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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...

128x128weebeesdad
erik_squires
16,123 posts
 
The buzz is your answer.

Best,

E
auxinput
2,920 posts
 
I believe the "float" switch is there for some equipment which have circuits that depend on a "floating ground".  It is always best to disable "float" and set it to "ground" position unless there is a reason not to.
georgehifi's avatar
georgehifi
10,312 posts
 
I've never had any hum or buzz problems, but I follow this:
 
Ideally the system should only have one ground point via the mains plug, be it amp, preamp or source. This way there is no "earth loop" via the grounds and your house earthing. As all earths are carried to the all three components via the interconnects to the ones that aren't.
Myself I like the one earth to be at the poweramps end because it's the least sensitive component and any rf gets dumped to it. Others like it to be the preamp because it's in the middle and represents "star earthing".

Cheers George  
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