Tutorial 11: Frequency Modulation Synthesis Basics

an FM basic patch seems to be quite easy to realize: the output of Osc2 (Modulator) is modulating the frequency of Osc1 (Carrier). but when you delve into it, you’ll see that the possibilities of FM are as vast as unpredictable. first, some terminology:
Operator is a combination of (usually) a sine oscillator, EG, VCA, output mixer, pitch modulator, and feedback destroyer.
Modulator is an Operator whose output modulates the frequency of a...
Carrier, an operator whose output goes to the Audio out (or, a filter, fx or whatsoever).
in Modular, the FmOperator can act as a Modulator as well as a Carrier; an EG is not included, but has to be connected to the EG input (which gives much more flexibility because you can use other mod sources as well [CtrlSeq, LFOs]). without a signal connected to the EG input, no sound will be heard.
further reading on FM: Gordon Reid’s SOS articles April and May 2000, Wikipedia.

for this patch, I’ve used 8 modules: besides MVC, 2xADSRs, esyncAdd2, a polyOut module and..

2x FM Operator

(OSC/Modulation) to get an overview, please see here. in this tutorial patch, the...

...4x1 switch

lets you decide whether Operator1 or Operator2 is the Carrier.


all coarse/fine/detune/FmA1/FmA2 settings of the Operators; Tmod + Lmod settings of the EGs (connected to the MVC’s velocity output).
not to forget time settings of the EGs.

further improvements:

use more FmOperators. use the DxRouter module. use seq modules instead of EGs. use other oscillators than the FmOperator module.

(patch with preset list)


tut01-basic mono patch
tut02-basic poly patch
tut03-basic Drum OSC patch
tut04-basic seq patch (async)
tut05-PS32 seq remote
tut06-basic seq patch (sync)
tut07-basic CWM morph patch
tut08-Modular as Fx device
tut09-subtractive synthesis basics
tut10-additive synthesis basics
tut11-FM synthesis basics
tut12-AM + RingMod synthesis basics
tut13-Phase modulation basics
tut14-KarplusStrong synthesis basics
tut15-Vector synthesis basics