MOTM

On 1/31/00, The Old Crow <oldcrow@...> wrote:
>
>  What would people think about an 8-stage EG with VC inputs based on a
>fast microcontroller with some 12/16-bit A/Ds, DACs and mux-s/h.  Good old
>PIC or Z8 single chip uP would be fairly simple to set up for ~2ms to 20s
>times without audible stepping given sufficient DAC resolution.
>
>  To make LEDheads happy, could have transition-state LED indicators for
>when one stage transited to the next.

It would HAVE to have a gate-detected indicator LED at least, and you
could flash that when it changes stages.  My latest (2 year old) idea
for a multi-stage EG consists of a series of 8 stages, with each stage
having 3 parameters:  ramp-to voltage, ramp rate and sustain switch.
The ramp-to voltage and ramp rate allow various timings and slopes, and
the sustain switch causes the processor to stick on that stage until
it detects a gate off.  I planned on using a PIC chip as a controller
for JH's VC EG idea using 2 NPN and 2 PNP transistors.  This seemed to
be easier than using a DAC.  I would use a window comparator to determine
when to change stages.  This is quite similar to the Roland MKS-50 EG,
only extended beyond ADSR.

I would LOVE for something like this to become a MOTM module!

I would envision a multi-stage EG as having 15 or more knobs and 
6 sustain switches; or 2 rotary encoders, 3 push-buttons and 
an LCD panel [add 8 jacks for voltage controll].  The buttons would 
be next/prev stage and sustain toggle.  You could also use the 
next/prev buttons as next/prev feature if you added several parameters
to each stage.

The 16 knob variant starts sounding like a sequencer doesn't it?
Either way, a PIC controller tied to an analog VC-EG stage would 
allow for voltage control without worrying about stepping.

Either way, I'm not against your idea, and in fact would like to 
have one.  You could add a gate delay, and a punch option to a
digital EG quite easily.  And for what it's worth, I vote for
using a PIC since I already have a PIC programmer.

Regards,

Roy Tate

Roy Tate
roytate@...