Topic: Balanced headphone operation with UFX+

A while back when searching through the forums I found posts talking about how you can run balanced headphones on interfaces with 2 phone outputs and Totalmix connectivity. Recently I got my hands on Sennheiser's HD 820 with a 4.4mm balanced cable, and thought I'd give it a try.

I couldn't find a balanced 4.4mm to dual 6.35mm adapter, but I could find a balanced 4.4mm to dual 3.5mm. So I purchased that and two Sennheiser 3.5mm TRS to 6.35mm TRS adapters:
https://www.amazon.com/dp/B08284BT67?ps … ct_details
https://www.amazon.com/gp/product/B00L2 … &psc=1

I have it connected like this:
https://i.imgur.com/v7qhX2V.jpg

And configured like this in Totalmix:
https://i.imgur.com/7ed7WaH.png


Do I have this configured correctly? It sounds fine, but I guess where I'm confused is that I've been under the impression that running headphones with a balanced connection quadruples the power output. Yet, I have the faders and Level set to what they were when running the headphones off a single 6.35mm jack using a different cable.

Obviously I'm just a noob in this regard... Does this "hacked" method of running balanced headphones not increase power output? Or is it that even with increased power this doesn't affect volume?

Thanks for any help.

MADI FX, Fireface UFX+, ADI-648, HDSPe RayDAT, ADI-192 DD

2

Re: Balanced headphone operation with UFX+

This method does not give 4 x power, because the output stages are limited to the power available in unbalanced mode. But you get double the voltage, means 6 dB higher output level, so there should be a clear volume difference when using unbalanced and balanced connection and setup.

The problem: your routing is wrong, quite obvious when looking at the meters: the respective right and left output channel is dead. You need to use mono channels in the playback row, with Pan to center, sending left channel only to phones 1 and right channel only to phones 2 by setting the faders in playback row correctly.

Regards
Matthias Carstens
RME

3 (edited by Ninbura 2022-07-26 04:16:39)

Re: Balanced headphone operation with UFX+

Ah, I see. When configured as you've said I can hear the difference in volume:
https://i.imgur.com/ypStyrK.png


MC wrote:

This method does not give 4 x power, because the output stages are limited to the power available in unbalanced mode.

Is this a hardware limitation or a firmware / software limitation? Just interested in it all, thanks for the help.

MADI FX, Fireface UFX+, ADI-648, HDSPe RayDAT, ADI-192 DD