When using the front-facing 6.3mm and Pentaconn headphone outputs, the Uniti Atom Headphone Edition will automatically mute the pre-amp outputs and turn on the headphone sockets - the headphone symbol on the Headphone button will illuminate to indicate that headphone output is active.
To activate the rear-panel 4-pin XLR output, simply toggle the Headphone button to active; this is because the 4-pin XLR connection cannot be automatically detected, so this is not automatic.
To switch to using the Uniti Atom Headphone Edition as a streaming pre-amp, simply toggle the headphone button off (the Headphone symbol will no longer be illuminated). You can keep any set of headphones plugged in – great for convenience, but also saving unnecessary wear and tear on the headphone jacks.
It is even possible to leave multiple sets of headphones attached, for example, if you and a friend wanted to listen at same time, or if you want to keep two sets of headphones ready to go. However, for optimal performance we'd recommend only having one set attached at a time.