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

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Subject: Re: [PolySix] RE: Lots of pots not working

From: Bob Grieb <bobgrieb@yahoo.com>
Date: 2014-01-06

Hi Josh,

    Maybe we should take this off-line so that others don't have to get all of the emails? If you want, you can email me at rlgrieb  then the number one, then "at" sign, then verizon.net

    From your measurements, it seems that the analog muxing of the front panel controls is working.  Sounds like maybe the DAC is toast.  Does the voltage at IC27 pin 1 (not labeled on the schem) ever change, either in test or manual mode?

    Thanks

     Bob


From: "josh.nursing@gmail.com" <josh.nursing@gmail.com>
To: PolySix@yahoogroups.com
Sent: Monday, January 6, 2014 9:40 AM
Subject: [PolySix] RE: Lots of pots not working, MG, VCF, EG.

 
Starting with all pots at Center position, I do get 0V on the data pin.

All pots to Min: I get -4.35V
All pots to Max, I get 4.35V.

Since Res is the only pot which works the other way round, I get this is ok?

Avg sweep for the Cutoff pot, I get a variation from -4.35V to -3.73V...

I was using the Res line on KLM-367 as it seems it is the easiest one to verify, but I agree, I should focus where the issue seems to be and if it's the DAC, investigate there. Also agree with the need for a scope...

Yash