On Sat, 11 Feb 2006 21:47:39 +0000 John Haxby <[EMAIL PROTECTED]> wrote:
> Sergei Steshenko wrote: > > >On Thu, 9 Feb 2006 12:02:10 +0000 > >John Haxby <[EMAIL PROTECTED]> wrote: > > > > > > > >>I have a Griffin iMic which works perfectly. I think it does > >>everything you want, it's also cheap: mine is the older silver model and > >>cost $35. Haven't tried (or seen) the newer white one but I'd be very > >>surprised if it didn't just work. The quality is pretty good > >>although, for some odd reason, I can hear hum from my laptop power > >>supply when I connect it to an amplifier instead of headphone. I > >>suspect that's more a problem with the laptop rather than the iMic. > >> > >> > >> > >Try a thick wire to connect your laptop's ground with your > >amplifier's one. > > > >Outer connectors shields, like the ones of serial port or display > >connector are good candidates to be used as ground. > > > > > That's a good idea. An earth loop does seem to be the most likely > problem. Mind you, neither the mixer nor the power amp have their own > earth so I suspect that it's the two computers that provide input to the > mixer having a bit of a fight. The Dell laptop power supply does seem > to have an earth connection. Alas, in the only case where it really > matters (in a theatre) adding an extra earth connection isn't > practical. It's a Dell laptop and seems to have an earth connection > running through the external power supply: other laptops I've used in > the past don't have an earth connection for the external power supply > and are probably just fine. I'm really not sure wh Dell think an earth > is important :-) The battery lasts long enough though ... > > I was somewhat surprised at the hum, but since there isn't electrical > isolation between the audio output and the rest of the computer I > shouldn't be that surprised I suppose. > > jch > > > ------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. Do you grep through log files > for problems? Stop! Download the new AJAX search engine that makes > searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 > _______________________________________________ > Alsa-user mailing list > Alsa-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/alsa-user > Regarding "ind you, neither the mixer nor the power amp have their own earth" - well, my Denon AV receiver has a special plastic capped nut on a threaded rod being marked as ground - the marks looks more or less like this: | ----- ///// . It's on the back of the receiver. If you do not have a dedicated ground connection, you probably have a lot of screws on the back of your power amp, so you can use them to connect the two grounds. ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
