Re: Am I experiencing ground hum or is it something else?

[Andrew C <countfuzzball@xxxxxxxxx>]

Just out of interest Will, I've already tried 2 separate power supply plugs into my keyboard, and I still get an annoying noise when plugging them into an amp/line in on my PC soundcard. The keyboard has onboard speakers, but I can't detect any annoying noise when the keyboard volume is up full, with my ear against the speaker...

This might be a problem with my sockets and/or my keyboard line outs being futzed?

Thanks,

Andrew.

On Mon, Nov 30, 2009 at 7:15 AM, Will Light <visinin@xxxxxxxxx> wrote:

but I've had issues with
noises like the one you posted that stemmed from, of all things, the
power supply being grounded.

-w

On Sun, Nov 29, 2009 at 2:10 PM, Andrew C <countfuzzball@xxxxxxxxx> wrote:
> 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@xxxxxxxxx>
> wrote:
>>
>> On Sun, 2009-11-29 at 18:44 +0100, fons@xxxxxxxxxxxxxxx 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,
>> >
>>
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