It is possible to copy all the parameters of a filter into the other one, using drag/drop on top level tabs.

Filter types

There are 20 filter types available:

• Lowpass: the Cutoff slider controls the cutoff frequency of the filter, and the Rez slider controls the filter resonance. This filter comes with -12dB/-24dB/-36dB slopes.
• Highpass: Cutoff and Rez sliders behave like in the lowpass filter.
• Bandpass: the Cutoff slider controls the center frequency of the filter, and the Rez slider controls the filter bandpass width. Like the Highpass and Lowpass, this filter comes with -12dB/-24dB/-36dB slopes.
• Notch: the Cutoff slider controls the center frequency of the filter, and the Rez slider controls the depth of the notch.
• “Analog” Lowpass: this is a different model of a lowpass filter (again with -12dB/-24dB/-36dB variants), with a distinct analog flavor, a lot of warmth and very aggressive resonance.
• “Analog” Highpass: an highpass version of the previous filter.
• Comb filter: this filter mixes the signal with a delayed version of itself, bringing in lovely ringing tones, and is especially effective on drum loops. The delay time is controlled by the cutoff envelope.
• Allpass filter: this filter changes the phase of some frequencies in the input signal. These frequencies are controlled cutoff slider (the resonance control has no effect on the allpass filter). This filter can be used in 2 different ways:
  • If the output signal is mixed with the input, and the filter cutoff is modulated using an envelope, some frequencies are canceled out as the cutoff is swept by the envelope, leading in a slight phasing effect.
  • If the output signal is played raw, there is no audible difference between the input and the ouput. This is a convenient way to pan a raw oscillator output: send it through an allpass type filter, and use the filter output panning curves.

Regardless of the filter mode, the Cutoff Env. Mod slider is used to control the amount of cutoff modulation applied by the cutoff envelope.
The Resonance Env. Mod slider works similarly, with the resonance envelope. With extreme resonance settings, the output of the filter can get rather hot, so you have the choice between:

• clipping the output at the filter level, by enabling the “clip” button next to the resonance slider
• or adjusting the main output level, in the global controls section, to avoid clipping.

The Feedback1 slider controls the amount of Filter1 that is fed back into the current filter (so on the Filter1 page, it is self-feedback). The Feedback2 slider control the amount for Filter2.

Feedback can really increase the resonance output, so watch for clipping ! Make sure you enable clipping when playing around with filter feedback !

Filter “morphable” waveshaper

The filtered signal can be processed by variable waveshaper. It is similar to the one used in the oscillators stage, except that its shape can be morphed (hence the name) between two different curves.
When the “waveshape morph” slider is set to 0, the waveshaping window displays (and allows to edit) the first waveshaper curve. When the “waveshape morph” slider is set to 100, the second curve is selected. Anywhere in between, the waveshaper is morphing between the 2 curves.

Filter envelopes

The filter envelopes work just like the oscillators envelopes. There are 3 envelopes per filter, controlling the filter cutoff and resonance, as well as the amount of morphable waveshaping used to distort the filter output.

Filter keyboard tracking

This control works just like the similar control on the oscillator pages. There are 7 tracking curves available:

• Cutoff level, to control the filter frequency cutoff.
• Cutoff time, to control the filter envelope segments times (in conjunction with the dark triangles at the bottom of the envelope window).
• Rez, to control the filter resonance value.
• Pan, to control the filter output pan. Since the filter outputs go into the effects section, but it is possible to make the played note position control the left/right stereo image of the audio going into the effects.
• Rez Time, to control the filter resonance envelope segment times.
• WS Time, to control the waveshaper envelope segment times.
• WS Amount, to control the amount of the morphable waveshaper effect.

It is possible to set a low-pass filter (-12dB/oct) with a cutoff of 100, which is basically “no-effect”, and then use the Pan control to get an unfiltered sound that is panned from left to right. The allpass filter can also be used similarly (and with even less CPU usage).

Filter Velocity and Aftertouch tracking

Each filter has 10 associated velocity tracking curves, and 4 aftertouch curves. They work just like the similar control on the oscillator pages.The available velocity curves are:

• Cutoff Level, to control the filter cutoff.
• Cutoff Time, to control the filter envelope time (in conjunction with the downwards triangles at the bottom of the envelope window).
• Rez, to control the filter resonance.
• Pan, to control the filter output stereo image.
• Rez Time, to control the filter envelope resonance segment times
• WS Amount, to control the amount of the morphable waveshaper effect.
• WS Time, to control the waveshaper envelope time (in conjunction with the downwards triangles at the bottom of the envelope window
• Feedback, to control the amount of feedback from both filters.
• Input Scale, to control the volume of the signal at the filter input. Because some of the filters have non-linear characteristics, scaling the input results in a slightly different tone. Controlling this with velocity can add expressivity to your presets.
• Output. to control the output of this filter that will be sent to the FX section.

When both filters are used, they are working in a parallel mode by default, with both filters output being sent to the effects section. However, it is possible to make a serial combination, where Filter1 is sent into Filter2, which is sent into the effects section:

• on the Filter1 page, set the velocity output curve to a flat zero, so that filter1 is not sent to the effects section.
• and on the Filter2 page, set the Feedback1 slider to a non-zero value

The available aftertouch curves are:

• AT cutoff, to control the filter cutoff.
• AT rez, to control the filter resonance.
• WS Amount, to control the amount of the morphable waveshaper effect.
• Feedback, to control the amount of feedback from both filters.