02-01-2015, 08:19 PM
Yes you did that correctly, and a possible reason for the hum is maybe the wires being unshielded (does it use shielded wires between amp boards?)
Another - you are bypassing the volume regulator V1 (a-d) at the control input and that one provides some DC pulldown to GND so the wire would not float. Not sure what we are dealing with in there.
As for the tapping, there are plenty of elements that will exhibit microphonics.....
In short, I do not know enough about FM tuners and the apparatus being remote from me does not help, so maybe someone who knows it can troubleshoot it remotely.
Another - you are bypassing the volume regulator V1 (a-d) at the control input and that one provides some DC pulldown to GND so the wire would not float. Not sure what we are dealing with in there.
As for the tapping, there are plenty of elements that will exhibit microphonics.....
In short, I do not know enough about FM tuners and the apparatus being remote from me does not help, so maybe someone who knows it can troubleshoot it remotely.
