Envelope filter

[paradigm_shift]

Is there an evelope filter that kicks in when the level goes below a certain level, rather than above(sensitivity?)?

[Explorer]

In other words, you want a filter which closes when there is signal present, and is open when there is no signal? Interesting.

[Spencer!]

You're referring to a downward sweep - many filters have this.

[paradigm_shift]

I want it to affect the decay of the note rather than the attack , if that makes sense?

[Skrogh]

I think i know what you mean. what you want is either a filter with a downward sweep, as Spencer said (check out the link in his signature) or a triggered filter (ex. the EHX bass micro synthesizer)

[AsianVoodoo]

You can control the moogerfooger LPf envelop with a pedal and make it do whatever you want!