Chassis, ground, earth: connect?

[starbase218]

Some time ago, a forum member (not from this forum) made a suggestion for improving my amp (death of zen). He said that a mains cable with earth lead could improve things, for example by neutralizing EMI. Since my amp is lying on the floor right now (some other things I need to do about it), I have a chance to include this upgrade.

But then I started thinking: the amplifier's ground is connected to the chassis as well. If I connect the earth lead, and use an earthed wall socket, the ground will be connected to earth. My cd-player (Cambridge 640C) also has a mains cable with earth. If two interconnected devices are connected to earth in this way, won't they create a ground loop? Can I expect problems?

[00940]

It would first of all greatly improve your safety. Good safety practice would require to have mains earth always connected to the chassis and the signal ground either :
- isolated from your chassis (if the voltages are not too high);
- connected by a wire from your ground star point to the earth point (best);
- connected to the earth point through a ground loop breaker.

Honnestly, you should do a search with "ground loop" or "ground loop breaker". This topic has been covered quite a lot already.

[starbase218]

Originally posted by 00940
It would first of all greatly improve your safety. Good safety practice would require to have mains earth always connected to the chassis and the signal ground either :
- isolated from your chassis (if the voltages are not too high);
- connected by a wire from your ground star point to the earth point (best);
- connected to the earth point through a ground loop breaker.

Honnestly, you should do a search with "ground loop" or "ground loop breaker". This topic has been covered quite a lot already.

Sorry for not searching thoroughly.. I just found an article on Rods site covering this topic .

I have checked my cd-player. Its mains earth is connected to the chassis, but apparently, not to the signal ground. I'm now thinking of applying the same strategy to my amplifier. It would require re-mounting all the cinch connectors on a non-conducting panel, and then mount that panel on the amp's backside, but it looks like the best solution to me. In addition, I could finally use one of those fancy IEC sockets that are common on computers. Quite a bit more work than I had in mind, but it might be worth it. And in the meantime, I do have a spare amp .

The power supplies' secondary voltage is 25 volts, and about 32 volts under load after rectification. I think this would be acceptable.
Any comments are welcome though.

[Gordy]

Regarding earth / ground, please refer to the links that I posted in this thread: Optimal grounding?