This is designed to fit a Les Paul or similar models that have 2 volume and 2 tone controls. It can be customized to fit any bass or guitar. A lot of guitar players claim position 3 of the varitone is barely useful and positions 4 & 5 are completely unusable. Part of the problem is the db cut. It was designed for very early amplifiers. The resistor at the input of the varitone is a 100K I build my varitones with a 51K resistor which reduces the db cut by 50%. The varitone capacitors are connected directly to ground through a choke in most cases.
Here is a photo of my latest example of the harness.
Position one is full bypass or wide open there is no db loss and the input signal is sent directly to the volume pot. When you Switch to position #2 the input signal travels through the 100K resistor and out the position 2 capacitor and then to ground. you will notice a slight db cut caused by the 51K or 100K resistor and the .001uf capacitor in series. As you switch through positions 2-6 each position has a little more db cut and is a little darker. Many varitones I build are replacements for the ES335, 345, 355 etc how ever many custom builds require different value capacitors. A strat is a little different than a tele to a les paul and so on. Gibson wires the varitone before the volume and tone controls using two volume pots and two tone the varitone is built using both poles of the 2 x 6 switch this allows for stereo output or dual mono using two jacks. For most other guitar and bass mods a mono switch will do and can be wired pre or post volume and tone controls.
For help with your next project or to order a custom harness mail to firstname.lastname@example.org
You can also find more about guitar wiring at my google site. Guitronix