Alexander Pedals La Calavera Phaser A full-fledged festival of phasing, La Calavera combines an offering to the more traditional effects of days gone by with the essence of rebirth and revolution. *Hint: Try Envelope mode mixed fully wet, with low Intensity for a volume sensing vibrato. Loco: This one is pretty crazy. The Tweak knob controls the feedback of the phase signal, and is linked to a ring modulator for some intense modulation effects. Might sound pretty gnarly, might sound pretty sweet. Smooth sounding ten-stage studio phaser, the Suave mode is wet and deep. The Tweak knob controls the amount of regeneration in the phase signal.