This is a vintage 1960s Dallas Arbiter Rangemaster Treble Booster guitar pedal. This extremely coveted pedal, or effects unit rather, has been famously used by Eric Clapton, Brian May, Marc Bolan, Tony Iommi, and Ritchie Blackmore, to enhance the overall gain and presence of the notoriously dark British-made amps of the ’60s. With a simple tag board circuit consisting of a single germanium OC44, a Plessey electrolytic cap, and a couple additional caps and resistors, the unbelievably elementary design is ironically the most copied vintage effect ever made, yet, not even a faithful reproduction has quite been able to capture the essence of the incomparable Rangemaster.
This particular example sounds incredible. It literally makes any rig sound at least 25% better. It works perfectly, and though it’s not the cleanest example, for the most part it is intact and original. The original chrome border has long disappeared, as have the original rubber feet. The PP4 battery terminal has been replaced for a modern 9v adapter.