Digital Audio Input Question (1 Viewer)

[MatthewEH]

I have the Onkyo SR600 Receiver and it has 2 optical and one coaxial audio ports in the read. My question is, are there any adapters that would allow splitting of the digital coaxial input to allow multiple sources to input digital coaxial on that one receiver input.

Would I be able to use the regular RCA splitters to accomplish this or would I need a specialized adapter?

Thanks

 

[AaronBatiuk]

Matthew,
Digital audio on coax cable (S/PDIF format) has very much the same specifications as standard video: 0.7 V, 75 Ohm, and about 6 Mhz bandwidth (S/PDIF is rated up to 8 MHz actually). This is why you can use normal (good quality)video cables instead of special expensive "digital audio" cables. You will also have no problem using a normal video input selector, like the kind that radio shack sells. Don't try to use a splitter - use a selector, like the kind you can find here. Try to get one without S-video or that does not convert composite video to S-video. That may munge the digital audio signal. Some can operate with a remote control (you teach it to respond to any button you want on any remote you already have).

 

[MatthewEH]

Well, I've seen the selectors, but what I would like to do is be able to just select the video source on my receiver and not have to worry about manually switching the audio source on the selector. Thats why I was inquiring in regards to a splitter.

Is there a specific problem in using a splitter such as you'd find for regular RCA type inputs? I have seen the TOSLINK splitters like on partsexpress.com and another option would be to get a coaxial -> optical converter and then utilize the optical splitter. That, however would not be as optimal as a coaxial splitter.

Thanks for the input.

 

[AaronBatiuk]

The problem with trying to use a splitter is that you are not trying to split one signal into two, but rather, you are trying to combine two signals into one. Each input signal will interfere with the other. This might work, but you will have to make sure to turn off the other components that are not in use, so that their output does not interfere with the one you are trying to listen to.

Here's a possible workaround:
This assumes that you can assign the digital input to all of the input sources that you want (select DVD, and the coax digital input is used, select TV, the coax digital input is used, etc.). I know that some Sony receivers can do this; don't know about Onyko. Ok, take the digital output from each source and connect them to the video inputs of the receiver. Make sure to also connect the S-video cable for the actual video signal. Now, your receiver should output the S-video signal from the selected source through it's S-video output, and the digital audio through it's video output. (DO NOT try to use the analog audio inputs/outputs for this. A digital audio signal is - by design - quite similar to a video signal, but way different from an analog audio signal.) Now connect the receiver's video output (the one that normally goes to the monitor/TV) to it's coax digital audio input. Whatever source you select will have it's digtial audio sent to the digital audio input of the receiver. Again, the catch-22 is that the digital audio input is usually assigned to a single input source... You'll have to be able to assign it to all of those sources or be able to manually select it (video from one source and audio from another).
Make sure also that you do not try to use the receiver's on-screen display (if it has one) as this will probably munge the signal as well.

 

[MatthewEH]

Well the items that would be merged in the splitter would be only in use at individual times, so there shouldn't be any crossover interference. Basically one coaxial input would be from a DVD player and one input would be from a computer sound card. The onkyo allows selection of the audio source from the two optical and one coaxial digital sources, so that part should not be a problem. The workaround you mentioned wouldn't work for me as I need both SVideo and Composite (as well as Component) inputs into the television. It is an interesting idea, however.

Thanks