Which ground to case?

[robzy]

Hey there guys,

I was wondering whether i should hook-up the enclosure for my dynalo to 240v AC earth, PSU DC ground, or signal ground?

Thanks,
Rob.

 

[skyskraper]

all of the above! psu ground on the dynalo is tied to signal ground (as opposed to single voltage designs with a virtual ground) so run a wire from signal or psu ground connectors to the case and the AC ground to the case

 

[robzy]

Quote:

Originally Posted by skyskraper all of the above! psu ground on the dynalo is tied to signal ground (as opposed to single voltage designs with a virtual ground) so run a wire from signal or psu ground connectors to the case and the AC ground to the case

Well.... that makes that easy

Rob.

 

[amb]

Be very careful if you tie signal ground to AC ground in your amp. If any other component in your signal chain also has signal ground tied to AC ground, then you will have a ground loop, which will result in hum and noise. If you must tie AC ground to the case, then I suggest installing a ground loop breaker between the case and the signal ground.

A simple ground loop breaker is a 10Ω 5W resistor in parallel with a 0.1µF 400V+ film capacitor with a class X or Y rating.

 

[robzy]

Bugger it then, no tying to AC Ground.

Just good 'ole DC ground.

Rob.

 

[Voodoochile]

Check out the Rod Elliot article on earthing. Here is a diagram of his solution:

Found here.
This is just an expansion of what AMB is referring to. I've used it, it's simple and works well (and is safe).