This compressor/sustain pedal allows you to get a range of tones, from a twangy and snappy bite to a smooth legato. With volume, attack and compression knobs you can adjust the compression parameters to get the exact sound you want. A nice addition is the Emphasis control, which works like a tone knob, but which lets you select which range of the frequency spectrum you want emphasised as the signal is compressed. This way you can get some really bassy jazz tones, or brittle top end, and everything in between.