A $30-45 cable TV ground loop isolator from Amazon does the trick for me. No expensive conditioner solution needed (didn't work in my case anyway).
Some brands are way more susceptible than others, btw: My VAC 30/30 is the worst - the hum sounds like speaker short buzzing. Counterpoint SA3000 and SA5000 are pretty bad too - I thought they were broken! Lamms M1.1 are really good. Ditto Ayon CD2 and Sonic Frontiers Line-3.
Don't try the Radio Shack hack that somebody suggested on the web. :-)
Some brands are way more susceptible than others, btw: My VAC 30/30 is the worst - the hum sounds like speaker short buzzing. Counterpoint SA3000 and SA5000 are pretty bad too - I thought they were broken! Lamms M1.1 are really good. Ditto Ayon CD2 and Sonic Frontiers Line-3.
Don't try the Radio Shack hack that somebody suggested on the web. :-)