I actually didn't find it myself. I unhooked everything and slowly put pieces back together and narrowed it down to my DAC and/or amp. I sent my DAC in for a check-up first. It checked out fine, so I sent my amp in for a check-up and that's when the loose (or broken?) connection was found.
I'm not sure if the SS pre actually blocked the interaction between the DAC and amp (it seems to have done so), or maybe the amp's connection coincidentally got worse when I hooked up the tube pre?? Either way, I never had the hum problem until I hooked up the tube pre...eventhough the tube pre had nothing to do with the problem at all. It was incredibly frustrating and it went on for months. Listening at night was almost impossible. I was very happy when it was all over and I had beautiful silence again.
This all happened about 18 months ago. I can't remember if the symptoms changed when I fiddled with power cords and interconnects like yours do, so I can't say if the problem is really the same or not. Good luck!
I'm not sure if the SS pre actually blocked the interaction between the DAC and amp (it seems to have done so), or maybe the amp's connection coincidentally got worse when I hooked up the tube pre?? Either way, I never had the hum problem until I hooked up the tube pre...eventhough the tube pre had nothing to do with the problem at all. It was incredibly frustrating and it went on for months. Listening at night was almost impossible. I was very happy when it was all over and I had beautiful silence again.
This all happened about 18 months ago. I can't remember if the symptoms changed when I fiddled with power cords and interconnects like yours do, so I can't say if the problem is really the same or not. Good luck!