F I LT E R
FILTER knob
Adjusts the center frequency of the filter
(Full cutoff is not possible)
FILTER switch
Sets the frequency range of the filter and
enables filter self-oscillation
The Grendel Drone Commander filter can self-
oscillate, adding complexity to the tone.
Self-oscillation of the filter happens when the
FILTER switch is down, and the FILTER knob is
set anywhere from fully counter-clockwise to
mid-way.
The self-oscillation gets stronger as the filter
is tuned to lower frequencies. It gives an
overdriven quality to the sound.
The self-oscillation can alter the sound of OSC
1 and OSC 2, by emphasizing their harmonics.
As the LFO sweeps the filter, the self-
oscillations can stair-step through a cascade
of overtones and subharmonics from OSC 1
and OSC 2.
To use the pure sound of the filter’s self-
oscillation, “dead-patch” the
Audio IN
jack.
This mutes OSC 1 and OSC 2.
Filter Tips: Self-oscillation
Filter Drive Trim**
Adjusts the amount of filter overdrive
**Normally there is no reason to adjust this
setting, but if you like tweaking things, you
can try it. To adjust this control, insert a 2mm
at blade screwdriver through the port. The
factory setting is 50%.
7
High Range
Low Range
(self-oscillation)
Low
Middle
High
(self-oscillation)
The
Filter CV
input lets you modulate the filter from an external LFO, analog
sequencer, or envelope generator. The maximum input voltage range is -10
to +10 volts. The response is not 1 volt/octave. The depth of modulation
may be light to moderate, depending on the output voltage range of the
device that is patched to Filter CV.
Grendel Drone Commander
Classic Pedal
