Teenage Engineering OP-1 Crank
Turn your OP-1 Portable Synthesizer into a hand-cranked music box with the Crank Accessory from Teenage Engineering. Just mount it to the synthesizer’s blue knob and press Shift + Rec to activate the hand-crank recording (crank LFO) mode. You can now control the LFO speed with your hand to create a real vintage old-skool sound.
Mounts to Synthesizer's Blue Knob
Controls LFO Speed