A ZVEX Effects Fuzz Factory (Vexter Series) guitar pedal, an iconic and highly interactive germanium fuzz pedal known for its wild, untamable, and experimental sonic capabilities. This specific unit is an early, vintage production version of the Vexter Series, which features a polished aluminum horizontal chassis with distinctive hand-silk-screened green and black graphics. The pedal is famous for its highly sensitive five-knob control layout, which alters the internal biasing of its classic 1960s-style germanium transistors:

• Vol (Volume): Controls the overall output level of the pedal.
• Gate: Silences hum, hiss, and feedback when you stop playing. Turning it up can create a modern, "spitty" or Velcro-like gated fuzz effect. 
• Comp (Compression): Adds attack characteristic when turned to the left, pinches the tone when turned to the right, and heavily controls the pedal's tendency to self-oscillate.
• Drive: Adjusts the amount of input distortion and increases sustain.

Connections & Features

• Footswitch: A heavy-duty, center-mounted metal true-bypass switch.
• Input / Output: Monophonic 1/4" jacks located on the sides (IN on the right, OUT on the left).
• Power: operates primarily on a 9V battery or an external DC power supply jack

• Stab (Stability): Controls the voltage feedback loop to the circuit. Keeping it turned all the way up delivers a relatively normal (though intense) fuzz. Backing it off forces the pedal into wild self-oscillating squeals, pitch-shifted feedback, and radio-like textures that interact directly with your guitar's volume knob.