Moog Music MF-103 12-Stage Phaser - Manual (Page 8)

instrument signal are alternately emphasized and then attenuated.
Figure 9 – How the phaser frequency response changes as the SWEEP is varied.
The phaser parameters are independent of one another. This means that you
can set them in any combination that you wish. There is no such thing as a
“wrong” combination of settings of the MF-103, so you can experiment all you
like to find new, exciting effects for your music.
THE LFO (LOW FREQUENCY OSCILLATOR)
LFO stands for Low Frequency Oscillator. LFO’s are generally used to create
slow modulations such as vibrato and tremelo in electronic music equipment.
The LFO in your MF-103 is an extremely wide-range voltage-controlled oscillator
which modulates the phaser’s Sweep parameter. This enables you to vary the
Sweep automatically at speeds from one cycle every 100 seconds (0.01 Hz), to
250 times a second (250 Hz). At the slowest speeds, the change is so subtle and
gradual that it is barely perceptible. At speeds of, say 0.1 Hz to 2 Hz, you get a
wide range of classic “whooshing” phaser effects. From about 2 Hz to 10 Hz,
you’ll find the vibrato and tremelo effects. At frequencies above 20 Hz, the
variation is in the audio frequency range and you get effects similar to ring
modulation.
The RATE control varies the LFO speed over a 250:1 range. When the left switch
is on LO, the RATE control varies the speed from 0.01Hz to 2.5 Hz; when the left
switch is on HI, the RATE control varies the speed from 1Hz to 250 Hz. The LFO
indicator gives a visual indication of the LFO speed.
The AMOUNT control varies the depth of phaser modulation, from barely
perceptible to the full sweep range of the phaser.
THE AUDIO LEVEL CONTROLS
The DRIVE control adjusts the signal level at the phaser circuit input. With this
control you can set the right input level for virtually any instrument or line-level
signal source. Turn this control counterclockwise for strong input signals, and
clockwise for weaker sound sources.
The LEVEL light tells how strong the input signal is after being adjusted by the
DRIVE control. As the signal level increases, the light goes from off, to green, to