DIY cab: how the heck does one wire a 1/4" input jack to a Apr 28, 2007im trying to make a 1X12 cab. ive got the chassis, and speaker. all i need now is some wiring and a 1/4 inch mono phone plug input jack. the people at radioshack are imbecles who cant even discern whether i need a closed-circuit or open-circuit 1/4 input jack, or even the kind of wiring i How to build a 1/4 to 1/8 stereo cable - Gearslutz Jun 19, 2016The same connector wiring is used to connect a balanced mono signal between a balanced output and a balanced input. However, 1/4-inch (6 mm) TRS jacks are commonly used as audio interface balanced inputs and outputs, but it is exceedingly rare to find a 1/8-inch (3) jack used for a balanced mono signal.