Two different tube phono stages I have run my 901 into the 47k mm section I get radio statio RFI that somtimes I can hear the words. It seems to fade in and out and varies from night to night and is quiet in the day time. The other annoyance when oil hot water furnace kicks on and off I get a crack thru speakers to varying degrees of loudness. This happens day or night. If I use the MC stage with set up trans I get none of the above? I hapen to like the sound better into the MM section. I do not want to start any MM vs. MC step up debate. Any ideas what is going on?