Modulation Mix - Moog Minimoog Operation Manual

controllers
This section will demonstrate the use of the controls located to the left of the Oscillator Bank
(used in tuning and setting up a sound), as well as the keyboard and the manual controls on
the panel to its left (used during performance). All of these controls have an effect on the os-
cillators' pitches, while the Modulation Mix and keyboard may also be used to control the fil-
ter.

modulation mix

Oscillator 3, unlike Oscillators 1 and 2, is available as a control signal in addition to function-
ing as an audio signal. As a control signal, it may be mixed with the output of the Noise
Source using the MODULATION MIX control (3) and introduced whenever the performer
wishes, using the MODULATION wheel (29). The procedure described below will familiar-
ize you with the use of the Modulation Mix in controlling the pitch of Oscillator 1:
1. Turn off switch (B), so that the pitch of Oscillator 3 is not affected by the keyboard.
2. Turn off switch (G) and turn on switch (C). Now you are hearing Oscillator 1, but not
Oscillator 3, when a key is depressed.
3. Set Oscillator 3's RANGE switch (9) to the LO position, its FREQUENCY control (10)
to mid (0) position, and its WAVEFORM switch (11) to the triangular (extreme left) set-
ting. This produces a very low frequency triangular waveform which oscillates only a
few times a second.
4. Set the MODULATION MIX control to 0, so that its signal is that of Oscillator 3. Turn
on the OSCILLATOR MODULATION SWITCH (A). This switch directs the Modula-
tion Mix signal to control the oscillators' pitches.
5. The slowly varying output voltage of Oscillator 3 is now going through the MODULA-
TION wheel (29) at the left of the keyboard, and from there may be applied to periodi-
cally change the oscillators' pitches (we will hear its effect on Oscillator 1). The MODU-
LATION wheel is in effect a level control for the Modulation Mix. Slowly move the
MODULATION wheel back and forth with your left hand while holding down a key with
your right hand. The position of the Modulation wheel will determine the amount of
variation you hear in the pitch of Oscillator 1.
6. Change the setting of Oscillator 3's FREQUENCY control and notice the resulting in-
crease and decrease in the speed of the modulation
7. Change the setting of Oscillator 3's WAVEFORM switch and you will notice the change
in the shape of the modulation. You should actually be able to hear the contours of the
different waveforms − the alternation of high and low tones in the square wave, the re-
peated upward glissandi of the sawtooth, etc.
8. The setting of the MODULATION MIX control determines the proportions of the mix-
ture of Oscillator 3 and Noise Source. As you slowly turn this control clockwise, you will
hear less periodic modulation and more random modulation.