Message 18/32
Date: 25-Sep-02 @ 11:00 PM -
RE: virus filter
Yes I dont know how the nova's filter behave but I do know how the Virus and the JP 8080 behaves.
The filters on these synths actually lose frequency or signal when your at 24 db mode. Now if you have the filter wide open with no resonance both the Jp 8080 and the Virus will see no loss in signal or freq quality no matter if its 12 or 24 db mode. On the Jp 8080 if you turn up the res with the filter wide open the waveform will start to atenuate and you will also hear the Q gain or res gain if you like. On the Virus if the filter is wide open and you turn up the q gain it will not atenuate the waveform but instead act more like a volume control. The more res you give the quiter the waveform gets.
Now if you have the filter half way open with no resonance and you switch from 12 db mode to 24 db mode you will notice that in 24 db mode on both the Virus and the Jp 8080 the waveform sounds alittle quiter and as well less quality meaning the 24 db mode is not letting all the signal out of the waveform. The waveform in 24 db mode sounds darker in tone in 12 db mode the waveform will sound brighter.
Now add some resonance and you will here the attenuation as well the Q gain. Both synth will sound more and more raspier as you add more Q. The difference is on 24 db mode the JP 8080 goes to self oscillation becuase the Q gain is greater than the cutoff slope. So when you move the cut off with full gain on the JP at 24 db mode it will sound like a whistle. This is the full feedback of the Q. I can say even though the JP 8080 can self oscillate it is still not perfect oscillation becuase you can still hear very little of the waveform. Its just in the background very quitely. But its close enough to be considered self osc.
The Virus with full q wont self osc becuase its filter cutoff is greater then the Q factor. Yes you can create a self osc like sound on the Virus if you programe it right but all it is is shapeing the waveform with the cut off slope to fit that self osc quality of sound. which is totaly different then that of what the JP 8080 does.
I admit im no signal expert but I can tell you what my ears are hearing. And this is how those filters sound to me.