Schumann PLL

FTelettronica is an Italian one-man shop in Isola del Liri, founded in 2008. They build faithful clones of rare and discontinued effects, using Alpha pots, Neutrik/Lumberg jacks, and a 2-year warranty.

The Schumann PLL converts your input to a squarewave and adds intervals through a phase-locked loop. Multiplier, Divider, Squarewave, and Loop knobs control pitch tracking and harmonic relationships. Drone section with frequency control switches. Momentary switches for real-time voice selection. Upper switches select multiplier, divider, or both. 26mA, 922g, 200x126mm, powder-coated. True bypass.

PLL-based harmonizers are gloriously imprecise. The 'Loop' knob controls how tightly the circuit tracks your input, from accurate intervals to complete pitch mayhem. All controls interact with each other.