amp input jack wiring issue

[miner49er11]

I have a 70's vintage Seymour Duncan Bass 400 ss amp that works great with my GS410 and 210MBX. The input jack is a standard 2-conductor TS jack. It doesn't ground the tip when a plug isn't in it. Can I install a jack that grounds the tip when the plug is pulled without damaging the amp? In its current state, if you turn up the volume pot with no guitar plugged in , it tends to make some strange noises and might be burning my HF driver voice coil for some reason . It did this once. Anyway, can I ground the preamp input safely? There's only one input jack. ~Pete

[Bassamatic]

Get a cord with the Neutrik grounding plug on it. It has an internal switch. When the cord is removed from the guitar, it automatically grounds the plug so it is silent. No clicks, pops or hum.

and YES - the input can be shorted with no problem.

When you have time, you need to find out what is causing this noise in your preamp!