[Steve Eddy]

Quote:

Originally Posted by Hirsch /img/forum/go_quote.gif Balanced headphones use are not grounded in the usual sense. Both sides of the headphone have active amplification, and the headphone itself is not grounded.

But what is "ground" to a headphone? At its most fundamental, it's just a coil of wire which has a voltage applied across it and current running through it. What does it know of "ground"?

The post you refer to, when it mentions ground, it's speaking not so much of ground, but rather a common return path shared by the left and right headphone drivers. However, that issue has nothing in particular to do with balanced amplifiers. You may have an unbalanced amplifier in which there is no common return path for the left and right headphone drivers, or you may have a balanced amplifier which does.

Quote:

A balanced stereo headphone amp actually has four channels of amplification.

It can, but it's not any sort of requirement. I can show you a balanced stereo headphone amp with just two "channels" of amplification.

Quote:

So, there's a bit more going on than "balance of impedances, i.e. the impedances of each line to ground" (which is not all that relevant in the absence of a ground) and common-mode noise rejection going on in a balanced headphone rig.

Yes. But while there may be more going on than a balance of impedances, the simple point of my comment was that that's precisely what the term "balanced" refers to.

se

 

[fierce_freak]

Quote:

Originally Posted by J-Pak /img/forum/go_quote.gif I will be balancing a stock HD650 cable and trying it out of my Lavry DA10's XLR outs and the built in headphone amp. I plan on making a thread with differences.

I'm extremely interested on hearing what you think. I just picked up a DA10 and am thinking about grabbing another pair of HD650's to run straight from the XLR outs (used to have HD650, thinking running balanced would fix my problems with 'em).

 

[pageman99]

Hmm... it's been awhile and my physics training is primarily theoretical, but I thought high impedance requires higher voltage to drive well, while low impedance requires higher current to drive well.

Hence balancing HD650's for example should show significant improvement because balanced outs generally have a higher voltage than S/PDIF.

Can someone comment on this, or am I simply wrong?

 

[Hirsch]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif But what is "ground" to a headphone? At its most fundamental, it's just a coil of wire which has a voltage applied across it and current running through it. What does it know of "ground"?

Not a thing. It is neither but can be driven either way, of course.

Quote:

The post you refer to, when it mentions ground, it's speaking not so much of ground, but rather a common return path shared by the left and right headphone drivers. However, that issue has nothing in particular to do with balanced amplifiers. You may have an unbalanced amplifier in which there is no common return path for the left and right headphone drivers, or you may have a balanced amplifier which does.

No, you've missed this one, I think. What you say is correct. However, one of the big advantages of a good balanced amp is that you actually have separate amplifiers driving each phase of the signal.
Quote:

It can, but it's not any sort of requirement. I can show you a balanced stereo headphone amp with just two "channels" of amplification.

So can I, but it won't have the same sonic effect as one that has active amplification on both sides of the signal. Quote:

Yes. But while there may be more going on than a balance of impedances, the simple point of my comment was that that's precisely what the term "balanced" refers to. se

Actually, with headphones I see it more as a balance of voltages, not impedances. The term "balance" can have several meanings, and I think that while using it for headphones was convenient when the phrase was coined, it's also a bit of a misnomer given the normal use of the term in audio as a means of common-mode noise rejection. With headphones, you get increased slew rate, added power, lower power demands on each amplifier, and increased channel isolation. You can also get some common-mode noise rejection, as common mode noise may be in-phase in both channels, and will cancel out at the headphone. However, that's a side-effect, not the purpose, of balanced headphones.

 

[aryaah]

My experience is limited to the Apogee Mini DAC as my balanced source and using the Ray Samuels B-52. All XLR connectors.
The HD650 with balanced Equinox cable is much more enjoyable than the stock HD650 cable (using the single end output of this amplifier.) Both types of output using the HD650 are musically/sonically strong in the setting of the B-52 but there is a clear benefit to the balanced headphone output.

 

[fierce_freak]

Can you briefly describe the differences? Thanks, aryaah