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Subject: Re: [chromapolaris] Osc 2 mod issues on just one voice

From: Eric Frampton <eric@...>
Date: 2013-02-25

Yep, I've done the whole service routine, and it all calibrated up just fine.

Unfortunately, I don't have any spare ADC0804's to toss in there. Where would I find one now?

e

On Feb 25, 2013, at 7:41 AM, sukhoy27@... wrote:

Hi , did you try to follow the test as indicated in the Service Manual , just like 
Lower Function D , 4 and look if led over Master Volume slider
Turn on ?
I had many strange problem on my Polaris , like slider malfunction and test many IC's with scope and signal tracer, but simply replacing the ADC0804 all problems gone away !!!
Ciao 
Mario


 

--- In chromapolaris@yahoogroups.com, Eric Frampton wrote:
>
> Hi folks -
>
> So I'm finally making some progress getting this Polaris back up and on its feet. This one last issue has me stumped, tho'.
>
> On one voice only (#2 of the 6), the mod routings accessed via the Assignable Control (Osc 2 Vibrato, Osc 2 Env, Detune) aren't working right. Pulling the control positive for Osc 2 Env creates this strange band-modulated sort of thing as the oscillator sweeps down, then pulling the slider negative, instead of creating a rising pitch like the other oscillators, starts with silence and fades in. Detune doesn't do anything at all, and Vibrato creates some sort of waveform that's different from the other 5 oscillators and just plain wrong. By itself - unmodulated - the oscillator runs and tracks just fine.
>
> Again, this behavior is only on one voice - the other 5 are fine.
>
> The oscillator seems to pass the Autotune routine - at least, the Tune light blinks 6 times.
>
> Using a shotgun approach, I've tried individually swapping out the two 4051's on that voice, the LF347 for Pitch B, and the 3374 itself. No change for any of it.
>
> Any thoughts?
>
> Thanks,
> Eric
>