I really have no idea why the addition of Emotiva's filter created more hum. Did it further exacerbate the problem through some type of interaction with the ADA?
I'm not sure. The first things I connected to the line filter were the DSPs, and the louder hum was evident with that first step. Next I tried the ADAs, then the AVR. Ever since the first connection to the DSPs, the hum was louder and hasn't gone down since. I think something happened, but it's not like I heard anything or saw anything disturbing when hooking it up. The only evidence I have that something happened is the louder hum.
