Author 
Envelope Generator CV over Log/exp ? 
Jaypee 
I have 3 Functions and 1 Contour in my racks
They would be perfect if I could control the lin/exp curve.
So I'm looking for some options...with control over exp/lin and A and D.
These are the first modules on to my mind, if I'm correct:
Rampage Befaco
Mini Slew Steady State Fate
Anything else worth checking?
Cheers,
J. 

The Junglechrist 
You can actualy patch that control if you take the output of your Function / Contour to a VCA and back into its control input. If you go negative it will become exponential and positive will go log, so depending on what control signal you feed into it it can go from one to the other. 

Jaypee 
Oh! That IS GREAT!
Merci The Junglechrist! 

Graham Hinton 
The Junglechrist wrote:  You can actualy patch that control if you take the output of your Function / Contour to a VCA and back into its control input. If you go negative it will become exponential and positive will go log, so depending on what control signal you feed into it it can go from one to the other. 
Calling log the opposite of exp is a mistake started by someone who doesn't understand maths. The opposite of exponential is inverse exponential. You can't make a logarithmic curve. Think about it, what is the log of 0? 

Jaypee 
Graham,
I read several posts on diff threads about lin/exp curves etc but I don't have the maths knowledge to understand.
I was hoping you came into this thread.
So let me, rephrase my question: any way to go from a curve to another with a Function and couple of utilities (polarizer, vca etc) for example?
Many thanks for your posts,
J. 

Graham Hinton 
Jaypee wrote:  So let me, rephrase my question: any way to go from a curve to another with a Function and couple of utilities (polarizer, vca etc) for example?

You can change the shape of any waveform that is based on charging a capacitor that has voltage control of the rate by feeding back its output to the control. Sometimes that is built in to the module. If the feedback is positive the slope will get steeper the higher the voltage, if the feedback is negative the slope will get less steep the higher the voltage. It's that simple. This applies to VCOs and LFOs as well as envelopes, but it will alter the frequency or time as well.
A VCA will give you control of shape as long as it is DC coupled, but it won't change between positive and negative without more adders and inverters. It is easier to use a "four quadrant multiplier" which is what most nontransformer ring modulators are. Put the signal to be fed back in one input and a bipolar DC control voltage in the other, then patch the output to the rate control. 

The Junglechrist 
Graham Hinton wrote:  The Junglechrist wrote:  You can actualy patch that control if you take the output of your Function / Contour to a VCA and back into its control input. If you go negative it will become exponential and positive will go log, so depending on what control signal you feed into it it can go from one to the other. 
Calling log the opposite of exp is a mistake started by someone who doesn't understand maths. The opposite of exponential is inverse exponential. You can't make a logarithmic curve. Think about it, what is the log of 0? 
Yup sorry about that i'm indeed not good at math. That is what I had the feeling it was doing, in term of sounds as it compared to the result of the log setting on Maths (the module). 
