Do G2 Filters Self Oscillate?

skylab001 · Posted: Wed Sep 28, 2005 1:36 pm Post subject: Do G2 Filters Self Oscillate?

I am curious if the Filters that are part of the G2 Self Oscillate like real analog filters? I am really looking to creating all sorts of different percussive analog sounds so this would be a benefit.

I have been considering a Nord G2 engine or a Doepfer a-100. I have been using Reaktor 4, but honestly, it is very powerful, but since it goes so deep(building the modules themselves) it takes a bit longer to create a patch. I breifly tryed a Nord modular G1 and it seemed a bit easier having the pre-built modules. The nord looks good due to price and the patch saving functionality, but not sure how it compares to real analog stuff(ie. do the modules really behave like analog modules, and does it sound the part?)

I would use the G2 engine with my Keystation Pro88 controller. Does anybody else have this setup or similiar and like it?

mosc · Posted: Wed Sep 28, 2005 1:58 pm Post subject:

I have an original Moog Modular. The G2 has great difficulty replicating the hum, noise and oscillator feedthough. Other than that, it sounds great. Laughing

Download the demo from the Clavia site and you'll get a good feel for what the G2 is all about.

I use the G2 for everything analog. The Moog is better for teaching an introduction to analog modular synthesis because it is all in front and visable.

A real analog synth has potentiometers for controls. These are continuous. The G2's knobs and those of MIDI controllers are in 128 discrete steps. In some cases, this is objectionalbe but there are ways to work around it. .

blue hell · Posted: Wed Sep 28, 2005 2:16 pm Post subject:

Welcome skylab,

yes hte filters can self oscillate, but unlike an analogue system they will not oscillate without excitaton. Once they oscillate the excitation is no longer needed and oscillation can continue forever. Now analog filters need excitation as well to oscillate, but their own internal noise will be sufficient for this.

You were speaking of using (near) self oscillating filters for drum sounds, and so you'll probably want to excite the filters with some signal (like an impulse or a noise burst), in that case the sef oscillaton will work as expected.

And when this behaviour is a problem you can always inject a little noise into the filter your self.

When the demo sftware wont run on your computer you cam always listen to some tracks qvailable on this forum (and on the Clavia site are some demos as well).

ian-s · Posted: Wed Sep 28, 2005 2:21 pm Post subject:

Filter self oscillation is caused by very high gain in the resonance feedback path. In the analog domain, there is always small amounts of signal (background noise) to start the oscillation. On the Nord, you need to patch this small amount of signal into the input, the end result behaves like an analog filter with several different options regarding frequency/gain relationships. Some real analog filters stop oscillating below a certain frequency, which makes them less useful for kick drums etc.
You can also just use a sine oscillator, you can squeeze more than 100 into one slot using both VA and FX areas.

Edit: Sorry Jan, looks like we just said the same thing.

skylab001 · Posted: Wed Sep 28, 2005 2:34 pm Post subject:

wow thanks guys for the quick feedback on this subject! I'm glad to know are here. I just downloaded the demo and am going to try it out......one question though....wouldn't the actual G2 hardware sound different than my computer generating the sound. Anyway I'm going to give it a try.

ian-s · Posted: Wed Sep 28, 2005 2:56 pm Post subject:

blue hell · Posted: Wed Sep 28, 2005 3:52 pm Post subject:

Ian we agree again :-)

Aditionally there is a bug in the ClkDiv module in the demo version, which may cause certain patches to sound weird. See http://electro-music.com/forum/topic-6435.html