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Cgs synth

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Re: Best of CGS Panel #3 Oscillator signal bleed problem

2011-10-17 by magman2112

Hi Stephen,

Can I double check with you about the signal ground connections?

On the PSU are you connecting to the chassis mains earth or the 0V (ground) connection, as you should definitely be using the 0V connection? The signals in the CGS48 oscillator are with reference to 0V and the Elby PSU may not connect the mains earth directly to the 0V.

On my Best of CGS panels, I used one of Ken's CGS66 PSU's. This actually has provision for a "Star Earth" point which is at 0V on the PSU side (not the mains), I connected a banana jack to this point on the outside of my case and use this to connect to other equipment so the ground levels are commoned. The mains earth is connected to the metal front panel only.

Hope this helps

Regards

Mike

--- In cgs_synth@yahoogroups.com, "Stephen" <okayjustalittle@...> wrote:
>
> Hi Ken and All
>
> I built the Best of CGS Panel #3 last year and i have never been able to get rid of the signal bleed from the CGS 48 oscillators.
>
> To describe what is happening : Even with nothing patched ; when i plug the panel's output into a mixer , even with the output turned all the way down , i can still hear the oscillators in the background regardless of whether i take my output signal from VCA's or from the Dual Mixer.
>
> I am powering the panel with and elby all in one power module 30VA +/-15VDC.
>
> I'm using a split output cable with the Earth coming off the Sleeve , Output signal is on the Tip. That Earth from the cable goes to a Banana Jack connected to the Power Module's main Earth Stud.
>
> On the 15V side of the Power Module + , - and Earth is connected to the panel via CGS Distro which is insulated from the Chassis.
>
> I have not taken any Earth Connection directly to the Chassis.
>
> many thanks
>
> Stephen
>

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