I’ve been reading articles by Graham Hinton, they are very helpful, but a bit complex to understand sometimes, for a non technical person like me.
I’ve been having intermittent hum, noise issues, with my modular system, comprising three cases, all with separate PSU's.
I’m finding sometimes that when I connect a module in one case, to a module in another, I get a weak signal, hum, and noise, that is, until I touch both cases with my fingers, then it goes away.
One of my cases has a three pin IEC mains connector, the other two cases are external PSU's, connected via two core low voltage cables, with no earth wires.
I "seem" to have cured the problems, by connecting two of the cases together via a short length of wire connected under the screws of adjacent modules in either cabinet, like an earth strap, between the two boxes.
I’m not getting any issues so far, but I’m wondering if I’ve done the right thing.
Graham Hinton seems to use a complex system of buss bars, with cabinets connected to those, but trying to figure out how that all works is a mystery to me.
Modular case earthing issues.
Re: Modular case earthing issues.
Arpangel wrote: ↑Sun Feb 12, 2023 9:54 amI "seem" to have cured the problems, by connecting two of the cases together via a short length of wire connected under the screws of adjacent modules in either cabinet, like an earth strap, between the two boxes.
I’m not getting any issues so far, but I’m wondering if I’ve done the right thing.
Yes. There might be neater ways to do it, but fundamentally you've arranged the cases to have a common reference ground, so job done.
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- Hugh Robjohns
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In my world, things get less strange when I read the manual...
(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
Re: Modular case earthing issues.
Hugh Robjohns wrote: ↑Sun Feb 12, 2023 11:17 amArpangel wrote: ↑Sun Feb 12, 2023 9:54 amI "seem" to have cured the problems, by connecting two of the cases together via a short length of wire connected under the screws of adjacent modules in either cabinet, like an earth strap, between the two boxes.
I’m not getting any issues so far, but I’m wondering if I’ve done the right thing.
Yes. There might be neater ways to do it, but fundamentally you've arranged the cases to have a common reference ground, so job done.
Thanks Hugh, yes, hope it doesn’t come back.
Advanced hybrid constructivist.
Re: Modular case earthing issues.
He's touching double-insulated things in a damp cellar....
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- Hugh Robjohns
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In my world, things get less strange when I read the manual...
(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
Re: Modular case earthing issues.
No, the hmmmm has gone away thanks to the earth bonding... 
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- Hugh Robjohns
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Posts: 43047 Joined: Fri Jul 25, 2003 12:00 am
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(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
Re: Modular case earthing issues.
Reminds me of the time I was sent to a factory to fix a machine that was knocking out the isolators within seconds of them being reset. I took one look at the cascade of water coming through the roof (it was chucking it down outside) and refused to go anywhere near it. When I got back to the office I was called in by the boss who had a big grin on his face who informed me that he'd had a complaint, and had told the factory boss none of our guys would be going there until they fixed the roof.
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Re: Modular case earthing issues.
These are all Doepfer PSU's, but, some don’t have IEC leads with an obvious earth connection, some have external wall warts, that don’t have a dedicated earth.
Advanced hybrid constructivist.
Re: Modular case earthing issues.
I had a similar issue with multiple Rackbrute cases. I felt quite demoralised after speaking to Graham Hinton as the fix seemed to a hard pill to swallow. I sold the Rackbrutes and bought a Doepfer monster case which is great but I am reaching the point where I will need a second. Glad there is a cheap fix- the joys of unbalanced connections 
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64GB.
Re: Modular case earthing issues.
Chimera wrote: ↑Sat Feb 18, 2023 4:03 pm I had a similar issue with multiple Rackbrute cases. I felt quite demoralised after speaking to Graham Hinton as the fix seemed to a hard pill to swallow. I sold the Rackbrutes and bought a Doepfer monster case which is great but I am reaching the point where I will need a second. Glad there is a cheap fix- the joys of unbalanced connections
All I did was put a bit of wire under a module screw on one case, and connect the other end to a screw on the other, it seems to have worked fine.
Advanced hybrid constructivist.