[sdiy] Yamaha IG00159 internals

Nicholas Keller niroke at tampabay.rr.com
Tue Jan 17 22:49:47 CET 2017


That's what I was hoping.  There are some interesting notes on this page about the unique curve to the envelopes, but I don't understand most of it. 

http://joachim.milson.free.fr/cs80/master-boards.html

The PDF that was posted earlier in this thread seems to confirm your suspicions about the contents of the chip, but I don't know how to create the sequential switch. 



> On Jan 17, 2017, at 2:58 PM, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> Yamaha's envelope chips are odd in the way they use an extra VCA chip
> just to implement the envelope itself. I'd expect them (all of the
> Yamaha IG chips) to be very simple inside. The envelope chip probably
> just consists of the little logic state machine taking care of the
> Attack/Decay/Release envelope phases, and routing the input CVs
> correspondingly, letting the external extra VCA chip do the slopes.
> Maybe this chip is already analysed and copied to standard components
> of breadboard?
> 
> /mr
> 
> 
>> On 17 January 2017 at 14:05, Nicholas Keller <niroke at tampabay.rr.com> wrote:
>> Does anyone know of an internal diagram for the IG00159 amp EG chip?  Or has someone made a stand-in circuit for the chip alone?
>> 
>> Thanks
>> 
>> Nick
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20170117/ca1eb67a/attachment.htm>


More information about the Synth-diy mailing list