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Old November 29th 17, 12:31 PM posted to uk.rec.audio
Woody[_4_]
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Posts: 145
Default Running an amplifier unearthed


"Dave Plowman (News)" wrote in message
...
In article ,
Woody wrote:
In practice if there is to be an earth within a hi-fi system there
should only ever be one and very often that used to be on the
turntable. If there is more than one you will likely end up with a
'hum loop' around the multiple earths causing a very low level but
continuous hum form the speakers.


I've never ever seen a system where the mains earth is provided via
the
turntable. Most usually by the device where the mains is switched
from
like the amp or pre-amp, if that supplies switched mains for other
things.

Signal ground is a different matter.



Although it is getting on a bit my Hitachi DD turntable has three-core
mains and the chassis and pickup are connected to it - don't ask me
why as I don't know. However I have never had any audible hum on the
system, and my amp and all the other separates are two-core mains.


--
Woody

harrogate3 at ntlworld dot com