Quad VC Equalizer

Description

Quad Voltage Controlled Resonant Equalizer

• Four parametric equalizers with full voltage control connected in series.
• Individual output of previous channel is connected to switched pin of next channel input jack.
• Switchable to low-shelf on first channel, and to hi-shelf on fourth channel.
• Switchable to selfoscillation mode via DIP-switches. For v/oct trimming.
• Bipolar level control. +-16dB, CV range +-5V.
• Bandwidth control 0.8…24 semitones. CV range +-5V.
• Frequency control 10 octaves. CV range 0…10V.

The device has four identical bands with BP filters. Also the first band is switchable to HP mode and fourth band to LP to make low and high shelves. Also each band is switchable to boost or cut modes.

Every parameter has voltage control, also master CV ins for all bands.

Controls are:

FREQUENCY is peak frequency of a band. Range is 10 octaves. V/oct responce and initial frequency are trimmable with trimpots. CV range is 0…10V.

BANDWIDTH range is from 2 octaves to 0.06 octave at 3dB point. CV range is -5….5V.

LEVEL range is 14dB. CV range is 0…5V.

LM4040 precise voltage source for all offset voltages.

Temperature compensation.

Filters are based on hi-end quality THAT2180 chips. VCA for resonance gain (level control) is discrete.

Specs

• Power consumption: V+ 193mA, V- 193mA.
• module width: 24hp