S213 Morphing VCF

Product Description

 

(This module is included in the System B)

 

The S213 is a multislope, multimode voltage controlled filter that has the ability to smoothly morph from low pass to high pass modes in three different ways as a side effect of the slope (roll-off) chosen.

 

12db/oct slope: The filter will morph from low pass to notch to high pass. This is similar to how the Oberheim(TM) SEM filter works.

 

24db/oct slope: The filter will morph from low pass to peak to high pass.

 

36db/oct slope: The filter will morph from low pass to notch inside peak to high pass.

 

The cutoff has two patch points inputs. One labeled Cut CV and the other is Frq CV. Cut CV is meant for key tracking. So it makes sense to connect it to note output (0.1V/oct) like from a MIDI to CV module or from a sequencer. The Frq CV is meant for modulation and has an attenuator knob attached to it.

 

Knob/CV control is available for most of the parameters which are mostly self explanatory. Separate inputs for low pass (In LP) and high pass (In HP) is provided. In LP is normaled to In HP*.

 

The S213 is equipped with dedicated overdrive Knob/CV controls. The Soft/Fold switch affects the type of overdrive used. Soft will give a familiar but still aggressive flavor when the resonance is cranked up. Fold is a rather unique and and extremely aggressive mode, specially with high drive and resonance.

 

As with most filter overdrive. The overdrive amount is more or less sensitive to the loudness of the input signal. A good input signal would be from -1V to 1V (0dbFS), so connecting the filter directly to an oscillator and placing the Lev knob at 12:00 o’clock and tweaking the Lev from there is a good idea. However, if the input signal is low, the Drive controls will automatically try to lift the gain to compensate. Still if the input signal is really too low, the filter may not get to saturation level, and hence no overdrive will occur!!. On the flip side, if the input loudness was too high, the filter may be over driven even when the Drive is at minimum, this can specially happen when resonance is very high.

 

Usage ideas

1.Try to modulating the filter cutoff (Frq CV) and the Morph CV with the same CV source. You’ll some interesting effects there.

2. In 36db mode, put the morph at 12:00 o’clock. using high resonance, modulate the cutoff with some base to mid range input audio. It gives a rather unique and hollow flavor.

 

*If In HP is not connected, it will take its input from In LP.