uFSK
Frequency shift keying is a method of digital data transmission by frequency modulation of a carrier to represent ones and zeros. Here we are switching between two different oscillators using a third signal. Typically the modulator is some sort of square wave but I extended the concept to allow for any type of 0-1 modulator. The modulator varies the mix between oscillator A and B using a crossfade node. I suppose it’s really a sort of frequency modulation. Depending on the oscillator waveforms, their relative frequency and the waveform and frequency of the modulator you can generate some very harmonically rich outputs. It uses the built-in oscillator node so the fundamental waveforms are de-aliased. The waveform type and shape can be selected. There are two 1 per octave inputs which can be linked using the toggle. The input below the toggle changes the toggle’s state. There are coarse and fine frequency controls, and an output level control for each oscillator. The fsk modulator can be either external, or a square wave derived from oscillator A, controlled by the int/ext toggle. Again, the input below the toggle can be used to change it’s state. There is also a sync input for the two oscillators. There is the switched output and ring modulation of each oscillator with the fsk signal and with each other. The fsk signal is low-pass filtered at 10kHz to reduce aliasing.
I/O
| Input | Signal Range | Notes |
|---|---|---|
 |
1 per octave |
two inputs - can be linked |
 |
0-1 modulation |
modulation signal is typically at audio frequencies |
 |
gate |
oscillator sync input |
| Output | Signal Range | Notes |
|---|---|---|
 |
0-1 audio |
primary mixed signal output |
 |
A * fsk ring mod |
|
 |
B * fsk ring mod |
|
 |
A * B ring mod |
Controls
| Control | Function | Notes |
|---|---|---|
 |
link toggle |
on (red) links 1 per octave inputs together - input changes toggle state |
 |
coarse frequency control |
50% is concert pitch |
 |
fine frequency control |
50% is concert pitch |
 |
selects waveform |
|
 |
wave shape control |
wave shape for square and ramp waves |
 |
selects external or internal fsk source |
on (red) for external fsk source - input changes toggle state |
Displays
none
Version History
| Revision | File | Date | Notes |
|---|---|---|---|
| 2.2 | uFSK oscillator V2.2.audulus (39.4 KB) | 05/27/2018 | initial upload to new forum |
Demos
| Revision | File | Date | Notes |
|---|---|---|---|
| 1.0 | uFSK Oscillator V2.2 demo.audulus (1.5 MB) | 05/27/2018 | Runs on iPad Air 2. I had the triggers mapped to my Korg nanoPad. |
| 3.0 | uFSK Oscillator V2.2 demo III.audulus (2.8 MB) | 05/27/2018 | runs at 45% on my Mac |
