Built around the legendary OC-44 Germanium transistor, the JMI Rangemaster Treble Booster Reissue is a replica of the famed Dallas Rangemaster of the 1960s used by rock royalty from Tony Iommi to Eric Clapton. Though billed as a treble boost, it was most often used as an overdrive to achieve a focused distortion. The unit has simple controls, featuring an on/off switch and boost control knob.