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

--- In chromapolaris@yahoogroups.com, "Paul D. DeRocco" <pderocco@...> wrote:

> The sweep signal is a pure software signal. The only way it can manifest
> itself in the hardware is if it is used to modulate one of the six control
> voltages that go to the channel. One of the things it can modulate is pulse
> width. Therefore, I suspect there is some interaction between the PULSE
> WIDTH slider and the PULSE WIDTH MOD slider. It could be a short somewhere,
> or a broken ground, or a bad 4051 multiplexer on the panel.
>
> --
>
> Ciao, Paul D. DeRocco
> Paul mailto:pderocco@...
>