sentences:  The capacitor was removed from the circuit by the mid-1980's.A popular modification is to reintroduce the capacitor back into the circuit on more modern 330's, but it is usually attached to a push/pull potentiometer switch so it can be engaged by pulling up the knob and disengaged by pushing the knob back down - this allows for the more modern full bridge pickup sound as well as the thinner, more trebly sound.Rickenbacker 330's feature a slim headstock shape, but from a period around 1984 until 2007, they changed the headstock size to a wider shape.