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

Clemens Ladisch clemens at ladisch.de
Thu Jul 29 03:35:54 EDT 2004


Phil Carter 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.

Apparently, some MIDI IN connector has pin 2 connected to the ground,
which is a Bad Thing(TM) to do; see
<http://www.midi.org/about-midi/electrical.shtml>.

> Is there anything I can do to correct this? Is it because I have a
> cheap sound card? I've thought about getting a somewhat better
> soundcard, possibly an SB Live!, or a USB midi interface instead
> of my gameport midi interface.

The ground loop might be caused by your gameport MIDI interface, so
there is the possibility that you have a chance that a USB MIDI
interface might fix the problem, if you're lucky.  However, many other
devices get this wrong, too.

You could try to 'modify' your interface so that pin 2 (the middle
pin) of the MIDI IN connector is permanently disconnected ...


Regards,
Clemens





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