ST9Pro+ was developed based on the legendary overdrive Maxon ST9, which was released in the 80s and still well-known even after it was discontinued. ST9 was reborn as ST9Pro+ with new circuitry.

ST9Pro+ creates powerful, heavy, fat sound like a stack amp with midrange boost control. Wide range of setting, such as a booster, blues and hard rock, is available.

With newly added selectable diode clip circuitry and low-end boost circuitry, more powerful distortion and low-end boost are available.

Operating voltage 9V or 18V mode is switchable via an internal slide switch accessible through the units battery compartment. ST9Pro+ operates with battery or AC adaptor directly.

ST9Pro+ has increased dynamic headroom with internal operating voltage set at 18V. Stable high-quality sound is available as unintentionally-generated distortion is significantly reduced.

True Bypass Switching using 4PDT mechanical switch lets your instruments signal pass through a non-electronic bypass line when the effect is disengaged. MADE IN JAPAN