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Category: Music

Mutator VST Prototype

Most likely the best stand-alone rack mount stereo (two channel) filter, modulation and envelope follower unit. It has two great resonant filters with cutoff, envelope follower, and an LFO with 4 waveform types that can be linked or inverted. The Mutator is truly a great dance music machine. Run loops, synths, voice or entire mixes through this and filter them in stereo or dual mono. It sounds great!

The two filters are identical and totally independent of each other. The circuitry is analog too. The VCF (filters) have their own envelopes and there is a useful LFO for nice sweeping or pulsing effects. The LFO can also be MIDI synced to your music (it's a little tricky though).

There is a great implementation of MIDI control on the Mutator. Control the filter cutoff from your sequencer by hitting notes on the keyboard. That's it, the notes on your keyboard and the pitch-bend correspond to the different degrees of cutoff. There is no patch memory, but that's ok. The Mutator is a machine that's meant to be grabbed and played with live while either going to tape or live on stage. Filtering music for an effect has become very common these days and the Mutator is among the best machines for achieving this effect. It is THE SOUND used by Daft Punk and has also been used by Fatboy Slim, Future Sound of London, Depeche Mode, and Radiohead.


  • Effect/Bypass (2x)When in bypass mode audio in is connected directly to audio out.
  • Envelope Source (2x)Selects which signal drives the envelope follower circuit.In INT. position the sound being treated is used as the control signal for the envelope follower.In EXT. position the external control input becomes the envelope follower control signal.
  • Env/Gate (2x)In Env mode the envelope follower acts as its name implies, precisely following the amplitude of the control signal and producing a rapidly varying control signal which can be used to sweep the Cut-Off frequency of the Filter and/or volume level of the VCA. In Gate mode the envelope follower is either full on or completely off, depending on whether a controlling signal is above or below the gate threshold as set by the sensitivity control.When MIDI is implemented this switch also routes MIDI note on/off information to either gate or LFO re-trigger.
  • Sensitivity (2x)In Env mode this sets the optimum drive level for the envelope follower circuit. Too low and the LED only glows faintly, too high and the LED is driven hard on. The optimum setting is when the LED peaks in brightness at the loudest points of the control signal.In Gate mode the sensitivity control sets the threshold level at which the gate operates.
  • Attack (2x)This adds an attack time (fade-in) at the front of the envelope. When set to zero (fully anti-clockwise) it has no effect on the envelope contour - fully clockwise it gives up to 2 seconds of fade-in.
  • Release (2x)This adds a variable release “tail” to the envelope. Even after the control input signal has died away up to 5 seconds of fade-out may be added by this control. Setting this control to small amounts can be useful for smoothing out rapidly changing envelopes when in Env mode.
  • Rate control (of LFO) (2x)This changes the sweep rate of the low frequency oscillator, from about one cycle every ten seconds to 100 cycles per second. Note that when the Link switch is on only the rate control of Channel 1 has any effect as it is being used to control both channels (LFO 2 is switched out when Link is in).
  • Waveform (2x)Selects between the four available low frequency oscillator waveforms - Triangle, Square, Ramp up and Ramp down.
  • LFO Depth (2x)Determines the amount of LFO sweep sent to the filter and/or voltage controlled amplifier.
  • VCA/Both/VCF (2x)Selects whether the output of the LFO sweeps the voltage-contolled amplifier, the Voltage-controlled filter, or both simultaneously.
  • Envelope Sweep (2x)Determines the amount of filter frequency sweep (up or down) being sent to the voltage controlled filter from the envelope follower.
  • Cut-Off Frequency (2x)This sets the centre roll-off frequency of the voltage-controlled filter.
  • Resonance (2x)Sets the Resonance (or Q) of the VCF. High values produce self-oscillation.
  • VCA In/Out (2x)Selects whether the final output goes through the voltage-controlled amplifier or is taken from the VCF output.
  • Link Normal/InvertLFO 1 can be sent to channel 2 for stereo panning/cross-modulation effects. The Normal/Invert switch inverts the output of LF0 1 that is being sent to channel 2. This is particularly useful for stereo effects.
  • Link In/OutWhen in, LFO 1 is sent to both channels (for stereo effects), when out, LFO 1 affects channel one, and LFO 2 affects channel two

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