Whatever lash-up you choose [ Mr DERB ] insert a small matching transformer for isolation reasons. Ground loops suck
. Shadio Rack sells a nice 1:1 tranny for cheap and the Bogen WMT-1 is my favorite. Both of these transformers are available.
I no longer have stange EQ settings on my Class D 80M transmitter thanks to the matching tranny. Apparently the impedance match was so bad that it affected freq response in the transmiited audio and caused me to unfairly critisize Bruce's, (K7DYY) efforts.
Fred