Convert XLR to TRS Headphone Cable Issue

052rc

When you are talking about balanced headphones and headphone amps, it’s a marketing gimmick. There is no such thing.

Sorry, but you really don’t know what you’re talking about.

Here’s what’s really going on. Any time you see the work balanced, insert the word bridged. A balanced headphone amp is really a bridged amp.

No, they’re two different things. For example, a balanced differential amplifier. Or a balanced component that uses transformers at its inputs and output. Please get your facts straight.

Now that the ground is separated from the bridging process, each speaker in the headphone gets its own ground, just like any other pair of speakers.

Actually, what’s most common is that balanced headphone amplifiers use no ground to the headphone. That’s why there are only four conductors: a positive and negative phase for each channel. Note that the negative phase is just that - it’s not tied straight to ground.

I think the confusion may be that the line level inputs to the MX-HPA will accept both single ended connection via RCA jacks or balanced connection via the XLR jacks, on the rear of the unit. The headphone outputs on the front of the unit are not balanced. Balanced connections are only required for microphone or line-level signals that will be further amplified and any noise induced by a long cable needs to be eliminated. Headphones are basically mini speakers with a hot and neutral input to left and right just like a normal speaker. The typical TRS plug of most headphone cables uses the tip for the left hot signal, the ring for the right hot and the sleeve to provide neutral to both sides. The XLR portion of the combo jacks for the headphone out are probably wired for pin 2 left hot, pin 3 for right hot and pin 1 for neutral for both sides. The OP's complaint may stem from the XLR to TRS extension cable being mis-wired so that L and R are either being summed to mono or only the L or R are being fed to each ear cup, resulting in mono presentation. 

hertzhead

I think the confusion may be that the ... headphone outputs on the front of the unit are not balanced.

Not according to the manufacturer:

The MX-HPA is genuinely fully balanced from beginning
to end.

This review from Hi-Fi News seems authoritative. Note what appear to be combo balanced XLR headphone output jacks on the front panel, consistent with Musical Fidelity’s claims and HiFi News.

This is all pretty straightforward stuff, folks. 

cleeds, thank you for the link and clarification. I stand corrected. 

No problem! Thanks!