I have a spdif input (44.1KHz) from a computer (mythtv) to my 990 and I get no sound. Same cable from the computer to a Technics decoder box works fine. Same 990 input from same computer when computer is playing TV (48KHz) plays fine. Same input to 990 from a CD player works fine.

When the 990 has this non-playing input, I have digital lock but cannot cycle through STEREO, Dolby, etc. like I can when the CD is the source.

My setup is has 2 spdif outputs from the computer going to the Technics decoder which feeds the Tv and the 990 which feeds a 5.1 system.

What should I do?

Allen

What does the Technics decoder do, exactly? Is it simply a DAC, or is it decoding some special format (DD, for example)? That might help troubleshoot the problem.

The Technics SH-AC500D Digital Surround Processor can decode DD, PCM, DTS, or Stereo. It can take either coax or optical S/PDIF inputs. I am using a coax input and it is set to Stereo at the moment. It will also play fine with this input on Surround but not on DTS, which seems correct.

So again, a 44.1HKz digital coax s/pdif signal that plays fine fed to this Technics decoder will not play when fed to the 990.

Allen

I solved this by changing my configuration on the mythTV box. I removed my /etc/asound.conf file and changed the default sound device to ALSA:spdif. If anyone cares, I am using Mythbuntu 8.04

Previously, ALSA was creating the output configured per a mythtv wiki.

All is well although I have no idea why the 990 would not play a stream that the Technics would play. At this point, I guess it isn't really important.

I used to own the exact same Technics decoder until about 4 years ago. I also have MythTv playing through the 990 via the USB connection.

What kind of signal is your sound card sending to the 990? Do you actually get DD/DTS out to the 990?

I don't have a sophisticated sound card, so I use USB for sound. I recommend you give that a try as well - at least you'll have a backup plan.

Hi and thanks for the reply. I have tried USB and it works as well. Right now I have spdif outputs from my MB's built in HDA sound card.

I wanted two audio outputs, one 2.0 and one 5.1 and all I could figure out was doing this with the two converters. I would like to do the 2.0 with the MB sound card if I can figure that out.

I think I could do it with the 990 using the zone 2 outputs. I would have to leave it on all the time so my wife would not have to fool with it to watch Tv and it draws 40 watts. The Technics draws about 8 if I remember correctly. I had it lying around so it turned out to be a good solution.

Again, I would like to get the MB's sound card to do the 2.0 so I would not have to leave anything on.

Allen

This may not be the prettiest solution, but I would assume that your soundcard would still send out a signal to the headphone jack even while sending the spdif output.

First, the 990's second zone is an analog-only pre-amp, so no digital input will help. If you are just piping audio to the TV's speakers, I do wonder if garcianc2003 hasn't hit on a good idea - using the analog line output from the sound card to deliver audio to the TV. Then you can eliminate the Technics decoder and just use the 990 for surround duties. Sure, the sound card may not have as good a DAC as the Technics and almost certainly a step or three down from the 990, but in most cases the speakers in a TV won't be up to the task of showing the difference...

Not that it matters now that the problem is solved, but my best guess as to the cause would be SCMS (copy protection implemented in S/PDIF). Many devices implemented this specifically when dealing with a 44.1kHz signal. Naturally this shouldn't be the case, but I've heard of stranger things.

Glad to see it's resolved.

- Jason

I think it unlikely that it is copy protection given what the program is and the fact that to cure it I went to a more bit pure less processed configuration.

In terms of having the sound card put out analog as well as spdif, I would love it. That is what I have been unable to do. The headphone jack is dead when the sound card is set to spdif.

Since the 990 second zone will not decode spdif, I will have to keep the second decoder until someone figures out how to make the sound card put out spdif and analog.

Thanks all for the replies.

Allen