[shrimants]

I am kind of stuck on this. One thing I've heard is that balanced audio doesnt make a difference in sound quality unless you run cables long distances.

Through my own research I know that with balanced audio, instead of having Left+ and Ground, you have Left+, Left-, and ground. obviously the other channel is there too but for simplicity sake we'll leave that out.

Left+ gets one signal, lets say sin(x). Left- gets the inverse of that signal, -sin(x). Here is where my confusion starts. In my head, this means that the two signals should completely cancel each other out, and that overall voltage potential difference between the leads of the driver should be 0. However, after doing some math, I realized that the voltage may actually be doubled.

Which one is true? Is the voltage doubled? Is that one of the reasons balanced "works better"? Doesnt that mean you put 2x the signal into the headphones, which should cause a gain of 2? Does this also double the current going in to the headphone?

 

[stv014]

Quote:

Which one is true? Is the voltage doubled? Is that one of the reasons balanced "works better"? Doesnt that mean you put 2x the signal into the headphones, which should cause a gain of 2? Does this also double the current going in to the headphone?

Yes, the voltage is doubled, because it is the difference of the voltage on the terminals, i.e. sin(x) - -sin(x) = 2 * sin(x). Doubling the voltage on the headphone of course doubles the current, too (ignoring any non-linear distortion).
 

 

[temporaryname]

I have a Hifiman HM-801 with a balanced amplifier module and balanced HE-500's.
 
Not a single difference can be heard between the single ended HPO and the balanced HPO.
 
More over, not a single difference can be heard between my balanced HPO and my friends single ended HPO (he has the stock amp module).
 
I am a musician (playing music since I was 5 years old) and my friend is an accomplished sound engineer, and none of us heard a single difference.

 

[RexAeterna]

not only power but slew rate and impedance increases i believe. not 100% sure since i forgot but the increased impedance should not be an issue since voltage and current output is doubled.

 

[stv014]

Quote:

not only power but slew rate and impedance increases i believe. not 100% sure since i forgot but the increased impedance should not be an issue since voltage and current output is doubled.

The effects of increased output impedance do not depend on the maximum voltage and current output (the current limit is actually not increased). But it can be made low enough even with a balanced output anyway.
Slew rate is usually not a problem with a decent amplifier when driving headphones. For a 20 Vp-p signal at 48 kHz (the highest frequency with 96 kHz sample rate), you need about 3 V/us.
 

 

[RexAeterna]

The effects of increased output impedance do not depend on the maximum voltage and current output (the current limit is actually not increased). But it can be made low enough even with a balanced output anyway.
Slew rate is usually not a problem with a decent amplifier when driving headphones. For a 20 Vp-p signal at 48 kHz (the highest frequency with 96 kHz sample rate), you need about 3 V/us.

alllrighty then. i get it now. thanks for letting me know.