You could quite easily replace that original input socket with a standard 1/4 inch one and solder it to the circuit board via wires, what I would do is solder a 1M/1% metal film resistor between the Tip and Sleeve connections of the 1/4 inch socket before soldering the wires to it, that way the noise level when nothing's plugged in will be reduced, Marshall and Fender usually include the 1M resistor on the inputs of their amps, using a 1M/1% metal film resistor means that the input signal will see a light load while at the same the input will still be grounded when nothing's plugged in, the best of both worlds.
Last edited by DrNomis_44; 13-04-2019 at 04:53 PM.