IN MANUFACTURING

 

Based on Discrete Blacksea gain cells (6 total).

 

12HP

 

 

• Two parametric bandpass filters with full voltage control connected in parallel.
• Two main modes selectable by switch - Equalizer (when input signal is presented at the output), and Resonator (when input signal is not presented at the output).
• Switchable to low-shelf on first channel, and to hi-shelf on second channel.
• Switchable to selfoscillation mode via DIP-switches. For v/oct trimming.
• Overload LED help to avoid clipping.
• Bipolar level control. +-16dB, CV range +-5V.
• Bandwidth control 0.5...24 semitones. CV range +-5V.
• Frequency control 10 octaves. CV range 0...10V.
• Power consumption: V+ 105mA, V- 100mA.

 

 

Paypal: info(at)greenexpo.by

 

Assembled module $380 + $15 shipping.

 

 

Photos:

 

 

 

PLOTS.

 

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.

 

 

Equalizer mode, BW - min, Level - max pos, Frequencies at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Volts CV.

 

Resonator mode, BW - min, Level - max pos, Frequencies at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Volts CV.

 

 

Equalizer mode, BW - min, Level - min neg, Frequencies at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Volts CV.

 

 

 

Resonator mode, BW - min, Level - min neg, Frequencies at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Volts CV. Signal is inverted.

 

 

Equalizer mode, BW - middle, Level - max pos, Frequencies at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Volts CV.

 

 

 

Equalizer mode, BW - max, Level - max pos, Frequencies at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Volts CV.

 

 

 

Equalizer mode, Level - max pos, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Equalizer mode, Level - min neg, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Resonator mode, Level - max pos, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

 

Resonator mode, Level - min neg, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV. Signal is inverted.

 

 

 

 

Equalizer mode, Low shelv boost. Level - max pos, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Equalizer mode, Low shelv cut. Level - min neg, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Equalizer mode, High shelv boost. Level - max pos, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Equalizer mode, High shelv cut. Level - min neg, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Resonator mode, Low shelv boost. Level - max pos, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Resonator mode, High shelv boost. Level - max pos, Bandwidth at -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Equalizer mode, BW - middle, frequency 1 kHz, Levels at 0, 1, 2, 3, 4, 5 Volts CV.

 

 

 

Equalizer mode, BW - middle, frequency 1 kHz, Levels at 0, -1, -2, -3, -4, -5 Volts CV.

 

 

 

Equalizer mode. Mixing result from all four bands is obviously. here two bands with full positive Level, two other bands with full negative Level.

 

 

 

 

Equalizer mode. Four bands with positive Levels. Yellow - result.

 

 

 

Resonator mode. The same four bands with positive Levels. Yellow - result.

 

 

 

Equalizer mode. Make red band full negative Level, other three bands with positive Levels. Yellow - result.

 

 

 

Resonator mode. The same. Make red band full negative Level, other three bands with positive Levels. Yellow - result.

 

 

 

Resonator mode. The same. Make blue band wider.

 

 

Resonator mode. Green bands full negative Level, Red bands with positive Levels. Yellow - result.

 

 

Resonator mode. Green bands full negative Level, Red bands with positive Levels. Yellow - result.

 

 

The same in Equalizer mode:

 

 

 

(c) L-1 Synhesizer. E-mail: info@greenexpo.by