Maybe you’re right. My experience is with radios, where it’s possible that high frequency noise is conducted into the RF section rather than into the audio ampl

Maybe you’re right. My experience is with radios, where it’s possible that high frequency noise is conducted into the RF section rather than into the audio amplifier. I know that in one case, both my transmitted signal and received audio output were absolute garbage (edit: because it was picking up noise from the vehicle ignition) until I added a choke to the power input wiring.