Ok i have the mtx 6500D amp and i want to make my own bass knob (ebc) to connect to the ebc port on amp seeing i have two knocking around from old crossover and amp in the past i wanna know is it is possible to get one to work. The problem is that the ones i have have like a 3.5 mm headphone jack connection i was gunna cut it off and splice it with a 4 wire telephone cable but i need to know which wires to splice on the telephone cable can any one help me or show me the inside of one