Moog MINIMOOG MODEL D - Filter Controls

29 | Modifiers
FILTER CONTROLS
CUTOFF FREQUENCY KNOB
Minimoog Model D is equipped with a traditional Moog
Ladder Filter with 10Hz-32kHz frequency response. This
is a critical component to the thick, punchy, and powerful
Minimoog Model D sound. When a note is played, harmonic
content occurring above the filter Cuto Frequency is
reduced by the filter at a rate of 24dB/Octave. Harmonic
content, or sound, below the filter Cuto Frequency will
freely pass unaected.
This is the foundation of subtractive analog synthesis.
While the Cuto Frequency can be set manually using the
Cuto Frequency knob, the value is also aected by the
Keyboard Control switches, Filter Modulation switch, Filter
Contour controls, and the Amount of Contour knob, which
are discussed below. When closing the filter by lowering the
Cuto Frequency, the sound will be perceived as growing
darker, while increasing the Filter’s Cuto Frequency will
create a progressively brighter sound.
EMPHASIS KNOB
Often referred to as resonance, the Emphasis knob takes a
portion of the output of the Filter and sends it back to the
input of the Filter, creating a resonance peak that occurs at
the Filter’s Cuto Frequency. By turning the Emphasis control
up and lowering the Filter Cuto Frequency, the Filter can
be coaxed into a self-oscillating state, acting as a sine-wave
oscillator whose pitch can be controlled or played via the
keyboard by using the Keyboard Control switches defined
below.
FILTER MODULATION SWITCH
When this switch is on, the Filter Cuto Frequency can be
modulated by the Noise Generator, Filter Contour, Oscillator
3, and LFO (Low Frequency Oscillator). The modulation
source and amount are defined by the CONTROLLERS
settings and the Modulation Wheel position.