29 Nov
2009
29 Nov
'09
12:51 p.m.
Hey Fons,
How can I check if the keyboard/power supply is grounded? The power supply
itself is a three pronged one....
Thanks.
Andrew.
On Sun, Nov 29, 2009 at 3:55 PM, <fons(a)kokkinizita.net> wrote:
On Sun, Nov 29, 2009 at 03:16:33PM +0000, Andrew C
wrote:
I'm just wondering, is the start of this
short recording a ground hum
loop? It appears to be a weird high pitched whine in there as well...
325.3 Hz and harmonics, either from digital circuits in your
keyboard, or from a switching power supply.
Is the keyboard itself grounded ? If not try that first (if
it has a ground pin...)
Could a DI box solve this problem?
One that provides ground separation (i.e. with
a transformer) probably will.
Ciao,
--
FA
Io lo dico sempre: l'Italia è troppo stretta e lunga.
29 Nov
29 Nov
1:17 p.m.
New subject: Am I experiencing ground hum or is it something else?
On Sun, 29 Nov 2009 16:51:03 +0000
Andrew C <countfuzzball(a)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.
1:52 p.m.
New subject: Am I experiencing ground hum or is it something else?
On Sun, Nov 29, 2009 at 04:51:03PM +0000, Andrew C wrote:
How can I check if the keyboard/power supply is
grounded? The power supply
itself is a three pronged one....
Then in most countries it is required by law to be
effectively grounded. Next question is if you power
socket is... It should be if it accepts the plug.
Since you also have this interference with an amp,
but not with the headphones it really seems to be
a grounding problem.
To only other way to explain it would be to assume
it's some high-frequency stuff which your headphones
would just ignore, but any active input such the amp
or soundcard could demodulate into the audio band.
If you're using a laptop, does running it on battery
make a difference ?
Anyway I'd try a DI box, it's good practice anyway with
all instruments.
Ciao,
--
FA
Io lo dico sempre: l'Italia è troppo stretta e lunga.
2:31 p.m.
New subject: Am I experiencing ground hum or is it something else?
On Sun, 2009-11-29 at 18:44 +0100, fons(a)kokkinizita.net wrote:
Are you plugging the devices into different outlets?
Rich...
How can I
check if the keyboard/power supply is grounded? The power supply
itself is a three pronged one....
Then in most countries it is required by law to be
effectively grounded. Next question is if you power
socket is... It should be if it accepts the plug.
Since you also have this interference with an amp,
but not with the headphones it really seems to be
a grounding problem.
To only other way to explain it would be to assume
it's some high-frequency stuff which your headphones
would just ignore, but any active input such the amp
or soundcard could demodulate into the audio band.
If you're using a laptop, does running it on battery
make a difference ?
Anyway I'd try a DI box, it's good practice anyway with
all instruments.
Ciao,
3:10 p.m.
New subject: Am I experiencing ground hum or is it something else?
Hey Rich,
Yeah, I plugged both keyboard and amp into different outlets, and I got the
same noise. :/
Will, I'll test that out tommorrow, when I get a 9 volt battery or two.
Also, just for the hell of it, I'll get a DI box anyway, just to see if it
does anything for it.
Andrew.
On Sun, Nov 29, 2009 at 6:31 PM, Ricardus Vincente
<wizardofgosz(a)gmail.com>wrote;wrote:
On Sun, 2009-11-29 at 18:44 +0100,
fons(a)kokkinizita.net wrote:
Are you plugging the devices into different outlets?
Rich...
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Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
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> How can I check if the keyboard/power supply
is grounded? The power
supply
itself is
a three pronged one....
Then in most countries it is required by law to be
effectively grounded. Next question is if you power
socket is... It should be if it accepts the plug.
Since you also have this interference with an amp,
but not with the headphones it really seems to be
a grounding problem.
To only other way to explain it would be to assume
it's some high-frequency stuff which your headphones
would just ignore, but any active input such the amp
or soundcard could demodulate into the audio band.
If you're using a laptop, does running it on battery
make a difference ?
Anyway I'd try a DI box, it's good practice anyway with
all instruments.
Ciao,
5285
days inactive
5285
days old
linux-audio-user@lists.linuxaudio.org
4 comments
4 participants
participants (4)
-
Andrew C -
Folderol -
fons＠kokkinizita.net -
Ricardus Vincente