[sdiy] Minimoog EGs?

[Gene Stopp]

One thing I can tell you about the EG's in the Minimoog (at least the VCF
EG) is that when Attack = minimum (10ms) and the Decay = 1-2 seconds, the
amplitude of the envelope increases the more often it is triggered. It's as
if the new attack builds on top of the existing charge on the EG cap. I have
not run into another EG that does this, including the Moog 911 modular EG or
even the Voyager EG (although in the Voyager you can use velocity to boost
up the filter cutoff and get pretty much the same sound, since faster
playing is easily associated with harder keypresses). So this is one way
that the Voyager is *not* like the original!

I have patched the ARP 2600 to get the same effect, by using the keyboard
trigger to trigger the sample and hold, and sample the ADSR decay tail, and
add that to the filter cutoff.

Try this:

http://www.fantasyjackpalance.com/fjp/sound/synth/synthdata/16-minimoog/sche
matics000/minimoog-schematics-01.gif

Best Regards,

- Gene



-----Original Message-----
From: Michael Ruberto [mailto:frankentron at hotmail.com]
Sent: Thursday, February 06, 2003 10:42 AM
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] Minimoog EGs?




hi,

I am doing some comparisons on EG design and cannot find the schematic for 
the minimoog EGs. I would greatly appreciate it if somebody could point me 
in their direction since I am limited to dial-up and cannot do the power 
surfing I used to ;-)

has anybody here tried to duplicate the Mini's design? if so how would you 
characterize/describe the performance of it's EGs? how do they differ from 
most common ADSR circuits in musical qualities?

I am familiar with Mr. Bergfors' site and his excellent VCA comparison, 
maybe someone has done a similar comparison with EGs that I would find 
equally enlightening?

thanks!

Mike