[LAU] Am I experiencing ground hum or is it something else?

[Folderol]

On Sun, 29 Nov 2009 16:51:03 +0000
Andrew C <countfuzzball at gmail.com> wrote:

> Hey Fons,
> 
> How can I check if the keyboard/power supply is grounded? The power supply
> itself is a three pronged one....
> 
> Thanks.
> 
> Andrew.

If you don't have any kind of test meter, a really crude way to find out
is with a 9V battery and your tongue!

Unplug the power supply from everything. Stick one terminal of the
batter on the earth pin of the mains plug, and put your tongue
between the other terminal of the battery and the ground side of the DC
out of the power supply. You will feel a strong unpleasant (but not
dangerous) tingle if the ground connection is carried through. 

-- 
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.