Well, I'd also conclude that you have a ground loop problem -- which is certainly not unusual with cable boxes. I had this same problem, as has my son. The problem in my system and my son's system were both solved by installing a ground loop isolator, which you can get at Radio Shack for around $20. Try getting a ground loop isolator, and if it doesn't cure your problem you can take it back to Rat Shack for a refund.
BAD hum from catv box
Since I live out in the weeds of Wisconsin,I can't pick up
any jazz channels on F.M.
So I got an extra cable box for just the music channels{no tv hooked up].I ran from the analog audio outs to the premp.
with the volume all the way of it hummed really loud,like a really bad ground.If I turned the volume knobs up some,music never got as lound as the hum.Swapped out catv boxes,cables, checked for ground loops etc.with no improvement.I using a Dan Ovando passive pre,to s.s. amp,all
power conditioned,to a pair of K-horns.
Anyone have any idea what's going on?
any jazz channels on F.M.
So I got an extra cable box for just the music channels{no tv hooked up].I ran from the analog audio outs to the premp.
with the volume all the way of it hummed really loud,like a really bad ground.If I turned the volume knobs up some,music never got as lound as the hum.Swapped out catv boxes,cables, checked for ground loops etc.with no improvement.I using a Dan Ovando passive pre,to s.s. amp,all
power conditioned,to a pair of K-horns.
Anyone have any idea what's going on?