This combination adds regeneration to the QuadraVox algorithm.  Preset A forms a picked arpeggio pattern in any key or scale.  Preset B can be any delay algorithm. Here, the Tape Echo provides some feedback for the dotted 1/4 and 1/2 delay times.  The added complexity overlaps the 'fingerpicked' pattern back onto itself.

Preset A

Preset B (in series)