/O. Optical I/O finesses the problem by avoiding the low end of the EM spectrum totally, and SP/DIF is supposed to be implemented with transformers that avoid many potential grounding problems.
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Brand
post Aug 28 2012, 16:30
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With the "whole chain" I actually meant just that both the output (say, of a CD player) and the input (amp) need to be balanced for the balanced aspect to work. Perhaps redundant, but I wanted to point that out.
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Arnold B. Kruege...
post Aug 29 2012, 14:42
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QUOTE (Brand @ Aug 28 2012, 11:30) *
With the "whole chain" I actually meant just that both the output (say, of a CD player) and the input (amp) need to be balanced for the balanced aspect to work. Perhaps redundant, but I wanted to point that out.


I agree that if you want the best reasonably possible dynamic range easily via analog, you use balanced connections in audio systems.

The classic simple CD player -> receiver system works well enough that way as a rule.

Thing is, as soon as you add much more complexity, even just a grounded FM antenna, to that setup things can easily go west.
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RonaldDumsfeld
post Aug 29 2012, 17:59
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We can already buy USB microphones, turntables and digital powered monitors so presumably the issue will solve itself in a few years when all signal manipulation and transfer is carried out digitally and all transducers have clean but inexpensive built in ADC/DAC chips?
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