Schumann PLL

"Something that takes a signal, locks on to it, makes an identical signal, and as the signal changes, it detects the phase changes between the two and adjusts itself.

-John Shumann

 FTelletronica's "Shumann PLL" is an Analog Harmonizer that turns your instruments input into a squarewave and then adds intervals to your note.
It makes one note into a chord. Any triad out of one note.
You can control each voice indipendently from others with the specific knob (Multiplier, Divider, Squarewave)
The Loop control let you decide how accurately it follows your playing.
Controls are very interactive with each others.

When you push DRONE ON it will oscillate.
You can control the oscillation pitch with knobs A when SWITCH 1 is in the up position, with knobs A and B when it is in the centre position  and only by KNOB B when SWITCH 1 is in the down position.
When you push SWAP FREQ. you have the same features with SWITCH 2 and knobs C and D.

The upper swithes in the momentary section let you choose which voice control by the momentary action (multiplier, divider or both).
The interrupt/enable switches let you choose what kind of action the MOMENTARY switch will perform, independently for MULTIPLIER and DIVIDER voices.