"Knuckles" Machined Billet dual bass knob"Knuckles" Machined Billet dual bass knob. CNC machined from solid 6061 aluminum with custom machined billet knobs. These beauties are built with PAC LC1 bass knobs, as with any mechanical potentiometer, they do not have an infinite life span but the difference with our bass knobs is if the potentiometer does fail, it can easily be replaced with a new LC1 for $8 versus others that would have to be sent in to be repaired for a much higher cost, if they