If you have ~+3.3V at pin 8 of IC2 and pins 6 & 23 of the FV-1, the 3.3 L78L33 is good.
The toggle is intuitively selected & placed, so when it is in the "UP" position, the arpeggiation should be going upwards; alternating in the "MIDDLE" position; and downwards in the "DOWN" position.