M82 Bass Enveloper Filter lets you get funky.

For recreating that classic 70's funk bass sound, you need a bass enveloper filter. The MXR M82 Bass Enveloper Filter responds to the energy of your attack on the strings.  The harder you hit it, the greater the effect. The effect is a upward filter sweep that creates a "quack" sound, in addition to other neat tones. The MXR M82 is an analog enveloper that preserves your bass guitar's sonic integrity and character, and adds a wah effect. Taylor the shape of your bass tone and effects. Works for active and passive bass guitars.   Power:  9 volt battery or 9 volt AC adapter, such as the Dunlop ECB03.