I recently added my tube pre back in which is very picky and seems very sensitive to ground loops.
When nothing is hooked to the pre but my amp - everything is quiet. When I connect the DS - I get a low level hum - which seems to go up w volume increases on the pre.
So I added a cheater plug to the DS. This ‘fixed’ the hum. Any guidance as to whether this is problematic for the DS ? Any suggestions on a better fix?
Do we agree this is probably a ground loop?
Thanks all. Tim