You are right. I switched to attenuators because of hum. One of them was bad. So I switched back to RCA. Messed with the cables and the hum went away. Should of listened to you guys and went RCA right away. Sounds Fantastic
Thank you for the feed back, I always appreciate it because it helps me help others in the future. What you just found was not surprising. Hum, ground loops and other related issues could be hard to understand, and solving it sometimes require trial and error. I have read tons of info, even own a few books on the related topics and still found it very much a hit and miss thing on occasions. Even with no shortages of qualified electrical personnel, I lost count how many times my teams got into
real troubles in industrial power distribution systems because of grounding issues and electro magnetic interference, let alone just hum and other funny noise in home audio systems.
I hope your attenuators were refundable, I never liked those things but I understand why you wanted to stay with balanced. If you compared the level trims for the channels, I bet they all look more reasonable than those with the attenuators in place.