The Maxon SM-01 is the Super Metal variant from the 01 series released for the Japanese market in the 1980's. These use the same PCB layout as the Maxon/Ibanez SM-9 Super Metal and produces the famous thrash metal sound that guitarists have trouble replicating without a high wattage amp.
The pedal can scoop or boost the midrange and uses a pair of JRC4558 IC's to push a huge range of mid to high gain sounds with 5 knobs of tone shaping possibilities.
