Have a friend (true,only one but its a start) who while his pas3 is in the shop is connecting his cd and tuner direct to his amp,( with "incredible results" I've heard of this before but it makes Me wonder why we use preamps other that having to use of phono or tape loops. He claims better or at least equal sound quality! What's going on here? I haven't tried this myself till I get more info, it just made me curious ie "shorter signal path, less ele. Between source and amp ect. Any downsides to this?