Emu XL-7 & MP-7 User's Group

On Sat, 1 May 2010, Atom Smasher wrote:

> i think i can do this with three cords instead of four, and less 
> fiddling to adjust it properly (assuming that a linear response is 
> desired)... it might be a few days before i can test it...
================

here it is... it can be done with just 3 cords and it's much easier than 
the previous method; little or no "fine tuning" required.

 1) MidiA  ->  Abs    +100
 2) DC     ->  Abs    -50
 3) Abs    -> *target*

this produces a "dip" at the center of the knob's range; invert the target 
polarity for a "peak" at the center of the knob's range.

the ratio between #1 & #2 determines the "center" and can be adjusted; eg 
a peak or dip can be produced at 25% or 75% by adjusting #2. i'd recommend 
leaving #1 at +100 for maximum range. the range is best reduced (if 
needed) in #3. to expand the output range add another cord and "4x Gain".

depending on exactly what you're doing it may be necessary to "normalize" 
either the center or ends of the knob's range; add another cord and assign 
DC to the target as needed.

either my math is off, or the the "Absolute Value" processor isn't quite 
working as advertised. i think that negative *outputs* are inverted 
*after* the inputs are summed but that part of my brain isn't fully 
working right now. in any case, the polarities of #1 & #2 don't matter, as 
long as one is positive and one is negative.

for more fun, use "LFO1+" or "LFO2+" (tri, sine) instead of a knob in #1 ;)

let us know if you come up with other variations on this. enjoy...


-- 
        ...atom

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