TV / DAC issue (1 Viewer)

[Banzai]

I'm hoping someone more knowledgeable than I can help here:

I had an LG TV, connected via Toslink into a ZVOX 580. Worked great. Then about a year ago, I bought an SMSL M8 DAC to improve sound quality, worked flawlessly for 9 months. My girlfriend moves in, and her Sony TV (XBR55X800D) is larger, so I swap out the LG with the Sony, works straight away with the M8.

Then, the next day there is no sound and the M8 is saying No Signal. I check / reinsert cables, and finally get it working again, perhaps just a loose connection. Works fine again for a short while, then all of a sudden - no signal. It seems the input socket on the M8 might be loose as wiggling the Toslink cable in there seems to have some affect with the sound cutting in and out.

If I plug the Toslink cable straight into the ZVOX, works fine every time. I tried a different Toslink cable, same result. So, in thinking I might have a faulty M8, I exchange it for another unit, but this one also has the same issue. Hmmmmm.

So I just got hold of a Topping D30, but after connecting it, the abnormal signal light is on and the sound is just digital pulsing type noise.

I plug the Toslink cable back into the ZVOX - works instantly, back into the D30 - digital garbage. Swap out the cable, same result.

I feel like I'm missing something. I'd greatly appreciate any advice!

 

[Wayne A. Pflughaupt]

Can you actually hear an improvement in sound quality using the DAC? If not, ditch it. I’d be skeptical of an improvement in sound quality using an AVR and expensive speakers, and even more so with the ZVOX.

Regards,
Wayne A. Pflughaupt

 

[Banzai]

Can you actually hear an improvement in sound quality using the DAC? If not, ditch it. I’d be skeptical of an improvement in sound quality using an AVR and expensive speakers, and even more so with the ZVOX.

Regards,
Wayne A. Pflughaupt

Thanks for your response! Yes, I could hear a difference with the SMSL M8. Bass is more controlled, voices are clearer, overall more balanced. My girlfriend said that without the M8 it was like listening in a tunnel.

Any ideas on what I'm doing wrong with my setup?

 

[Wayne A. Pflughaupt]

Obviously, the Sony doesn’t like DAC’s. Don’t mean to be snide, but if every other combination works except Sony -> DAC-> ZVOX, then obviously the Sony is the problem. Can’t tell you why, though.

Regards,
Wayne A. Pflughaupt

 

[Banzai]

Ha - yeah.

I'm also at a loss as to why, I mean the ZVOX has a (lower quality) DAC in it that's doing the same job as the M8 or D30. The Sony likes THAT DAC, but not others.

Is this a common issue? I have a Lavry DAC in my home studio, there are no RCA outs to feed the ZVOX otherwise would have tried that, but my point is that I've not had issues connecting that to anything ever over the years. Do other people report seemingly random compatibility issues with consumer level Optical connects?

Toslink Out to Toslink In should just work, no ?

 

[Wayne A. Pflughaupt]

Yes, Toslink in and out should work. I’ve never heard of any other issues with Toslink like this.

Regards,
Wayne A. Pflughaupt

 

[Banzai]

Yes, Toslink in and out should work. I’ve never heard of any other issues with Toslink like this.

Regards,
Wayne A. Pflughaupt

Well that's good to know, thank you, and I suppose the chance of me having 3 faulty DACs (2 M8s one D30) is pretty low, although not impossible.

I'm still not convinced I'm not making a mistake somewhere

 

[Banzai]

I found the problem, and I have a workaround, so I wanted to update this thread to help others if they experienced the same.

When told to turn off the TV speakers, it seems the Sony is outputting Dolby Digital, but both the DACs are expecting PCM. The ZVOX supports Dolby, hence why no issue there.

So far, the only way I've found to force the Sony into outputting PCM is to turn back on the TV speakers but set the volume to zero. It's not ideal, as you can't use the TV remote anymore to control volume. But it works....

If there's a way I can force the TV to output PCM and also have the speakers set to off, it would be perfect, but Sony support seems no help....

https://community.sony.com/t5/Television-General/PCM-Out/m-p/494416/highlight/true#M12035