This is for use with a Sonos?
I have a NAD PP2e.
My last preamp never turned off unless you turned it off at the plug, so the signal to the line in on the Sonos was always live. This meant it couldn't detect when to switch to the line input. This wasn't a huge deal, as you can switch on the app.
If you're going to switch the preamp off between listens, don't worry