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Poly 800 (MK I) tuning drift

2011-07-11 by honod3k

After being on for over an hour (w/ power adapter, not batteries) my Poly went so far flat that I had to move the 'Tune' slider all the way to the right. Soon even that wasn't enough. Has some component failed or are there pots I can adjust to increase the range of the 'Tune' slider?

Re: [korgpolyex] Poly 800 (MK I) tuning drift

2011-07-11 by Michael Hawkins

The master TG clock is not particularly susceptible to power supply drift but nevertheless, I would check your power supply for drift first.

Then, if the power rails are not drifting then I would next check that the voltages are stable coming

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from:

Tune - R159
Vibrato - R162
Bend - R161

Use the schematics in the Poly-800 files section for detail.

Then, if they remain stable, I would start checking the master oscillator itself.

But until you exclude the above. I would not go poking around the master oscillator.

Mike

From: honod3k <cbluff@...>
To: korgpolyex@yahoogroups.com
Sent: Mon, July 11, 2011 7:30:06 AM
Subject: [korgpolyex] Poly 800 (MK I) tuning drift

After being on for over an hour (w/ power adapter, not batteries) my Poly went so far flat that I had to move the 'Tune' slider all the way to the right. Soon even that wasn't enough. Has some component failed or are there pots I can adjust to increase the range of the 'Tune' slider?

Re: [korgpolyex] Poly 800 (MK I) tuning drift

2011-07-11 by billmeirelles@uol.com.br

Yep, check the service manual, there is a VR for tune.

Em 11/07/2011 08:30, honod3k < cbluff@... > escreveu:

After being on for over an hour (w/ power adapter, not batteries) my Poly went so far flat that I had to move the 'Tune' slider all the way to the right. Soon even that wasn't enough. Has some component failed or are there pots I can adjust to increase the range of the 'Tune' slider?