Definitive earthing advice sought.

[Nuuk]

The problem seems to be:- how to assemble the PSU and connect the PSU to the outside world.

Do you mean what goes on the primary side of the transformer? I find a mains lead, fuse and switch is sufficient for say up to 500 VA, ie no soft-start required. Or are there other options?

[AndrewT]

No, I mean the secondary side.

[kvholio]

How's this one ?



Regards,

Klaas

[AndrewT]

Hi Kv,
do you want/need my approval?

[kvholio]

No Andrew, this is as far as my reasoning concerning grounding goes. I hope it explains it clearly.

Best regards,

Klaas

[Nuuk]

Kv, the bit that says 'keep this physically compact as possible" may deter people from putting the PSU in a separate housing.

In my experience, placing the transformer and bridge in a box, with up to a meter of cable connecting it to the amp circuit still results in a perfectly quiet GC.

For me the $64,000 question is, when housing the PSU separately, is it best to have the rectifier bridge with the transformer or in the amp case?

[kvholio]

For me the $64,000 question is, when housing the PSU separately, is it best to have the rectifier bridge with the transformer or in the amp case?

Thats a tough one, Nuuk..
Let me try (this is my reasoning)
The bridge-rectifier is noisy part, so you want to keep it as far away from the amplifier-circuitry as possible.
By moving the bridge-rectifier to the separate psu-case, the R-component between rectifier and psu-capacity will increase, effectively creating an RC-filter.
This will make the psu less noisy.

Best regards,

Klaas

[Nuuk]

The bridge-rectifier is noisy part, so you want to keep it as far away from the amplifier-circuitry as possible.
By moving the bridge-rectifier to the separate psu-case, the R-component between rectifier and psu-capacity will increase, effectively creating an RC-filter.
This will make the psu less noisy.

That's the reasoning that I have used so far. Plus, to me at least, it seems preferable to have DC in those umbilicals than AC!

[kvholio]

it seems preferable to have DC in those umbilicals than AC!

Perhaps you can elaborate on that ?
I don't see any problem with AC in those umbilicals.
The only problem i see is this AC entering the separate amplifier-case.

Best regards,

Klaas

[Nuuk]

Perhaps you can elaborate on that ?

It's based on nothing more than a hunch! I thought AC may affect anything around it more than DC so with the interconnects etc passing close to the PSU umbilicals, I prefer to to stay with DC.