[ScubadudeSA]

That intermittent noise in the Phonitor 2730 is mono (i.e. the sound is centred between my eyes) and appears to be more of a problem with low impedance headphones. It's more audible with Beyerdynamic T1 Gen. 3 (32 Ohms)/AKG K812 (36 Ohms) than the Beyerdynamic T1 Gen. 2 (600 Ohms)/Focal Utopia (80 Ohms)/Mysphere 3.2 (110 Ohms). I wish there was a simple fix for this apart from using higher impedance headphones. It's still a great headphone amplifier.

That can be so annoying! The only noise I ever had on my 2730 sounded like muffled low pitch Morse code ... RF interference of some kind I would guess. It was intermittent and mono. Since I moved my microserver further away from my media computer I haven't heard it. Maybe I just got lucky with the cable routing this time, but I'm not moving anything to find out.