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Ok you will have to visualise a graph.
Volume on the Y axis. Time on the X axis.
For the Amp attack envelope, the volume increases over time in a straight line. It is perfectly linear. Turning up the attack pot simply increases the time it takes for the volume to reach maximum.
When you modulate something you are basically making it increase/decrease/do something *over time*.
The decay works the same way but in reverse. Volume against Time. Linear downward slope.
There is only so much you can do with this 'linear fade in and out.' Pluck sounds for instance do not have a linear attack. It is very sudden - more like an inverse exponential attack and the decay is closer to exponential. It varies depending on the pluck sound but its definitely not linear.
In order to make the envelopes non linear you have to do a trick called recursive modulation. Basically, you set an amp envelope to modulate its own amp attack.
i.e. (Volume/Time)/Time
For the attack envelope the volume is increasing over time. For the decay envelope it is decreasing.
It is hard to visualise what this does to a graph but think about this example of recursion:
1! = 1
2! = 1 x 2 = 2
3! = 1 x 2 x 3 = 6 (or 2! x 3 = 6)
4! = 1 x 2 x 3 x 4 = 24 (or 3! x 4 = 24)
Can you see whats going on there? I am having trouble explaining how this would work as a graph without making things seem ridiculously complicated and I dont really want to start writing up recursive functions because thats really gay maths. And people come here to make music, not learn maths.
But with recursive modulation, values less than 1 result in concave graph shapes (In Howard Scarr's tutorial he calls this 'negative self modulation'). Recursive modulation with values greater than 1 result in convex graph shapes (again in Howard Scarr's tutorial he calls this 'positive self modulation'.
Using recursive modulation of envelopes can be used to literally change the slope of 'volume/time' on the amp envelope. This can be done with the filter envelope too but I find that even harder to explain.
The filter attack/decay envelopes are also linear'ish' by default btw.
Filter envelope = cutoff/time.
Recursively modulating the filter envelope = (cutoff/time)/time
The reason I find this fecking hard to explain is that the extent/speed (?) of the cutoff sweep is determined by the ENV amount and this will change the shape of the curve. ARGGGH. I hope you are getting closer to understanding this a bit better.
To get a visualisation of the Virus envelopes go here:
http://accessvirus.ashbysolutions.com/
Scroll down and compare it to the envelope of the Matrix 1000. Notice how the matrix attack envelope is slightly convex. You can mimic most classic analogue synth attack envelopes by positive self modulation of the Virus' amp attack envelope. However, some of the Oberheim ones - like the Matrix 1000 have really weird non linear attack envelopes, making them quite hard to clone.
Just take a look at it - you cant clone it *exactly* with recursive modulation. However, if you are totally obsessive about it, you could probably use an LFO shape or OSC waveform as a modulation envelope source and get closer to that kind of shape. But it would involve alot of trial and error, and to be honest, if you worked through that time instead, you could probably buy a Matrix 1000 at the end of it and save yourself the hassle.
Its easier to do this by ear if you have a reference sound you want to copy. After a while you dont even think about the math and just do it by ear. But it helps to understand whats going on so you know what direction you want to go in.
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About 'fatter' sounds. Fatter != more oscillators and more voices.
Some of the god damn hugest sounds ever made on a synthesizer consist of just 1 voice and 1 oscillator. Case in point - Roland TB-303 square wave bass. Absolutely *HUMONGOUS* sound. You can turn clubs inside out with a good clean square wave bass provided the amplitude is high enough.
The Minimoog is a 3 oscillator, 1 voice synth and it makes some of the most massive sounding leads and basses in existence.
More oscillators and more voices = potential for more harmonic complexity.
Amplitude + bass = bigger sounds.
The term fat probably comes from that wubbing kind of sound you get when you sweep an analogue oscillator with moderate to high resonance - as heard on trance classics like Binary Finary - 1998 with *that* Minimoog.
Oh yea, you can also clone the Minimoog's envelopes quite accurately using a Virus but it helps to have a visual plot of what it looks like. I think there are quite a few floating around on the internet for comparitive and cloning purposes. Failing that you could always ask a minimoog owner for a test tone...
EDIT: I made changes to that supersawish sound since theres yet more stuff I didnt like about it. Changes will be listed in a minute along with another sound clip of what it should sound like.
Last edited by Derivative on May-21-2006 at 23:13
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