Roland Jazz Chorus 120 The Roland Jazz Chorus 120 is one of the most celebrated and highly regarded solid state amplifiers ever created. What really set the jazz chorus apart in the world of solid state amplifiers is that it didn't attempt to sound tube-like, which was bold for the time. The jazz chorus found its way onto countless classic records and situated itself into countless sound rigs. A careful study of the jc's preamp topology lead to the creation of defiant jazz. Defiant jazz is a value for value, component for component recreation of the JC's clean channel (sans bright switch). Four controls rule over the sound of defiant jazz: volume, treble, mid, and bass. An internal charge pump takes 9v from a standard center negative power supply and steps it up to 36v, much like the original which stepped wall voltage down to 36v. Since this circuit quadruples the input voltage it is crucial to use only 9v.
