Check the listing for details. Electro-Harmonix Nano Bassballs Envelope Filter Bass Effects Pedal LN. Condition: Used. Listed at 75.06 USD. The Electro Harmonix Nano Bassballs Twin Envelope Filter effects pedal has everything you loved about the original Bassballs in a pocket size. The human vocal-like sound of its two sweeping filters gives bass a strong presence under leads, or a commanding quality when out front. The resonant frequencies are engineered solidly into the full range of the bass guitar's strongest harmonics. Bassballs will respond to every bass note. The sweep is widely variable, and harmonic enrichment is available with the distortion switch.The Nano Bassballs comes in a small, die-cast case with rounded corners, saving valuable pedal board space. The footswitch selects your original signal or the filtered signal as the Bassballs output.