the two pots are all you need, unless you want to add that 0.33uF cap that JohnA likes to add for D.C. shock protection between the star ground and the bridge(and cavity shielding) ground. shown in the lower left of his drawing.
"Silence is golden, but duct tape is silver. " -- Steve Hopton
"some people say happiness is just a State of mind...................... i think it should be a whole freakin' Country!" -- unklmickey