Optical and Coax not working on NuWave DSD with cable TV terminal


#1

I use the NuWave DSD DAC with a USB input, through a Audience SE24 USB cable running to my Mac and Amarra. I also use the DAC with the coax RCA input, using a Transparent Audio Reference Digital Coax RCA cable running to my Oppo DVD/CD/Blueray player.

The Nuwave DSD signal is then flowing out through balanced interconnects to my Boulder integrated amp.

The only remaining source I have issues with is my cable TV terminal :

My cable TV terminal has several options for getting sound out:

1-Analog RCA: this is working great, but the way my system is configured and to gain better sound quality, I’d like my sound to go through the NuWave DSD DAC.

2-HDMI: This goes to a ceiling mounted projector. I do not use this for audio output.

3-Digital Coax RCA: I tried this audio output with the above mentioned cable that works fine with the DVD. No sound coming out when it is manually selected on the DAC and the NuWave DSD DAC does not recognize it when it powers up. The cable is good, it does work with the DVD and the DAC together…

4-Optical (tousling): This one is mind boggling. It is a new Silflex cable from Lifatec. When the cable is plugged into the cable tv terminal, I see its red light glowing on the other end where it is supposed to plug into the NuWave DSD DAC. So I know light is going to the DAC…This one, the NuWave seems to recognize briefly, but then goes blank. If I manually select it, it will stay on on this source, but again, no sound comes out…

I’ve been through several hours troubleshooting this with my cable provider, even with my Home Theatre techs and no one knows exactly what could be the problem. I’ve checked the cables on different sources and they work fine. The other sources themselves work fine. I rebooted the cable tv terminal several times with the HDMI cable unplugged, only the components inputs plugged in, no sound comes out of either the optical or digital outputs.

Please help!!


#2

Is the cable box set to output PCM? I learned the hard way that my FiOS boxes only output AC3, which the NuWave (or any other high-end DAC I’m familiar with) will not handle.


#3

Thanks for your reply steve. You are right about AC3. All the terminals they have use this. Is there a way to convert this to pcm so it can work with the dac? Don


#4

I don’t know of one but it you find one let me know. It has to be possible as my TV takes the signal from the cable box and puts out PCM (over Toslink in my case). That pretty much solves the problem for me. Have you tried that (TV has to be configured to output PCM, of course)?


#5

I do not have any TV. My HDMI video signal goes to a ceiling mounted projector. Before this situation, I ran RCA analog stereo outputs directly into my Boulder Integrated amplifier. But since I got the NUWave DSD DAC, I was hoping I could bypass the internal DAC of my cable tv terminal…I think I might have found something…Check this out:

http://www.ebay.com/itm/191199289003?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

What do you think?


#6

I’m confused by the description. Quoting:

"HDMI To Optical And S/PDIF Coaxial Audio Output
This HDMI audio converter can strip the compressed Dolby Digital, AC3 and DTS 5.1 digital audio from HDMI input and convert into optical audio format for further decoding by downstream device such as amp, A/V receiver or speaker system. All bitstream format such as Dolby 5.1, DTS 5.1 or LPCM 2-CH are supported by this unit.

"Its optical audio output supports 5.1 channels audio such as Dolby 5.1 or DTS 5.1 if the HDMI input feed has 5.1 channels embedded.


"Easy EDID Mode Switch
"
This converter unit has an EDID switch allowing users to configure the desired audio output format for further hookup with downstream audio device:

  • 5.1 CH Mode: Switch to 5.1CH/bitstream mode for Dolby 5.1, DTS 5.1 channels or LPCM 5.1 output through the optical port if the HDMI device supports such audio mode.
  • Auto Mode: Switch to auto mode for analog stereo output through 3.5mm stereo or RCA L/R connectors through the audio adapter supplied in the package."
If it is fed a 5.1 AC3 channel signal (embedded in HDMI), can it output LPCM stereo (which I assume you want for the DAC) or does it just strip the audio out of the HDMI stream and transmit 5.1 AC3, Dolby Digital or whatever format it was in over SPIF? The latter is what it looks like to me. It refers to LPCM 2 ch but that may just mean that it can deal with stereo LPCM input.

I’m no expert on TV audio formats and could be misreading this.


#7

When you get into audio-for-video land things get complicated quickly and stereo audio is the red headed step child.

I don’t know how different the HDMI de-embedders are, but many (most?) strictly do de-embedding: they send exactly whatever digital signal is there on down (but often only those that DRM allows, e.g. no DSD and possibly not protected hi-res.) The one’s I’ve seen personally don’t downmix the digital signal. Often they also have a stereo analog output, but I don’t know if it’s downmixed or not… Think of these like a cable adapter - no significant processing inside. They won’t get more for you than you would get from the TOSLink or S/PDIF output on the original device.

What’s worse, some sources don’t send correctly formatted stereo data over the connection at all. They send a two channel stream but not necessarily one formatted as two channels, just formatted like the first two channels of a multichannel stream… The NuWave will play this, but the DS and DS Jr won’t.

I looked at a few de-embedders and couldn’t figure out from the weird documentation what features were really there. I bought one but it doesn’t add any function to any of my devices.


#8

Altough sound quality is not on top of my list for the use of the cable tv terminal, it would be nice. Also, this need to have the optical sound out of my cable tv terminal into the PS Audio NuWave DSD dac is mostly a practical one. It would streamline the set up of my system, limit the number of interconnects needed and make it easier to use the system with its different sources. I ordered a different hdmi switch box that also separates the audio signal on Amazon. The seller promises it sends 2ch pcm out of the optical output. I will set it up and get back to all of you here with the final results.

One last thought or question: I agree that the audio-video universe is a whole different game. But apart from the royalties paid to Sony for the use of the ac3 format, why do hi-fi dac’s not support it? Is it because it affects 2ch stereo sound quality? It would be too expensive? Or maybe this need I have is part a small minority and not worth the effort?

thanks again for your input…


#9

ac3 is from Dolby not Sony :slight_smile: And yes, in general, royalties for the variety of audio for video formats can be onerous for smaller audio companies (tho just supporting Dolby might not cost too much.)

Anyway most video equipment can send out stereo PCM when configured correctly. Actually I’m surprised that someone would build a box that doesn’t support such a configuration. Often the downmixing to stereo is controlled by the same setup as that used to configure speaker sizes, speaker distance, etc. All of these functions aren’t otherwise needed in stereo DACs and often use video for setup…


#10

What is confusing me is that the cable tv terminal is already sending out 2ch stereo through L and R Analog RCA outputs…Is it so difficult to also send the converted 2ch stereo signal to the optical and digital outputs?


#11

One would think, but video equipment often does not care much, if at all, about two-channel PCM.


#12
donsounds said What is confusing me is that the cable tv terminal is already sending out 2ch stereo through L and R Analog RCA outputs...Is it so difficult to also send the converted 2ch stereo signal to the optical and digital outputs?
To do the correct thing for digital outputs for each of the sources with respect to digital rights management and licensing there are gobs of rules, special cases, etc. You can do what you want for analog outputs. You can usually do digital too if you keep it to 44.1k or 48k, but doing that down sample isn't free and it's not free to add configuration options... You might call your cable provider and ask how to get stereo PCM out. There might be an undocumented way, but even if not, if no one complains they're not going to add it back in.

#13

Hello everyone.

I do not want to make publicity for any third party vendor here, but I was able to fix my problem.

I asked several manufacturers of HDMI switches and sound extractors on Amazon and Ebay if their products supported 2 channel ppm on their optical output. Only one of them answered yes and I ordered the switch. After setting it up, everything works great. I am now able to listen to the sound of my cable tv terminal through the PS Audio NuWave DSD Dac in 2 ch stereo.

Thanks to everyone who answered and helped out as best they could. If you do not mind me posting the link to the device, let me know and I will do so…

Best regards to all,

Donald


#14

Post away I say. Could be useful to someone in a similar position.


#15

Yes, please let us know what worked.


#16

This is the device, but it is from the Canadian Amazon site…I am sure you can also find it on the american site:

https://www.amazon.ca/gp/aw/d/B01DD9X27M?pc_redir=T1


#17

I’m glad to hear it worked. From the description it just looked like another audio extractor to me.