Electro-Harmonix Pico Swello Envelope Attack Filter

Pico Swello is a polyphonic envelope filter that controls dynamics and attack for the instrument. With Swello you can get smooth transitions between notes in the same way as when you, for example, control the attack with the volume knob on the electric guitar and make so-called "swells". Here you don't have to think about controlling anything yourself because the pedal does the work, it also triggers the filter extremely quickly, so fast licks or arpeggios are no problem. The harder you set the attack filter, the more growing the sound becomes with more "swell" and sustain, perfect for synth-like, ambient sounds. 

The Attack control lets you decide how hard the filter should work and how soft the attack should be, this is matched with a Mod control where you can add modulation to the sound. The built-in low-pass filter has a separate Freq control for where you want to cut in the low register. 

Polyphonic Envelope Attack Filter
Attack control
Mod control for adding modulation to the signal
Low-pass filter with Freq control for adjusting where the filter should cut off
Volume control
Power supply included