ELECTRO-HARMONIX NANO DOCTOR Q Envelope Filter

The Doctor Q is an envelope filter that specializes in generating percussive punchy filter sweeps for a rhythmic groove.

• True bypass
• Simple one-knob range control
• Switch-selectable bass boost
• Responds to your personal picking style
• Tough and compact die-cast chassis
• 9-volt battery included
• Optional US96DC-200BI power supply available