Rega Brio integrated - buzzzzz

I recently bought a latest version Rega Brio integrated amp locally for just $300.   It sounds fantastic honestly powering my Tekton Lores.   However, when volume is off and I’m within 3 feet of speakers I hear a buzz.   The buzz does not get louder as I turn up the volume.  I disconnected all other components except speakers and same result.  Power comes through a Tripp  Lite.   Note,  I’ve had an NAD and Onkyo in same set up, same room and both are dead quiet.    Seller was not forth coming and I’m certain he knew how ever my bad for not inspecting function of amp better when I auditioned it.   The buzz is so low I can deal with it if I can not resolve it.   But it bothers me knowing it’s there.   Any suggestions?   Do you think there’s an issue with the amp itself?   I love the sound of this amp so much I’d actually spend another $300 to get it repaired if I need to.