Are these digital out measurements decent enough? (95db SINAD)

[audiomaestro]

I'm not good in reading measurements, but I saw JDSLabs measured an LG TV's optical output and below are the results.

My question is. Is this level of performance on the digital out going to be audible? I plan on sending the digital out to an SMSL DAC.

LG 50UN7300PUF Optical S/PDIF Output @ 48 kHz input: 95 dB

 

[kemmler3D]

I'm not good in reading measurements, but I saw JDSLabs measured an LG TV's optical output and below are the results.

My question is. Is this level of performance on the digital out going to be audible? I plan on sending the digital out to an SMSL DAC.

LG 50UN7300PUF Optical S/PDIF Output @ 48 kHz input: 95 dB

More distortion than I would want to see but anything -95dB below the signal is really, truly hard to hear. Nothing serious to worry about here at all.

 

[formdissolve]

This has been discussed before, but that noisy output on TVs can cause intermittent dropouts with ESS-based DACs. If your SMSL DAC allows you to change the PLL settings, then you should be fine.

Noisy digital audio on LG TVs

Dear audio science enthusiasts, I recently got one of those popular LG C1 TVs. Since I only have a stereo system, but several HDMI sources plus using the TV's apps, I went the easiest audio route for my setup: (source) -> TV -> optical out (PCM) -> DAC -> analog Preamp As I realized only after...

www.audiosciencereview.com

 

[DVDdoug]

And, it's about as good as you can get a 16-bits (quantization noise), about "CD quality".

Dropouts and glitches are a different story...

 

[amirm]

It seems quite glitchy as they explain in FAQ and show in video:

That switching back and forth may be audible.

 

[Sokel]

And, it's about as good as you can get a 16-bits (quantization noise), about "CD quality".

Dropouts and glitches are a different story...

If the same conditions were also used at the AsRock Motherboard Optical S/PDIF Output measurement which follows that's not 16-bits down there,it's 24.
That's a horrible performance for digital.

 

[kemmler3D]

Q) what LG TV do you have or intend to buy?

I have a OLED55CXPUA (CX) and have used it with a few DACs over optical, with no glitches.

 

[amirm]

That's a horrible performance for digital.

HDCP over HDMI (or IP streaming) copy protection mandates 16 bit/48 kHz maximum resolution for any digital output. So they may be doing that to every signal coming in, copy protected or not.

 

[AnalogSteph]

HDCP over HDMI (or IP streaming) copy protection mandates 16 bit/48 kHz maximum resolution for any digital output.

*insert rant about stupid artificial restrictions here*

These sure look a lot like the "WMP burn with normalization turned on" results to me. So yeah, simple 16-bit truncation seems likely.

 

[audiomaestro]

This has been discussed before, but that noisy output on TVs can cause intermittent dropouts with ESS-based DACs. If your SMSL DAC allows you to change the PLL settings, then you should be fine.

Noisy digital audio on LG TVs

Dear audio science enthusiasts, I recently got one of those popular LG C1 TVs. Since I only have a stereo system, but several HDMI sources plus using the TV's apps, I went the easiest audio route for my setup: (source) -> TV -> optical out (PCM) -> DAC -> analog Preamp As I realized only after...

www.audiosciencereview.com

I saw that thread, but the part which was lacking was whether or not the "noise" was audible. I will make sure the DAC I purchase will have PLL settings, just in case I encountered drop outs. I'm not really worried about drop outs, just whether or not the optical out being noisy is audibly detectable by a set of ears.

 

[audiomaestro]

Q) what LG TV do you have or intend to buy?

I have a OLED55CXPUA (CX) and have used it with a few DACs over optical, with no glitches.

I have the OLED65GXPUA, which is basically the same internals as your CX. I believe the only difference is the shell.

 

[audiomaestro]

HDCP over HDMI (or IP streaming) copy protection mandates 16 bit/48 kHz maximum resolution for any digital output. So they may be doing that to every signal coming in, copy protected or not.

For HDMI connected devices (Apple TV 4K or PC) If I set my HDMI input to bitstream and the optical output to pass through, it can deliver lossless "untouched" 24 bit audio to a DAC. I'm thinking this would bypass the "noisy" degration that otherwise takes place at the optical out? Does that make any sense?

 

[kemmler3D]

I saw that thread, but the part which was lacking was whether or not the "noise" was audible. I will make sure the DAC I purchase will have PLL settings, just in case I encountered drop outs. I'm not really worried about drop outs, just whether or not the optical out being noisy is audibly detectable by a set of ears.

Unlikely in normal listening scenarios. In a realistic use case, you'd have to be cranking a classical recording up extremely loud, during a very quiet passage, to maybe possibly hear something.

 

[VintageFlanker]

I measured way (like waaay) better performance out of the Toslink of my LG OLED C2. I just need to find back the measurements...

Edit : here they are :

WiiM Ultra

What are the chances of the WiiM Ultra sounding as good as this $95K MSB DAC?

www.audiosciencereview.com

 

[audiomaestro]

Unlikely in normal listening scenarios. In a realistic use case, you'd have to be cranking a classical recording up extremely loud, during a very quiet passage, to maybe possibly hear something.

That's good news. I was worried the music would be audibly degraded during typical volume levels. Seems I have nothing to worry about.

 

[audiomaestro]

I measured way (like waaay) better performance out of the Toslink of my LG OLED C2. I just need to find back the measurements...

Edit : here they are :

WiiM Ultra

What are the chances of the WiiM Ultra sounding as good as this $95K MSB DAC?

www.audiosciencereview.com

Very interesting. The JDSLabs measurement was for a budget priced LG LCD TV, so the OLED models may have better measuring DAC's, but I did see CX, C1, and C2 owners complaining about dropouts in reddit, though.

Is it possible for a DAC which measures good to still have dropouts? If not, it would seem there's a DAC lottery happening with the OLED models.

 

[kemmler3D]

Is it possible for a DAC which measures good to still have dropouts?

Sort of, kind of.


It's actually not the DAC but just the digital audio output (SPDIF) being poorly implemented with a lot of jitter. This makes it hard for some DACs to keep a lock on the signal because the timing of the samples is all over the place. At some point they can't keep up and you get a dropout.


This can also hurt measurements, so a digital output with a lot of jitter also won't really measure truly well.

This is not to say it will be clearly audible, either.

There are other ways dropouts might occur (buffer underruns with high sample rates or something, network problems with the WiFi, etc.) so it's possible the complaints on Reddit were not from the same cause.

 

[VintageFlanker]

so the OLED models may have better measuring DAC'

That's digital output which is measured. DAC has nothing to do with it.

What @kemmler3D said :

It's actually not the DAC but just the digital audio output (SPDIF) being poorly implemented with a lot of jitter. This makes it hard for some DACs to keep a lock on the signal because the timing of the samples is all over the place. At some point they can't keep up and you get a dropout.

 

[audiomaestro]

That's digital output which is measured. DAC has nothing to do with it.

What @kemmler3D said :

Oops, Right. I meant the digital out, not the DAC.