mains hum prob


2008-03-23 1:28 pm
when i plug my new pc (which is earthed) into my hifi system - i get a
terrible hum

this can be eliminated by unplugging my other devices
( tv dvd player etc ) from the hifi amp

the pc is connected via the the headphone o/p
to a line in on the amp(phono)

my other devices and the amplifier are double insulated
and have no mains earths

has anyone had the same experience - whats the best fix

thanks in advance for any info

stoke on trent