User Manual
15
MODIFIERS
The MODIFIERS Panel contains three separate sections: FILTE R, FILTER CONTOUR, and LOUDNESS
CONTOUR. The Filter selectively modies the harmonic content of the sound. The Contour controls,
also known as Envelope Generators, provide a control signal that changes over time. The FILTER
CONTOUR controls the lter’s Cutoff Frequency over time. The LOUDNESS CONTOUR controls the
output volume level over time.
FILTER CONTROLS
CUTOFF FREQUENCY KNOB
The 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 lter Cutoff Frequency is
reduced by the lter at a rate of 24dB/Octave. Harmonic
content, or sound, below the lter Cutoff Frequency will
freely pass unaffected. This is the foundation of subtractive
analog synthesis. While the Cutoff Frequency can be set
manually using the CUTOFF FREQUENCY knob, the value
is also affected by the KEYBOARD CONTROL switches,
FILTER MODULATION switch, FILTER CONTOUR controls
and the AMOUNT OF CONTOUR knob, which are discussed below. When closing the lter by
lowering the CUTOFF FREQUENCY, the sound will be perceived as growing darker, while increasing
the Filter’s CUTOFF 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 lter’s Cutoff
Frequency. By turning the EMPHASIS control up and lowering the Filter CUTOFF 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 dened below.
FILTER MODULATION SWITCH
When this switch is On, the Filter Cutoff Frequency can be modulated by the Noise Generator, Filter
Contour, Oscillator 3, and the LFO (Low Frequency Oscillator). The modulation source and amount
are dened by the CONTROLLERS settings and the MODULATION WHEEL position.
KEYBOARD CONTROL (1 & 2) SWITCHES
The KEYBOARD CONTROL switches allow the note played on the keyboard of the Minimoog Model
D to affect the Filter Cutoff Frequency, a process also known as key tracking. This allows notes
played higher on the keyboard to have brighter sound. KEYBOARD CONTROL 1 provides 1/3 of the
total amount of available key tracking. KEYBOARD CONTROL 2 provides 2/3 of the total amount of
available key tracking. By using both switches together, the full amount of available key tracking (1/3 +
2/3 = 1) is applied.