EPF-19 is one of a few frequency-following circuits that I devised whilst exploring analog computing (seen here) which was begging to be applied to music. The circuit consists of a voltage-controlled filter that is set up to follow either/both the amplitude and frequency of signals presented to the input.

Features

• Standard Guitar input/output jacks

• Rugged stomp switch

• wide range "sensitivity" and "Q" control knobs

• "Lock" switch that controls pitch-following

• Hand-crafted aluminium enclosure designed for quick and easy access to the battery and components on the PCB

• Blue indicator LED

Electrical Specs

• DC input: 9V Battery < 1mA

• Frequency response: -6dB/Oct Below 7Hz and above 6kHz

• Filter range: 170Hz to 2.8kHz (unmodded)

This was my first exercise in getting a smooth assembly line running, which I learned a lot from. I'm treating it as a fundraiser for my home lab.

I'm very proud of the performance of this pedal. It goes from very subtle, to classic funk, to crazy synth sounds with the turn of a knob. Also, the unique and original pitch-following design creates another dimension of possibilities. Every unit is hand machined and assembled by me, in Canada, and comes with a manual, schematic, list of mods that I've been playing around with and, of course, a signature.