I have to rectify my previous message.
Checking better the oscilloscope 0 V calibration, I have noticed the following:
in ch II, in the voice 22, that I believed to be the faulty one, the EG VCF is ok. In all of the others, with IL at its maximum (-5), the EG diagram starts 1V higher (in the negative field) than in the previous one (that starts at about -4V).
I used to align both channels of the scope at the beginning of the EG, instead of the 0V reference, that's why the 22's peak seemed to be higher than the others� the real thing was that the other voices'EGs start about 1V above the right voltage (with IL slider at its maximum (-5), reaching the same peak...
Any help is welcome�
BTW I swapped both the VCF EG and its VCA ICs, naturally, between the faulty and good board, nothing changes.
How can 7 boards out of 8 have such a wrong behavior, considering the "cascade" connection of the control V wires?
Il giorno 12/set/2011, alle ore 23:06, Fernando Zarone ha scritto:
> Hi all,
> after about 8 months (8!) I am going to complete the overhauling / calibration of my CS80.
> The only problem I have now is that in one voice the EG Filter envelope, at both the calibration voltages/speeds (8 and 3V) , as shown by the scope, is about 1V higher than in the other voices, neither am I able to lower it in any way. I tried to workaround replacing the ICs (both the VCFEG and its VCA) and other components, but nothing.
> The result is a "more open" filter only in that voice.
> I am sure that there is somebody who faced such a problem!
> Waiting for help
> Thanks
>
> Fernando
>
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