Yes, well I should have added that the point of the matter is, that whenever I hear a spike I do see it on the TM output busses, there is no spike impulse on the speakers otherwise, so its coming from the Babyface and/or the chain before. That might be different with other ADAT converters and setups but after all it would definitely help to be able to "hardware mute" the outputs.
I'm aware of the fact that most interfaces don't offer such a feature but due to all the possibilties you get with an RME interface + TM and the therefore wider range of applications it would just be REALLY NICE to be able to "turn off the lights". That's why the question, if that is any different with UCX / UFX..
Regards,
Markus