Re: piezo pick hum

[andy butler <akbutler@tiscali.co.uk>]

Hi Michael,
last thing it's going to be it "the piezo".
..and unlikely the the circuitry connecting the piezo
to the o/p of the guitar is creating a whine.

The sound is more typical of those that are produced by 
a laptop/soundcard combination that isn't  well earthed for audio.
With the ultimate culprit being the laptop power supply.

Rusty's solution sounds good. 
& +1 for Dennis


Other things to try
1) change the whole jack cable 
2) run laptop on batteries (most common fix for that noise)
3) change technician ;-)   

Other wise not possible to troubleshoot at a distance without knowing the 
setup.

Need to know how the audio interface is powered.



andy


Michael Peters wrote:
> http://www.michaelpeters.de/temp/soloette-hum_0001_0.wav
>
> When I plug my Graduette Soloette guitar (a nylon string travel guitar with
> a piezo pick) into the external soundcard of the laptop and launch Bidule 
> to
> hear it, I find that it hums - a deep drone hum plus a high whining sound.
> This does not happen with regular electric guitars. My technician says it
> has to do with the piezo. When I put a finger on the jack cable that sits 
> in
> the connector in the guitar, the noise stops.  
>
> I can get rid of the deep hum with a plugin, but the high whining noise is
> still there. I can't play with my finger on the jack cable all the time. Is
> there a simple way to get rid of that noise?  a special VST plugin?  or 
> some
> kind of grounding cable that I connect to the plug? and where does the 
> other
> end go?  I need a quick and simple solution. Help!
>
> -Michael