[Gamerphile]

Right now I'm in the process of gathering the last information and such for studie in spatial sound like binaural recordings vs HRTF algorithms. I'm trying to get fonding for the HeadRoom Balanced Desktop Amp be course among other things more important it also is balanced all the way as far as I'm told. I'm going to studie this topic here atleast in relations balanced VS unbalanced influence on sparatial sound information.

So if you wait like say... a year - you can, hopefully, get the scientific answer

 

[krmathis]

Quote:

Originally Posted by Audio-Omega /img/forum/go_quote.gif I don't remember if this has been posted, what are the disadvantages of balanced with regard to sound quality ?

I can't think of any.
As long as the channels in the amplifier are properly matched.

 

[22906]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif That's pretty much how I see it, too. But I wanted to point out that you can get much the same performance by bridging two amps, or even having an active ground plane like in the M^3 or a 3 channel Beta22. Don't much agree with the source first mantra, either. Since dollars (for whatever reason) figure heavily into whether a source is quality or not, I'll put out that my vinyl setup retails somewhere north of $12k. That, fed through the Zana and into the crap Sony headphones (used as a dummy load for amp building) sounds terrible. A RS-1 jacked into an iPod with lossy files sounds surprisingly good. Even five figures of equipment won't make a bad transducer sound good. The other side of the coin is the amp. A transducer does nothing without one. So if you have a good transducer, you need to power it fully. What good is a perfect signal fed into something that mangles it before getting to the transducer? You lose all the benefit of the source at that point. The other fallacy is that there's a huge difference between sources. There is some, for sure, but even cheap CD players put out good numbers for distortion and other important specs. There was more variation 30 years ago with sources, but even a $50 CD player is pretty accurate today. The other side to this is the advance of digital technology. A $6k CD player from 6-7 years ago isn't worth much today and can probably be bested by a $1k player from 2008. That trend will continue.

The idea of source first is that you already have a decent enough amp and transducer to discern the difference between sources. It is more useful to look at the source first when upgrading, assuming you already have a listenable system to build upon.

Nobody is saying a good source can magically improve the performance of other components. It's just that you can reach a point of diminishing returns with amp and headphone upgrades without investing as much time (listening experience, auditioning, testing) and money (the most expensive sources are not always the best) as you would have to to obtain a source good enough that it wouldn't be the bottleneck in your system.

This is especially true with digital sources, because when digital technology advances, it is usually in terms of smaller size, lower power consumption, and cheaper costs at the expense of outright sound quality.

 

[Maxvla]

These two amps aren't exactly comparable, but after about 15 hours on my new balanced MKVI I can clearly state that it feels like the signal is being pushed down my HD600's throat, whereas my SE MKIII just seems to be casually advancing the signal. I can really feel the power of this balanced amp and even with the demanding HD600 I am only beginning to tap the power of this amp. Comfortable listening volume with rock music doesn't pass 20% on the dial. Classical I can handle up to 25-30% sometimes. My MKIII I was at about 50% for normal listening.

I've heard it stated on this forum that if you surpass 50% volume you need to upgrade your amp. I did and am now enjoying the next tier of power.

For the comparatively small investment of $699+ship of this MKVI I think there is no reason not to try balanced. People throw around suggestions of Beta22 and the like which would run nearly $1000 in parts or well over $2000 to have one crafted for you.

 

[mulveling]

Quote:

Originally Posted by Maxvla /img/forum/go_quote.gif I've heard it stated on this forum that if you surpass 50% volume you need to upgrade your amp.

That...sounds like very poor advice. If by 50% of volume they meant "3db down from max rated output", then yes you could probably use a new amp with more power or a balanced version of the same amp (which will have likely supply much more power). However, you will not enjoy this for long as you will soon go deaf - most headphone amps have the power capacity for INSANE volume levels with modern headphones.

If by 50% they mean halfway on the volume dial, then this is a meaningless statement. The SPL/power output at any given dial position will depend on recording level, source output level, the amp's gain, plus the headphone's impedance & sensitivity, NOT the amp's power output capacity. For all these variables, you can't tell how much power reserve an amp has at any given dial position. It could be cruising with 20db+ headroom or it could be at/near clipping - not an indicator of anything.

To me, the best balanced and the best single-ended amps/systems I've heard have BOTH produced a magical sound quality. I have yet to be convinced that going balanced is worth the cost of paying for double the circuitry.

 

[Audio-Omega]

So balanced has twice the voltage ? Does that provide better detail / resolution / bass ?

 

[mulveling]

Quote:

Originally Posted by Audio-Omega /img/forum/go_quote.gif So balanced has twice the voltage ? Does that provide better detail / resolution / bass ?

Yes, balanced operation will double the voltage which naturally results in 6db volume increase. But again, most decent headphone amps, balanced or not, are not lacking for output power/volume ability - just turn the dial until you reach the volume you prefer (unless your amp's gain is too low for your source/headphones, in which case you're screwed, but this is very rare anyways).

A well implemented balanced amp has technical advantages over its 2ch counterpart, for sure. What is at question is whether these advantages result in audible differences (in level-matched comparison), and if so then for whom is it worth paying for double the circuitry (4 channels vs 2) - *especially* when you consider what high quality single-ended amps of different designs are available for similar cost to the aforementioned balanced amp.

Again, I'll state my experience - I've heard magic on both kinds of amps. The balanced "magic" cost a LOT more

 

[ashmedai]

Quote:

Originally Posted by Audio-Omega /img/forum/go_quote.gif So balanced has twice the voltage ? Does that provide better detail / resolution / bass ?

Well...yes but no. If you just wanted twice the voltage, you could turn the volume knob up (like mulveling said). With ideal / perfect equipment, you could do that and it would work great. But it's not perfect.

A speaker is just a device that you run current through, with a positive lead and a negative lead. For a normal amp, you put the signal +V on the positive lead, and use GND for the negative lead. One note is that we assume GND is constant, but it never really is quite so. Another is that the results are limited by how quickly the change in the signal on +V can be effected.

For a balanced amp, instead of calling the negative lead GND you put an inverse signal on it such that -V = -(+V). Then when you want to produce a signal, you send +V up towards half the total potential difference you want, and -V downwards towards half the total potential difference you want.

Think of it as if you had two spheres that have to be 120 miles apart after one hour. You could send one away from you at 120 miles per hour, or you could send them in opposite directions at 60 miles per hour. You could wrangle the first option with good enough equipment - but it is much, much easier to do the second. Balanced operation allows us to achieve much better results without using parts that are obscenely more expensive and difficult to produce. (Of course, balanced is still really expensive...)

 

[XXII]

Quote:

Originally Posted by ashmedai /img/forum/go_quote.gif Think of it as if you had two spheres that have to be 120 miles apart after one hour. You could send one away from you at 120 miles per hour, or you could send them in opposite directions at 60 miles per hour. You could wrangle the first option with good enough equipment - but it is much, much easier to do the second. Balanced operation allows us to achieve much better results without using parts that are obscenely more expensive and difficult to produce. (Of course, balanced is still really expensive...)

I think this is a great analogy!

 

[mulveling]

Quote:

Originally Posted by XXII /img/forum/go_quote.gif I think this is a great analogy!

Yes, but let's not lose sight of the debate, just for a clever analogy

Analogies often oversimplify and overlook important contextual issues (still, it serves as a very nice introductory way to visualize balanced vs SE here). What's at debate here, is the point of diminishing returns for SE vs balanced. Using the car analogy, one could argue that a decently powerful SE headphone amp really has the capacity/headroom to go the equivalent of "500-1000 mph", when indeed all you need is to go "120mph". So then the question becomes more like which gives a smoother average ride at a net "120mph" for a given price point...a single super-premium luxury vehicle at cost of X dollars going 120mph or two more modest vehicles at cost of X/2 each going 60mph...

Sure, if you find the BEST amp circuit for your needs, and you have the funds, why not double it, there will be indisputable technical advantages (whether you can hear them or not is another matter)

For the rest of us...when does our upper-cost limit vs. diminishing returns kick in for both, and which is the best choice at that point?

 

[ashmedai]

Well, the biggest contextual issues are:

"Balanced is better. But is it enough better that the average listener will notice?"

and

"What is the relative quality-price efficiency for a balanced version of a given system versus other possible upgrades?"


The first is going to depend on the headphones used and on the listener, no question. The second is going to be in favor of balanced on some days and at some price points, and against it on and at others. I think the "best" design will always be the balanced one from a technical standpoint, but unless you're a DIYer with unlimited funds there are always optimizations in the economic and availability columns that will make us take a pragmatic view towards a purely technical improvement if it doesn't also make a noticeable experiential improvement.

Does balanced win, given that? Sometimes.

 

[Audio-Omega]

Balanced is a lot more expensive that's for sure.

 

[ert]

The freq response graphs here are interesting since they at least show there is a measurable (better?) difference between un/balanced configurations.

Quote:

Originally Posted by mulveling /img/forum/go_quote.gif there will be indisputable technical advantages

I'd be very interested in what these advantages are, since I've heard lots about them without really hearing them. A fully balanced amp only provides an advantage over single-ended in the areas of crosstalk and power, which should not be a concern if the amplifier is designed correctly and matched properly to the load. Furthermore, bridged amping (basically what a balanced amp is doing) has long known caveats such as loss of damping and distortion. I'm really curious why people think balanced amps are such a good idea, when you don't see them in high end stereo systems.

 

[DoYouRight]

Considering I am building a 6 board B22. I will NOT be using balanced phones atm. I will have a balanced DAC via a M-Audio transit for the optical out of my pc.

Is it not worth going balanced? Even if I want to try balanced in the future.

 

[grawk]

You're going through the trouble of building a 6 channel amp, but you won't reterminate headphones?