Thanks, Nick.

I _am_ intending to use binding posts at both ends. I just thought it
would be aesthetically neater at the amplifier end to have a wall
plate, with the binding posts protruding from the wall plate.

Perhaps, I need a bigger soldering iron (my electronics iron may not be
meaty enough to heat up heavy gauge copper).

I would still prefer to screw the cable to the back of the plate,
rather than solder it though.