<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>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. </div><div><br></div><div><a href="http://joachim.milson.free.fr/cs80/master-boards.html">http://joachim.milson.free.fr/cs80/master-boards.html</a></div><div><br></div><div>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. </div><div><br></div><div><br></div><div><br>On Jan 17, 2017, at 2:58 PM, Mattias Rickardsson <<a href="mailto:mr@analogue.org">mr@analogue.org</a>> wrote:<br><br></div><blockquote type="cite"><div><span>Yamaha's envelope chips are odd in the way they use an extra VCA chip</span><br><span>just to implement the envelope itself. I'd expect them (all of the</span><br><span>Yamaha IG chips) to be very simple inside. The envelope chip probably</span><br><span>just consists of the little logic state machine taking care of the</span><br><span>Attack/Decay/Release envelope phases, and routing the input CVs</span><br><span>correspondingly, letting the external extra VCA chip do the slopes.</span><br><span>Maybe this chip is already analysed and copied to standard components</span><br><span>of breadboard?</span><br><span></span><br><span>/mr</span><br><span></span><br><span></span><br><span>On 17 January 2017 at 14:05, Nicholas Keller <<a href="mailto:niroke@tampabay.rr.com">niroke@tampabay.rr.com</a>> wrote:</span><br><blockquote type="cite"><span>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?</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Thanks</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>Nick</span><br></blockquote><blockquote type="cite"><span></span><br></blockquote><blockquote type="cite"><span>_______________________________________________</span><br></blockquote><blockquote type="cite"><span>Synth-diy mailing list</span><br></blockquote><blockquote type="cite"><span><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a></span><br></blockquote><blockquote type="cite"><span><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></span><br></blockquote></div></blockquote></body></html>