On my Sansui 350a, I only had an input connected to the aux ports, but accidently left the selector on phono. When I started to play music, I could hear the aux input, very faintly and noisily. Selecting aux played my input like normal. Is this just harmless, but interesting, interference? I normally use a Marantz 2235B and have never had this happen with that receiver (I know the Marantz is a significantly better engineered unit).