This is a vintage 1965 Dallas Arbiter Rangemaster Treble Booster guitar pedal. This extremely coveted pedal, serial number 161682, 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 Mullard (yellow jacket) 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. As briefly mentioned above, this super rare variant features what some believe to be the best transistor of the various possibilities; the Mullard OC44 Yellow Jacket, which is famous for producing slightly more bite and a more pronounced overdrive.
This particular example sounds incredible. It literally makes any rig sound at least 25% better. It works perfectly, and it actually one of the more cosmetically clean units of those which have been made available in recent years on eBay. The original plexi faceplate is structurally perfect, the original chrome border is miraculously intact and all (4) original grey rubber feet are present and installed. It is entirely original aside form the PP4 battery terminal has been replaced for a modern 9v adapter.