In the 3rd installment of her new video series, Carolina Eyck demonstrates the Arpanoid effects pedal by EarthQuaker Devices.
Carolina starts by walking through the features and modes of this cool arpeggiator pedal. Then, around the 3:47 mark, she performs some improvisations using both the Arpanoid and a Boss PS-6 pitch shifter/harmonizer pedal. To be honest, I was a little skeptical of how an arpeggiator could be used with a theremin, but Carolina's creativity has won me over.
For more ideas of effects pedals to use with your theremin, check out our recommended effects page.