I have a new, newer used, original Stax socket for sale.
This is the round type, black, 5-pin, Pro-Bias Socket that goes into the Stax electrostatic amps on the front plate for connecting the ear speakers.
Do you still have any Stax Pro 5 pin sockets left? Looking for this one or the CNC'd version you previously posted. Please PM me as I can't PM you... my account is too new and still being moderated.