Chippy - I've just received a call from Bob of NAD in Canada. He is aware of the noise problem with a few "high voltage" units and the replacement boards that include the faulty component are now with Sevenoaks. It's not a recall, so the onus is on you to arrange for the repair. Chris is the guy at Sevenoaks who knows all about NAD. I hope this helps. PeterPat - can I ask, do you hear a crackling noise coming from your M33, and also a quiet hum, if you listen to it close up?
I got an M33 late November (from Sevenoaks) and straight away upon turning it on, I was surprised to hear it crackling and humming. The hum is easily audible in my room (when the room is silent) from my regular listening position about 10 feet away, so I immediately decided this was unacceptable and I arrange a replacement on the basis that this must be defective (Sevenoaks agreed).
I got the replacement just before Christmas, and it's exactly the same. Sevenoaks have contacted NAD who have said its a known problem with M33's on UK mains voltage which they will fix with a recall at some point in the near future, so for now I am keeping this one.
But I am just surprised no-one else has mentioned it. Does yours do this?
PS - I'm hoping that my M33 problems (shutting down occasionally or not booting up first thing) will be fixed by the firmware package Bob has sent to me. If it works, it'll save me having to send it to Sevenoaks. A job for the weekend.