Alesis micron User Manual

 

FM Amount 
FM, or “frequency modulation,” allows you to use one oscillator to 
control the frequency of another.  Set the percentage by which the 
target oscillator’s frequency is affected by the master oscillator’s 
waveform.   
 
FM Type 
 
A.  Linear FM types 
lin 2 > 1   
Oscillator 2 is added to the phase of oscillator 1.  Linear FM is the 
style used by typical FM music synthesizers.  Modulating a sine 
wave with another, higher-frequency sine wave produces a 
fundamental frequency with a variety of overtones, and this can be 
used to reproduce the sounds of many physical musical 
instruments.   
 

 

lin 2+3 > 1 
Oscillators 2 and 3 are added to the phase of oscillator 1. 
 
lin 3 > 2 > 1 

Oscillator 3 is added to the phase of oscillator 2.  The resultant 
waveform is added to the phase of oscillator 1. 
 
With linear FM, the FM Amount controls the “modulation index”, 
with a level of 100% providing an index of 32.   
 
B.  Exponential FM types 
exp 2 > 1   
Oscillator 2 modulates the pitch of oscillator 1. 
 
exp 3 > 2 > 1 

 

Oscillator 3 modulates the pitch of oscillator 2.  The resultant 
waveform modulates the pitch of oscillator 1. 
 
With exponential FM, the FM Amount controls the range of pitch 
modulation, with a level of 100% driving the pitch up and down a 
full six octaves.