# Optical audio works with one, but NOT two Toslink keystone couplers?



## nutlog (Dec 16, 2008)

So to avoid a long description, I whipped up an awesome diagram of the problem I'm having.

Long story short, I'm running HDMI, USB, and digital audio (optical cable) from my PC downstairs to my TV upstairs, but I can't get the audio to work when using these keystone couplers in wall plates:

http://www.monoprice.com/products/p...=10426&cs_id=1042610&p_id=8729&seq=1&format=2

I've tried swapping cables, using both keystone couplers in each position, etc -- so I know both couplers and all 3 of my optical cables work fine. I can run audio from my PC to receiver using ANY 2 cables and EITHER coupler. But once I introduce a second coupler and 3rd cable, I get no audio. Note that I DO still get the red light coming through all 3 cables, so it appears there's still a signal -- it's just not producing audio.

Any help would be great. Thanks!


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## hyunelan2 (Aug 14, 2007)

Perhaps you are exceeding the usable length for TOSLINK? I'm not sure what their maximum is.

Quick question - if you are running HDMI, why bother with the separate cable for audio?


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## nutlog (Dec 16, 2008)

hyunelan2 said:


> Perhaps you are exceeding the usable length for TOSLINK? I'm not sure what their maximum is.
> 
> Quick question - if you are running HDMI, why bother with the separate cable for audio?


Yeah, that does appear to be the case. I don't know what the max allowable length is either, but I do have a 6-footer going to the wall (A), a 15-ft behind the wall (B), and an 8 or 9-ft connecting upstairs (C). And it's when I connect "C" that I lose the audio... like the signal is fine traveling the first 21 feet, but won't make it 30 feet. Definitely makes sense. I'm sure there's some signal loss in those $1.48 couplers as well. So I'm going to try a $20 Toslink signal amplifier and/or some shorter (1.5ft or 3ft) cables and see if that does the trick. Thanks for the reply!

As for using a separate audio cable, I brought my PC upstairs to test everything before I bothered running cables through my wall. And for whatever reason, my particular setup did not like to put the HDMI audio in surround. Not sure if it was because it was going HDMI in to the TV, then optical out from the TV to the receiver (my receiver is a Yamaha from 2002 -- still sounds great, but no HDMI). Or maybe I totally biffed some setting on my PC...? But either way, the rear speaker sounds merged into the front speakers and basically made it stereo instead of surround. Switched over to optical out from my PC to the receiver, and surround works perfectly. :huh:


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## hyunelan2 (Aug 14, 2007)

Yes, looping the audio through the TV is the issue. I have the same problem with no HDMI on my circa 2004 Onkyo. 

Computer 7.1 signal -> TV 2.0 Signal -> Receiver = receiver only gets the 2.0 signal. 

I need to go straight from the computer to the receiver to get the full DTS signal. I can use Pro Logic to get 5 channels back, but it's not Dolby Digital/DTS. In my theater setup I'm building, I plan to get around all those issues by just using and HDMI compliant receiver.


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## nutlog (Dec 16, 2008)

Yeah, good call. Glad to know I'm not crazy.

For now I think this $19 signal amplifier is going to have to come before a new $400 receiver.  But I also look forward to having a setup that doesn't require a convoluted system of HDMI/Toslink splitters and fancy Harmony Remote activities to set all my components to their various settings to give me surround sound.


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## gregzoll (Dec 25, 2006)

Most if not all tv sets do not accept audio in through the Toslink, they output. If wanting audio also upstairs on the tv, along with video, go with HDMI over ethernet.


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## nutlog (Dec 16, 2008)

gregzoll said:


> Most if not all tv sets do not accept audio in through the Toslink, they output. If wanting audio also upstairs on the tv, along with video, go with HDMI over ethernet.


You're correct -- my Panasonic plasma accepts HDMI in and Toslink out, but that audio comes out in stereo instead of surround. I actually need surround audio from my receiver, not so much the TV itself; so if I go Toslink out from my PC straight to my receiver, I get the full surround. 

I had looked into HDMI over ethernet before I started this, but I already have the Toslink running through the wall and an optical signal amplifier and a few shorter cables on their way from Amazon... so we'll see how that goes.


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## beto980 (5 mo ago)

did you get to fix this problem? I am having the same issue and is driving me crazy, please let me know, thanks.


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