excuse me poma, tho _slightly_ off topic as you say, i would like to add this:
On 07/07/2014 08:47 AM, Doug wrote: <<>>
There are also some small ferrite toroids that could be installed on some wires inside the amp. That would involve unsoldering the wire, slipping the core over the wire, and soldering it back.
in addition, a 1 turn wrap may be more effective, with checking for change in frequency range.
putting 2 to 4 wraps of ac cord around a ferrite toroid next to chassis will also help.
see: https://en.wikipedia.org/wiki/Choke_%28electronics%29 https://en.wikipedia.org/wiki/Ferrite_bead