Riff Master OC44

Tony Iommi Is Your Friend

Inspired by Tony Iommi’s modified Dallas Arbiter Rangemaster effect unit used throughout the classic Black Sabbath recordings of the 1970’s, this pedal is designed to overdrive the front end of a slightly saturated tube amplifier into thick harmonic distortion while accentuating response and gain across a selected range of frequencies.

Each Fuzzlord Riff Master is loaded with a hand selected, exceptionally rare, NOS Phillips/Mullard “Red Dot” OC44 Germanium transistor as used in the original amp-top units from the 60’s.  A four-position Depth control sets the pass-band of boost, which can be adjusted from the stock treble boost setting through to a smooth, harmonically rich, full range boost.  

 The circuit provides gain of up to 24db across the boosted frequency range, which proves highly responsive to both pick attack and guitar volume setting.


BOOST – Adjusts the overall volume level and gain.

DEPTH – Sets the frequency range of the boost.  A larger range of boost yields less signal attenuation at lower frequencies, resulting in more bass, volume, sustain, and gain.


*In an effort to remain true to the vintage PNP transistor configuration used in the original circuit, the pedal is powered by a 9V battery and cannot be used by a standard power supply.

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Sound Demo (Previous Artwork, Same Exact Circuit)