Altered States

Dual state-variable filter

Altered States is a dual analog state variable filter in a 20hp module.

The filter cores are 12db/oct and based around the clean and reliable 2164 Quad VCA chipset and offers full voltage control over cutoff frequency and resonance as well as individual outputs for each filter response, including a variable state output with manual as well as voltage control.

The filters are identical in featureset, and featureset is as follows:


Frequency cutoff control knob
Resonance amount control knob
Frequency cutoff CV attenuverter knob
Input level attenuator with overdrive knob
Variable state control minishaft type
Resonance amount CV attenuverter minishaft type


Filter audio input
Frequency cutoff CV input
Frequency cutoff 1V/O scaled input
Resonance amount CV input
Variable state CV input
Variable state output (LP-Notch-HP)
Lowpass output
Bandpass output
Highpass output

Also available are a toggle switches for Combine (links the filter B frequency cutoff controls to filter A), and serial or parallel input routing.

Altered States is a highly versatile dual filter, the input and resonance controls have plenty of range to dial in anything from smooth and clean to harsh, overdriven and screaming resonant tones. The cores are very stable and will give you around 5 octaves of 1V/O tracking sine wave self-oscillation, the LP, BP and HP outputs each have a different phased sine. The state outputs offer seamless fading between lowpass and highpass filter response, with an all-pass/notch response around 50% of the knob setting. With voltage control available on frequency cutoff as well as on resonance and state outs, the Altered States is perfectly suited for the modular environment.

  • 112 mA +12V
  • 106 mA -12V
  • 0 mA 5V
  • 45 mm deep
  • Ø 4.50 (2 Votes) Average Rating

Module is available as a DIY project only.

This Module is currently available.

$285 Price in € submitted Aug 27th 2018, 15:46 by mindsnared | last Change Apr 1st 2019, 18:56 by ZiZLoG

7 Users are observing this