To Float or not to Float...


I have a DeHavilland preamp which has a switch allowing one to "float" the ground.  I've always used it in the "float" position, however recently, perhaps due to some connectivity issues with my interconnects, there is a small buzz emanating from my speakers with the switch in this position.  The buzz disappears when I flip the preamp switch to the "ground" position.  Irrespective of the buzzing, is there any sonic advantage (or disadvantage) to "floating" the preamp ground in this situation??
Thanks for your informed opinions...

weebeesdad

Showing 1 response by thom_at_galibier_design

Cleeds wrote:

This is extremely dangerous - interconnects are not intended to carry safety grounds. Following this practice means that a component's chassis could be energized with lethal voltage. Safety grounds should be "earthed" only through a properly grounded power cord, or a chassis that is itself directly connected to a safety ground.
This is absolutely correct, and it amazes me that audiophiles will accept a potentially lethal component in their house.  Interconnects are not designed to carry a safety ground.

There are several techniques for eliminating ground loops while at the same time having every component's SIGNAL ground connected to the SAFETY ground (i.e. the chassis and ground lug of the mains outlet) .

Look at section 15.10 of the document downloadable on this page for one sample solution:  http://www.valvewizard.co.uk/Grounding.html

It would be easy to retrofit the above suggested circuit (4 parts) into a vacuum tube component (especially one that's hard-wired).

Cheers,
Thom @ Galibier Design