Stereo JTM-style socket
Use a stereo jack socket for creative wiring options
This is a 3-pole version of the classic chrome nosed jack socket. In most implementations, the three poles are used for stereo connections with TSR jack plugs: left, right and a common ground. But the extra connections on this socket are useful even with regular guitar cables and mono jack plugs (known as TS). The reason is that when you insert a normal mono (TS, 2-pole) jack plug, the centre lug on this jack socket connects to the sleeve (ground) of the mono jack plug, and then to the amplifier’s ground.
You can use this creatively to add extra voicing options to your amplifier. For example, if you have an amplifier with 4 inputs, you could wire one of them such that an extra cathode bypass cap is grounded when that particular input is used – perhaps to give a bass boost. The unswitched lug of the same pole is also lifted from any connection when a jack plug is inserted, which means that you can also use this socket to break a connection for a different circuit change. One caveat: make sure you are only connecting signal voltages here!
Dimensions & info
Made by Neutrik. The jack socket requires a 11.2mm hole in the control panel, to seat the black outer ring. It comes with a single washer to use for mounting.