Anybody who use RME Babyface have that same "problems"? Please help.

I tried two kind of phones /manufacturs/-Beyerdynamic and Philips. Same situation.

Ok. I've checked everything once again. So, it looks like some kind of electric problem- only when I touch the wheel (knob) or unit, I hear in headphones - electric voices (like short circuit). Unit was connect to the desktop. When I unplugg desktop + babyface from grid, the voices dissapear,nothing. Second, I also have problem with wheel (like some other users), it looks like here - http://www.rme- forom audio.de/forum/viewtopic.php?id=12036 . I have silver edition. And last thing, When I work in Windows, I hear hum (in phones at >0 DB in total mix) + some electric voices when I touch the unit. I've checked the unit on three diffrent desktops. Those problems are the same. What should I do?

Ok, Bandido, I know that you have problem with hum, but what about "electric voice - like short circuit ?" - Do you hear that in your phones when you turn on laptop/turn off (but use with AC power)? I hear that voices, especially when I turn off desktop, but also hear in system - windows. Anybody who has Babyface blue, black, red etc. also has that problems? Because I dont know what to do now. Also, I wrote that I have problem with wheel (knob).... And what now RME? I buy interface, for 550 Euro and now I must have that issues? Warranty?

Hey, a guy in this thread got his unit exchanged and the problem resolved:
http://www.rme-audio.de/forum/viewtopic.php?id=12070

It sounds to me your noise is not only from the desktop but also other connecting devices, why not discoonectting them one by one to locate the source?

Hi max2004,
I understand your fustration over this as I have been through similar situation often. The challenge is always to pinpoint the issue.
Presumably your headphone is plugged in the BBF. If you have a realy bad ground, pull the headphone plug out and touch the tip to the BBF socket outer conductor, you should hear the ground loop noise, the worse the ground the louder the noise. But you are always going to hear something this way. If you have a multimeter, switch to AC Volt, one pen to your hand one pen to the outer conductor, you should get around or less than 10 Volts, if it's very high, say tens of volts, that means your desktop has very bad or no ground as your BBF ground =headphone socket outer conductor=XLR metal case= USB 5V ground=desktop metal case= grid earth pin. The resistence between these points should be the lower the better, say less than 1 ohm.
OK, I was able to reproduce this fault as the following. Funny enough, Apple Macbook Pro power adapter is supplied with two connection methods, one with a cable and it has ground pins in the grid connector, the other one is a simple adapter to suit different country standard which has only 2 pins! no ground connection! By using this no ground connection, I was able to hear the electricity noise if I use a high sensitivity headphone (Bose QC2) and switch the volume in totalmix to maximum. And the AC voltage between my hand and BBF case is about more than 30 VAC!

If I were you I would carefullly check if your grid ground pin is working or not.

Why some equipment will still work OK under such environment? The answer is if the audio has balance input and output plus isolation transformers, if equipment uses traditional transformer based linear power supply instead of switching mode regulators without ground pin.....

But isolation transformer can compromise audio quality, I guess, and increase the size and weight of the device.
Hope you get  this sorted