> From: ktfiz
>
> Paul, I think you are on to something!
>
> The PULSE WIDTH MOD slider does affect this. When the PULSE
> WIDTH MOD slider is in the center position the modulation
> goes away. As I move the slider down it increases the
> modulation I hear until it is fully on at the bottom.
> However, as I move the slider up just past center it goes to
> fully on. I assume that is a faulty or dirty PULSE MOD WIDTH slider?
>
> I also realized that I get the same effect on OSC 2 as well.
> However the PULSE WIDTH MOD slider does slowly increase the
> modulation I hear from center to the bottom and from center
> to the top. So, it seems at least that the bi-polar slider
> works correctly on OSC 2.
>
> So, I guess my question now is...
>
> In a perfectly functioning Polaris, if the PULSE WIDTH is all
> the way at the bottom and you move the PULSE WIDTH MOD slider
> either up or down away from center, should you hear this
> modulation? So in order to completely turn off an oscillator,
> PULSE WIDTH needs to be at "0" and PULSE WIDTH MOD needs to
> be at center?

If the width is at zero, you'll hear half the bipolar sine wave modulation
and all the unipolar square wave modulation. If the width is at 100%, you'll
hear the other half of the bipolar sine wave modulation and none of the
square wave modulation. If you dial in enough width that you don't clip the
modulation, you'll hear all the modulation.

> If so, then I am only looking at a faulty bi-polar slider.

I think it's more likely to be a bad 4051 chip (Z3) than a faulty slider. If
they're socketed, you could try swapping Z3 and Z4 to see if the problem
moves to different sliders.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...