Highly sensitive and reactive, the DOD Envelope Filter 440 Reissue is designed to give you a wide, sweepable range of control over your filter. Simple Level and Range controls give you the ability to choose your envelope's sensitivity and the frequency range of your envelope's sweep. And with an UP mode that'll give you a classic, resonant filter for guitarists and a DOWN setting for basses who like a little boom, the Envelope Filter 440 has a little something for everyone.