Summary: Hello All, I purchased a NAD C326BEE a year an a half ago and connected it to a pair of Klipsch RB-51 bookshelf speakers. After a couple of months, I would switch the unit On and he protection circuitry would immediately switch the amplifier Off. Sometimes I could switch it back on immediately, sometimes it would take 15 minutes or longer. I sent the unit for service and after a couple of weeks it was returned; Unfixed!. They could not find a problem!