USB -> SPDIF solutions?

evoisard · October 8, 2020 at 5:47 PM

Hi,

I've Libreelec 9.2.4 installed on my Intel NUC 10I5FN. I need an SPDIF audio output to feed my old Yamaha AVR.

I bought a Digitus DS-40132 HDMI audio extractor that's supposed to output analog and SPDIF audio, but for some reason it fails with my Samsung TV set: the HDMI signal is not detected properly. As it could be due to "plug&play" aspects of my "smart" TV, I'm looking for other solutions.

I googled for USB->SPDIF devices and their compatibility with Libreelec/Kodi and I've found a lot of contradicting things. In particular, I've read that USB to DAC/SPDIF was no longer supported in Libreelec/Kodi...

Is that true?

If not, can anyone recommend a good usb->spdif device that works, as from Libreelec 9.2.4?

Thanks in advance (and sorry if it's a recurring question)

Eric

**Da Flex** · October 9, 2020 at 9:25 PM Official Post

Quote from evoisard

...but for some reason it fails with my Samsung TV set: the HDMI signal is not detected properly. As it could be due to "plug&play" aspects of my "smart" TV, I'm looking for other solutions.

I don't think so. If it works without the extractor, it has to work with the extractor, too. That's just a pass-through function. If you still have guarantee, order a replacement.

The USB audio can fail on higher data rate (HD audio formats). So, the extractor solution should be preferred.

**zomboided** · October 9, 2020 at 10:31 PM

I used to have a lovely old Yamaha amp, sounded so good even after 20 years. The only solution I found was to do Pi to TV via HDMI, then optical out from the TV to the amp. I have a newish Sony TV and that seemed to work fine with DD5.1 and DTS, with pass through enabled in the relevant sound menu. Didn't work for the HD audio formats, but from memory those just got down sampled and I put up with it.

Also my experience was (and I can't remember how I did this)...if you try split the signal before it gets to the TV and the TV does a bunch of processing on the picture, then it can throw out the timing and the audio can be ahead of the video and you're forever fiddling with the offsets and it's never right.

lyoko · October 9, 2020 at 11:32 PM

External 5.1 Channel USB 2.0 Sound Card Optical Audio Adapter - Black - Free shipping - DealExtreme

this just works amazing, it has spdif-in, spdif-out, I didn't use these ports, but I'm using this sound card for the past 5 years, amazing.

librelec has no issues with this USB sound card, alsa detects, it appears in kodi system settings.

openbaffle · October 11, 2020 at 11:58 AM

Quote from evoisard

Is that true?

If not, can anyone recommend a good usb->spdif device that works, as from Libreelec 9.2.4?

Most of the USB to SPDIF converters work well, I have used dozens of converters none of them gave me any kind of problem.currently I am using MATRIX usb spdif. choose XMOS based chip.

evoisard · October 11, 2020 at 2:05 PM

Thanks for your answers!

I'm thinking my TV set (Samsung QE65Q60R) could be faulty because if I try my audio extractor with a simple PC monitor, it works, I get an image on the display. I also tried it on my TV with my BluRay player: my "smart" TV complains about an unknown source (on same HDMI port), but fiddling with the remote I can force it and finally get an image on TV. Yet, no spdif sound is extracted...

My extractor provides output drivers to b00st (censored??) output signals and allow longer hdmi cables. So it's not passive and it might be defective. I've obtained an RMA. I'll return it and try again with the replacement one...

On TV side, I tried the spdif output with passthrough function like on the Sony TV. I got audio on the AVR, but only 2-channels (i.e. Pro Logic and the like). I also tried the HDMI ARC output connected to my extractor just to get the spdif audio, without connecting the HDMI output. As expected it failed.

I'm please to hear that USB->SPDIF devices work with Kodi. Given the low price I think I'll order one like Iyoko as a plan B. Anyway, SPDIF as well as my Yamaha amp don't support HD audio so it's worth a try...

But, I also have in mind the fact that the obsolete element in my home system is the AVR. I'm currently struggling to have all my recent devices work with my old Yamaha. Maybe is it time to stop wasting money on thinkered solutions and shell out the money for a fully HDMI, beautiful new AVR...

**Da Flex** · October 11, 2020 at 6:54 PM Official Post

Sounds like a plan. Don't forget that HDMI will speed up data rate when connected to a 4K display. Make sure your HDMI cables can handle it. HDMI 2.0 and 2.1 standard cables are ready for that 4K data rate.

Your extractor has that little 5.1 / 2.1 channel switch - always test both modes.

noggin · October 14, 2020 at 4:51 PM

Also if you are running 4K then your audio extractor also needs to be 4K friendly - counterintuitive as this may seem. The reason for this is that HDMI audio is not carried separately to the video, it's actually embedded in the video signal (it's carried in the blanking period of the HDMI video signal where there isn't active video).

If you are running a higher data rate video signal (4:2:2 2160p60 for instance) then your extractor also needs to support the higher bandwidth.

**Da Flex** · October 14, 2020 at 6:52 PM Official Post

It looks like HDMI audio extractors with an audio channel switch are critical: 6ch audio over HDMI audio trouble.

Unfortunately the thread starter Anke doesn't talk a lot, so I'm still unsure what happens. Maybe a different extractor solves it.