<br><br><div><span class="gmail_quote">On 3/14/06, <b class="gmail_sendername">Scott Croft</b> <<a href="mailto:scott.croft@cox.net">scott.croft@cox.net</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
On Mar 12, 2006, at 8:01 PM, Scott Croft wrote:<br><br>> Further to my post below I have found some additional information.<br>> It would<br>> seem to be a "grounding" type issue I think. When I plug the patch
<br>> wire<br>> into the line in of the sound card there is no hum. If I pinch the<br>> free end<br>> of the patch wire with my fingers I can cause the hum. I then<br>> attached an<br>> old headphone jack to the line in in the onboard audio card. With
<br>> the wires<br>> exposed I experimented with the audio in. If I ground the center<br>> audio wire<br>> with my fingers or something other than the CPU case I can create the<br>> hum/hiss in the right or left channel. Grounding the wire to the
<br>> CPU case<br>> dose not seem to cause the hum. Grounding the "ground" wire from<br>> the left<br>> or right wire dose not seem to cause a change in the hum. I am not<br>> much<br>> good with audio so anyone have any suggestions? Thanks in advance
<br>> for any<br>> input.<br>><br><br>Are you saying that you have hum *until* you plug the patch cord into<br>the the line in ?<br><br>Is this hum what you initially described as "hiss"?<br><br>Everything else you say is more or less normal, touching the "hot"
<br>input wire will normally cause hum, your body is acting as an antenna<br>and picking up the ambient 60-cycle buzz in the atmosphere around<br>you. Shorting the input to the case (ground) will normally eliminate<br>most if not all output.
<br><br>What you are proving is that your audio amplifier seems to be working<br>more or less normally, but if you have hum with nothing connected to<br>the input which goes away when you connect a cable to the line in I<br>
would look for a bad input connector (loose/cold solder joint etc.)<br><br>I also note that you initially said you had PCM turned up and line in<br>down ?? For the setup you describe this would be wrong, you would<br>want PCM down or muted and line in turned up, the TV card in your
<br>case is no different from the iPod as a sound source.<br><br><br><br>Yes it is more of a Buzz/hum and not a hiss, I guess I did not use the right<br>audio term!<br><br>The hum is not present at all until one of two things happen. I
<br>short/ground the left or right channel going to the line in, or I plug the<br>sound card line in to the TV card line out with the patch cable. After<br>reading and asking question I agree with you that when I touch or ground the
<br>line in I should here the buzz. The problem is that I get the same results<br>when I connect the TV card to the line in on the onboard audio (also get the<br>TV audio). Both left and right channels have the buzz.<br>
<br>I think that I tried the mixer settings you describe (think I read something<br>to the same effect) and could not get any sound at all with settings like<br>that. Not sure about this.<br><br>Since my last mail I have added a PCI sound card and disabled the onboard
<br>audio in the bios. This works with no trouble. Not the solution I wanted,<br>but it works. I am using all the same settings and hardware with the<br>exception of the onboard audio. I guess this tells me that my brand new
<br>onboard audio is broken, or I have some type of grounding problem with the<br>PC??<br><br>Again thanks for the input, it is much appreciated. I am moving on to get<br>the remote control working, and the s-video output to fill my entire TV
<br>screen.<br><br>Scott<br><br><br><br>_______________________________________________<br>mythtv-users mailing list<br><a href="mailto:mythtv-users@mythtv.org">mythtv-users@mythtv.org</a><br><a href="http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users">
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users</a><br></blockquote></div><br>I am no audio expert, but if it is truly a hum you are describing, I might think about ground-loop problems. Both of my machines with analog output have this problem. You can buy a ground loop isolator at an electronics store, or try using a 3prong --> 2prong adapter to cut out the ground loop. I have used the 2 prong adapter method on both of my computers and my subwoofer and it solved all my 'humming' problems.
<br><br>Good Luck...!<br><br>Dave Hofstra<br>