Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

previous by date index next by date
previous in topic topic list  

Subject: Re: [PolySix] Osc Temperature Sensistivity

From: Bob Grieb <bobgrieb@yahoo.com>
Date: 2015-01-12

The PolySix writes out S&H voltages to the six voices in sequence.
0-5 channels are the six voices, and 6 and 7 of the 4051 mux are used
for anti-log tracking.   If the problem is with the first voice, maybe the
4051 demux is not switching fast enough, and the latched voltage is a little off?
Just an idea.

    Bob

From: "klosmon klosmon@sbcglobal.net [PolySix]" <PolySix@yahoogroups.com>
To: PolySix@yahoogroups.com
Sent: Sunday, January 11, 2015 1:46 PM
Subject: [PolySix] Osc Temperature Sensistivity

 
I've come across several P6 voice boards that have one oscillator (usually the first) that lags behind the others in coming into tune -- sometimes taking up to 20 minutes.
What is it in these oscillators that is temperature sensitive?  Or is this actually a temperature issue, or something else?
The board I'm currently working on has had all the caps and semiconductors on the first oscillator swapped out, and the oscillator will tune to the others after a 20 minute warmup;  but I'm curious as to why only one oscillator would behave this way.
Thanks.
~GMM