Topic: UCX 7/8 Phones Hiss Problem

Hello.

Recently I purchased a pair of AKG headphones and when I plug them to 7/8 I hear a strong hiss noise even at minus infinity.
The noise only occurs when using 7/8 outputs.
For instance if I plug the headphones to analog outputs there is no noise, but then I'm getting mono signal.
I tried Total Reset and it didn't help.

Any help would be appreciated.