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

2011-10-17 by Elby Designs

That link is there to connect the two grounds (0V and EARTH) together. In a `proper' system this should be linked as it keeps EVERYTHING at EARTH potential and electrically safe.
This link can be removed or, better still, replaced with a resistor to help control earth loops but you need to take other precautions then to ensure the integrity of your systems earthing. All metal work should really be connected to EARTH but note that many modules (especially Panthers) will provide a ground connection to the panel at the module. In an ideal system this would actually be a `panel ground' or earth or something supplied to the system through a dedicated wire on the distribution system. Unfortunately Doepfer and even MOTM decided not to offer this important feature and so it has to be addressed a different way. If you look at the Oakley system you will see that he DOES do this and it works perfect as long as you only use Oakley modules.

Best Regards
Laurie Biddulph
Mobile: 0400 257 645
Web: www.elby-designs.com

-----Original Message-----
From: cgs_synth@yahoogroups.com [mailto:cgs_synth@yahoogroups.com] On Behalf Of Stephen Richards
Sent: Tuesday, 18 October 2011 12:33 AM
To: cgs_synth@yahoogroups.com
Subject: Re: [cgs_synth] Re: Best of CGS Panel #3 Oscillator signal bleed problem

Hi Laurie

If you mean JP1 , then yes it is fitted ; wire link.

Stephen


________________________________
From: Elby Designs <elby_designs@...>
To: cgs_synth@yahoogroups.com
Sent: Monday, October 17, 2011 10:46 PM
Subject: RE: [cgs_synth] Re: Best of CGS Panel #3 Oscillator signal bleed problem



You should also note that there is a link on the All-In-One that connects the DC 0V to EARTH so you need to establish if that is fitted or not.

Best Regards
Laurie Biddulph
Mobile: 0400 257 645
Web: www.elby-designs.com

-----Original Message-----
From: cgs_synth@yahoogroups.com [mailto:cgs_synth@yahoogroups.com] On Behalf Of Stephen Richards
Sent: Monday, 17 October 2011 10:32 PM
To: cgs_synth@yahoogroups.com
Subject: Re: [cgs_synth] Re: Best of CGS Panel #3 Oscillator signal bleed problem

Thanks again Ken and Mike ; I'm going to have to digest this all.

This is what i now have : I have just removed the Banana Jack Signal Ground from the Earth Stud and connected it to one of two 0V on the 15V side of the Power Module. (this is the only change i have ever made to the power setup).

To Banana Jack Signal Ground i connect the sleeve of my Synth Panel Output Cable. Tip is Signal. The Banana Jack is mounted to the side wall of the same Hammond Metal Box that contains the Power Module but it is a plastic jack so insulated from the Box.

Removing the Banana Jack Signal Ground from the Earth Stud has made zero difference to my original problem.

In fact , as before/always ; the Signal Ground does not make any difference connected or otherwise ! I completely stumped here.

When you say you never connect the Signal Ground to Mains Ground directly ,
should i run my Signal Ground on the 15V side back to the Earth Stud via a 1K 1 Watt resistor ?

In regards to the Hammond box metal , do i need to ground that to the Earth Stud ?

Stephen

________________________________
From: "sasami@..." <sasami@...>
To: cgs_synth@yahoogroups.com
Sent: Monday, October 17, 2011 8:24 PM
Subject: Re: [cgs_synth] Re: Best of CGS Panel #3 Oscillator signal bleed problem

I never connect my signal ground directly to mains ground. I always put a 1k
1 watt resistor between the two. This helps prevent ground/hum loops. That
also means that my panels cannot be mounted hard to a metal case that is
grounded to mains earth. I solve that by having my power supplies in their
own metal cases which are earthed to mains earth. The resistor between 0V
and mains earth is then installed in the power supply. If the power supply
needs to go into the same case as the rest of the synth, the power supply's
own smaller cabinet is mounted using some sort of insulators, such as small
rubber shock mounts, and the 0V connection is connected to the panel/case
earth.

Ken

>Hi Mike
>
>I'm connected to the Main Earth Stud on the 240V side for the Signal
Out Ground Connection.
>
>So i should connect Signal Out Ground Connection to the Ground on the 15V
side , is that correct ?
>
>Do any of the Earth / Ground connections need to be physically connected to
the Chassis ?
>
>I'm going to keep my Signal Out Ground connection at the Power Module is it
is at the beginning point for multiple module connections.
>
>My module power connections are Daisy chained pre CGS distro boards.
>
>cheers for the help
>
>Stephen
>
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>
>
>
>------------------------------------
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>Yahoo! Groups Links
>
>
>
>
__________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

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------------------------------------

The CGS Modular Synth home page: http://www.cgs.synth.net/
Yahoo! Groups Links




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------------------------------------

The CGS Modular Synth home page: http://www.cgs.synth.net/
Yahoo! Groups Links

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