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Cgs synth

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Re: CGS28 Bleed and channel mutes

2015-06-25 by Ken Stone

Start with checking the voltages to the power rails of the chip. Make sure the -0.6 is working (-0.7 V is acceptable).

Ken

On Fri, Jun 26, 2015 at 2:39 AM, spunraddish@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

This should be my last question here for a bit, seeing as I've got the other 15 or so PCBs working on their own; I've built up my sequential switch, and it has some funny behavior. The clocking is perfect and the state address is mostly correct, but hte default state is backwards, though that may just be a wiring mishap. The direction change and inhibit input work perfectly.


Here are the issues;
Channel 1 bleeds into channel 2.
Channel 2's input is muted.
Channel 3 bleeds into channel 4.
Channel 4 is muted.
Channel 5 is fine.
Channel 6 bleeds into all channels a bit, but opens with the occasional distortion.
Channel 7 bleeds a lot into all channels.
Channel 8 bleeds a bit into channel 7.
The reset input doesn't work.

I've already swapped out the 072 and the 4051 that does the multiplexing, to no effect. The 4051 is the same manufacturer as the original chip, which I believe to be TI. Some channels fire better when in reverse direction.

I am also running this on +/-12V; any ideas?

Thanks,
Eric





--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

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