Wednesday 21 February 2007

FM Part 3


Making a simple FM synth, part 3: Playing with frequencies

Watch the video




Notes
  • (2:30) MINUS frequencies??? This makes sense... at NAMM this year, the Technicians of the Museum of Techno spoke to Cynthia Webster of Cyndustries.com, who makes an analog FM oscillator called the Zeroscillator. She's very proud that the oscillator is "through-zero", so if you tell it to play a negative frequency, it'll cycle through its waveform in reverse direction. I'm going to get a Reaktor oscilloscope going, I think, to investigate this... I'd like to see what it looks like.
  • Watch the modulator's A input value going up and down... it feels like larger values, more frequency modulation, make for brighter sounds.

2 comments:

Leech Ernowetz said...

Hello Dave,

Thanks for the helpful videos! I am having problems with the note read out part in this video. Taking the output from note-pitch into the exp(f) module and then out to the "note readout) module, i get a small x on the input of the readout. I am pretty sure i am following the instructions correctly. I can get the note values directly from notepitch, but when passing through the converter module i get the x! Why is this happening? Is this a mono/polyphonic thing? I have no lcue, any info you could give would help me understand this more. Thanks!

Leech.

Museum of Techno said...

I bet that's because your instrument is polyphonic (set for more than one voice) whereas mine is monophonic (one voice only). If you try to feed a polyphonic signal into a monophonic module (one which can only process or display a single stream of numbers) you'll see one of those little X's - try turning down the Voices value in the Instrument header bar to 1, and the X should disappear.