Available as an assembled Module and as a DIY project.
This Module is currently available.
3 band equalizer with feedback
The MinEq is a 2hp 3 Band Equalizer Eurorack Module available as a Eurorack DIY Kit, PCB and Panel, or Built Module.
The newest version, V3 adds a rectified clipping feedback circuit to the EQ which produces a wider range of harmonic distortion, interactive self-oscillating, pseudo ring modulation, and richer filter esque timbres based on the input and knob positions. The new version does not invert the input anymore and does not self oscillate without an input present.
This hybrid Baxandall circuit provides +/- 20dB~ of boost or cut control over the Low, Mid and High frequency bands of an audio input. The circuit is capable of up to 20vpp~ of boost(with a 10vpp signal) and attenuation down to 1-2vpp depending on the input. The frequency bands are centered near 30Hz(Low), 1kHz(Mid), and 10kHz(High). The circuit is AC coupled and will invert the input(V2). With all the potentiometers at noon, the MinEq passes the signal relatively unaltered.
The graph of frequency response curves are from the National Semiconductor Handbook are an approximation of how the circuit will work exactly.
The only SMD component is the IC for V2. V3 is all through-hole and much easier to solder.
The Panel is reversible, one side with graphics and soulless side with less graphics.
These merchants probably sell this module. Huh?