L-1 Dual Discrete EQ + Resonator

The device consists of two band-pass filters. Every band has independent controls (with a knob and CV input) on Frequency, Bandwith, and bipolar Level. Also CV inputs for master control all bands. Equalizer/Resonator switch is for switching between two main modes. Equalizer mode works as average equalizer - boosts (with positive Level) or cuts (with negative Level) frequency bands from input signal. Resonator mode works as band-pass filters. It boosts frequency bands with positive Level, and inverts frequency bands with negative level.

Frequency knob controls 10 octaves from 16 Hz to 16 kHz. Frequency CV inputs are 1V/oct. Frequency clips if to modulate over 13th octave at cutoff about 100 kHz. It's far ultrasonic but possible to reach if to modulate Frequency CV with fully open Frequency knob. Sometimes this clipping sounds nice, but sometimess unwanted - make less Level or Frequency then. Bandwith controls width of frequency band from 0.5 to 24 semitones at -3dB from the peack level. CV input from -5V thinnest to +5V thickest. Level is bipolar. Zero at the center, right side positive, left side negative. Boosts or cuts 16 dB at each channel. Response curve is semi-exponential, as in mixers.

Overload LED lights when output signal amplitude exeeds 11V - it is much higher than 5V modular level, signal really clips, make less level or frequency. Band/shelve switches from band to low-shelf filter at first channel, and to high-shelf filter at fourth channel. Oscillation switches turn on resonance loop, and switch a channel into selfoscillation if thin Bandwidth and max Level. It's for checking frequencies and v/oct trimming.