[carlmart]

Recently I bought a Fiio BTR5 headphone amp, and it has a 2.5mm balanced output.

So I began a research on what the "balanced headphone" term and concept actually meant.

First I looked around in Aliexpress what they might be offering as balanced headphones. Actually it's quite confusing, and the actual plug the supposedly "balanced" headphones used were not what seems to be any of the options used by balanced HP amplifiers: either 4-ring 2.5mm plugs or 4-pin XLR connectors.

Then I started a thread in DIYAudio on the matter, and had some discussions on what actually means balancing a headphone. Finally I got to some agreed consensus.

1) You need to rewire the headphones you plan to use, starting by cutting away the usual 1/4 or 1/8 stereo, 3-ring connectors soldered to the cable.
2) If the cable the HP uses is a shield + 2 wires, then you either eliminate it completely or add a similar length of a similar cable for one of the channels.
3) If you HP already has two wires, and not just one, you will probably be able to use both, and just change the termination plug.

What you need to do now is stop thinking of each HP speaker as having ground plus live connections, and start thinking of them as being R+ and R-, L+ and L-. Whis the standard denomination for balanced interfaces.

Balanced interfaces in audio are more common with low level signals, particularly microphones. The balanced arrangements reduces noise from external interference, and with low level signals they are mandatory.

Now let's be clear on something: it's debatable whether a balanced headphone interconnection is necessary. Except if you are using very long cables, like 10 meters or more. HP are already low impedance, so longer runs are allowed. Of course the HP amp should really be good for situations like that, with more than 2v outputs, and low noise.

But several reviews, one specifically on the Fiio preamp I would be using, said the audio was better on balanced output that the unbalanced one. So as I have a few Sony 7506 HPs, which are a film industry standard, that would allow me a fair comparison.

Here's video where they show how to disassemble a Sony HP which can be applied to modding other headphones.

https://www.google.com/search?clien...y+MDR-7506#kpvalbx=_dtTWYabYOdLD5OUPn5iM6A435

 

[HiGHFLYiN9]

Generally the single-ended and balanced output of a headphone amp are different; the balanced output provides more power, thus sounding preferable to most people. This makes "apples-to-apples" comparisons difficult. As you've noted you need 4 conductors. Mogami and Canare make good starquad cable for this purpose. 24-26 gauge is ideal for most headphones. You can connect the mesh shielding on the amp side for a floating shield if desired, but it is usually not necessary.