self oscillating?

[eternalYouth]

ok. im sure all of you are familiar with the c127 sound when you want to create a new noise.... has anyone else noticed that the initial setting for the osc. mixer is set to either one or two and not centered..?. and when you center it the noise starts to fade in and out... almost like modulation...

is this called self oscillation? if not what exactly is causing this effect and how the hell can i fix it?! :(

thanks in advance.

-justin

[ben crosland]

This is exactly what you should expect. It's what happens when two sound sources (ie 2 oscillators) are playing at a similar pitch, but slightly detuned. The frequencies of the two waveforms are not the same, therefore don't line up with each other, which is what causes the inter-modulation.

Adjusting Detune will change the speed of the modulation. If you want to get rid of it, you need to turn Osc2 Detune to 0. This will stop the detuning modulation, but you will still get phasing, because the two oscillators' waveforms (which are both Saw in the Start and -INIT- patches) don't start at exactly the same point in the cycle. To cancel this, you need to set PhaseInit (Osc Edit Menu) to something other than 0. This forces the oscillators to start at a particular point in the cycle at Key On.

Bear in mind that removing all of this inter-modulation (particularly the Detune) will remove any 'analogue' warmth from the sound. I guess this is what you're trying to achieve though?

[ben crosland]

Oh, and no it isn't 'self-oscillation'. That is the term used to describe the effect of the new 'moog' filter in OS6.5 which generates an oscillator-like tone when Resonance set high enough, even with no input at the filter stage.

[eternalYouth]

thanks for the quick response!!

and yes i was going for the grimey blips and bangs.. this works out perfectly! now with some harsh saturation im sure to drive the neighbors' dog up a wall!! :)

thanks!!

[scottyp]

mmmm.... saturation

[Juho L]

Originally Posted by scottyp

mmmm.... saturation

With Homer Simpson voice?

[scottyp]

of course!!!

I think my favorite is "mmmmm... 64 slices of American Cheese"!