-----Original Message----- From: Danny [mailto:mynixm...@gmail.com] Sent: Friday, October 02, 2015 8:27 AM To: debian-user@lists.debian.org Subject: Re: Sound card question
> I believe that the output of the headphone jack is not impedance > matched--I expect it's just a voltage source. Wat's more, unless you > are plugging the same low-impedance devices into both Y outputs, _and_ > the source is impedance matched, you would not split the power > equally. I don't know what you want to do with the second output, but it's more than likely a relatively high impedance, so it would not load the circuit at all. > I could be wrong, but it seems logical to me. > > --doug O.k ... let me explain why I asked the question for the sake of satisfying any curiosity: I have EchoLink (Ham Radio VOIP) connected to Jessie like this: VHF Transceiver (with two interface cables going to the MIC and LINE-OUT jacks on the back of an internal sound card. Incoming audio (radio frequency) goes through the antenna ... through the transciever ... to the sound card (via the MIC interface cable) ... it gets processed by the sound card and stuff happens on VOIP ... Because the VHF transceiver is effectively turned into a repeater NO transmit or recieve audio can be heard on the transciever itself (as it should be). In order to hear comms coming in or out of the transciever (via an antenna) one has to connect to the transciever with ANOTHER transciever in order to hear people talk (if you are tuned to the same frequency off course) Now ... my second transciever is fitted inside my car ... in order for me to hear all comms on the frequency I need to go to my car and turn that transciever on every now and then which becomes a pain in the donkey ... ;) ... In order for me NOT to make a trip to the car every 10 minutes I though of splitting the LINE-OUT and add a normal set of desktop speakers. So ... I was just wondering if I will have any losses (in whatever form) when I "split" the signal ... keep in mind that the audio signals processed by the sound card should be strong and reliable ... Thank You Danny Normally when a signal is "split" you should have "identical" impedences on both sides of the split. Assuming this is so the resulting signal on either side of the split should be down by 3db or "half". Normally the amplifiers which are at the end of the split signal have enough gain so that 3db should not affect the sound quality. Larry
