The Electro-Harmonix Doctor Q Nano Envelope Filter is a compact pedal that's not exactly small on the funk. The control layout is as simple as can be, with a single knob for range and a switchable bass boost when you need a little extra "oomph" to your tone. The envelope follower reacts dynamically to the volume of your picking, creating a wah-like tone that moves with how loud or soft you play individual notes or chords.