Message 2/6
Date: 18-Mar-04 @ 06:45 PM -
RE: What does the FM knob do exactly?
It uses the "value" of one oscillator to change the frequency of another osc. It'd be like using a hugely fast LFO to modulate pitch. There are many different algorithms to implementing this, so FM on the Virus sounds different (though similar) to the FM on my Nord.. The Virus FM seems to sound "good" in even divisions of 128 - 64, 76/32 sound a little buzzier, 16/48 etc sound grungier still.. The sync on the Virus nicely evens this out while maintaining pitch, but on the Nord, using sync and FM will throw you completely off pitch depending on the waveforms of the oscs.
I don't have enough technical background into why this is, just my observations.
Even though the FM might sound grungy, buzz, or downright crappy there're still uses for that type of timbre
I find that especially in a bassy sound you can use a tight LPF to just let a little of the grungy character into the sound while maintaining a pretty smooth bass element.
-Craig