[linux-audio-user] Re: Getting audio noise through midi cable

[John Check]

On Saturday 31 July 2004 08:44 pm, Andrew Burgess wrote:
> >I have my keyboard midi ports connected to my computer through the
> >game port on my motherboard sound card. It works fine, except I'm
> >hearing some noise through the audio output on my keyboard when the
> >midi cable is plugged into my computer. Whenever my computer is on
> >(whether or not the keyboard is), I hear a buzz, and it gets louder
> >whenever the hard disk is in use. Is there anything I can do to
> >correct this?
>
> I had some really strange pops and buzzes with a new soundcard yesterday,
> Turns out I'd forgotten to go in with alsamixer and mute/turn down
> all the inputs I wasn't using. The unmuted mic input was the problem
> even though nothing was plugged into it.
>
> Worth a try...

First rule of trying to master anything on a PC, mute every channel that's not 
being used. It's pretty noisy RF-wise inside the case and nothing is properly 
shielded. Even if you use the digital side of the CD player connection, the 
wire is still an antenna. FM synth chips are also noisy at idle.