LG TVs Optical Audio Output Issue (poll)

Have you experience audio drop-outs with an LG TV when using optical?

  • Yes

  • No


Results are only viewable after voting.

ec295

Standard Member
Hello everyone, I'm new here but have been following this particular thread (and a few others) with interest. I have an LG OLED 48C1 and I've been having exactly the same problems as other members have described when using the LG's optical/Toslink out into a Cyrus 82 DAC QXR. The dropouts are only very brief, they happen a few times an hour at most, and only on Freeview broadcast TV.

The consistency with which this issue is affecting other users with high-end DACs is too much of a coincidence, not least because my Cyrus is also based on an ESS chip.

I've written to Cyrus to ask whether there might be a fix along the lines of the one offered to Cambridge Audio, Quad and Audiolab customers, so let's see what happens. In the meantime, I wanted to ask whether the suggestion above of adding the iFi SPDIF Purifier actually worked? @DrDarren @ostewart (or anyone else) could you update us? If the problem is jitter and noise, a reclocker like the iFi would surely help or potentially eliminate the problem altogether? It might also improve the sound more generally given that TVs are well-known for having rubbish optical/Toslink connection.

What do people think? Worth a shot?
 
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ec295

Standard Member
Incidentally, I tried a cheap HDMI ARC extractor from Amazon (Prozor), and the same problems arose. I had it set up with an HDMI 2.0 cable from HDMI ARC to ARC extractor HDMI in, then ARC extractor optical/Toslink out to optical/Toslink in on the Cyrus. I had hoped that the signal coming out of the ARC port would be different to the one coming out of the optical/Toslink port on the back of the LG, but it seems not (or, if it is, it's affected by the same problem).

Still a bit perplexed as to why I don't get any audio dropouts or glitches via the embedded streaming apps on the TV (eg. Netflix, iPlayer). Is it encoded differently?
 
I have had similar problems with toslink optical connections to a dac and these have in the main been related to a poor sync quality from the source, This was shown by connecting the optical lead through a Apogee Big Ben wordclock and watching the sync quality changing from narrow to wide and sometimes loosing sync alltogether during use . Some dac input receivers have a wider sync tolerance than others. In general terms Toslink optical connections are known to be a poor type of connection.
 

ec295

Standard Member
Yes, @mike bearne, that's been my sense with Toslink, but I'm stuck using it here.

When you say you had "similar problems" are you talking specifically about a 2021 LG OLED TV or just recent Smart TVs in general? Also, I presume the Apogee Big Ben sorted whatever problems you had - it's a pretty high-end reclocker! If so, this would bode well for the purchase of an iFi reclocker.
 

Lapstre

Active Member
Incidentally, I tried a cheap HDMI ARC extractor from Amazon (Prozor), and the same problems arose. I had it set up with an HDMI 2.0 cable from HDMI ARC to ARC extractor HDMI in, then ARC extractor optical/Toslink out to optical/Toslink in on the Cyrus. I had hoped that the signal coming out of the ARC port would be different to the one coming out of the optical/Toslink port on the back of the LG, but it seems not (or, if it is, it's affected by the same problem)
Been down the same frustrating journey the past 2 weeks. I've tried 2 prozor convertors and 1 from another brand. No luck. Coax output doesn't seem to help either. Do let me know in case the reclocker helps. Put me off picking up an LG OLED in the future.
 

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ec295

Standard Member
Been down the same frustrating journey the past 2 weeks. I've tried 2 prozor convertors and 1 from another brand. No luck. Coax output doesn't seem to help either. Do let me know in case the reclocker helps. Put me off picking up an LG OLED in the future.
Sorry to hear that. I think there's a problem with all the digital sound outputs of the TV, or perhaps the digital processing inside the TV itself. What brand of DAC are you using? And do you get the problem with all sources or just with broadcast TV (Freeview)? I don't get it when using the TV's inbuilt apps like iPlayer or Netflix.
 
Yes, @mike bearne, that's been my sense with Toslink, but I'm stuck using it here.

When you say you had "similar problems" are you talking specifically about a 2021 LG OLED TV or just recent Smart TVs in general? Also, I presume the Apogee Big Ben sorted whatever problems you had - it's a pretty high-end reclocker! If so, this would bode well for the purchase of an iFi reclocker.
I am using a LG CX (n0 soundbar involved) and I actually had problems with the Big Ben when connected and it showed the sync dropping at various times when watching tv programs direct and when using my nvidia shield hdmi connected (this maybe related to the age of the Big Ben and the electronics inside which must be at least 10yrs old) . When I connect my RME dac direct via the optical cable from the tv there are no problems with sync or dropouts either using direct tv or via the nvidia shield, this I put down to a much more recent design with better chips etc which have a much wider sync tolerance than the Big Ben.
 

ec295

Standard Member
I am using a LG CX (n0 soundbar involved) and I actually had problems with the Big Ben when connected and it showed the sync dropping at various times when watching tv programs direct and when using my nvidia shield hdmi connected (this maybe related to the age of the Big Ben and the electronics inside which must be at least 10yrs old) . When I connect my RME dac direct via the optical cable from the tv there are no problems with sync or dropouts either using direct tv or via the nvidia shield, this I put down to a much more recent design with better chips etc which have a much wider sync tolerance than the Big Ben.
Interesting, thanks.

I don't actually think age has much to do with it. On the contrary, the incompatibility seems to lie with fairly new (less than 3 years old) ESS Sabre chips and DACs that are manufactured using this architecture. These clearly provide excellent performance but are generally set to have very low jitter tolerance. Hence why Quad, Cambridge Audio and others whose DACs have these chips now offer the possibility of relaxing jitter tolerance slightly (see above in this thread). Ironically, those who have older DACs generally don't get any issues.
 

Lapstre

Active Member
Sorry to hear that. I think there's a problem with all the digital sound outputs of the TV, or perhaps the digital processing inside the TV itself. What brand of DAC are you using? And do you get the problem with all sources or just with broadcast TV (Freeview)? I don't get it when using the TV's inbuilt apps like iPlayer or Netflix.
I picked up a SMSL M500 with ES9038PRO. The firmware version I have does not have the ability to adjust the DPLL. I tested with the inbuilt Netflix and Spotify, didn't test with Freeview though...
 

Nocturnal

Member
As a new owner of an Arcam SA10 and using optical out from my LG TV, I had to set the PLL to wide also, didn't have to do this on my Schiit Modi 3.
Congratulations on the SA10 except you won't hear how good it actually is until you use other sources or DACs as the optical feed into the amplifier from an LG TV results is pretty poor (by Arcam standards) results (but good enough to watch Countdown on).

I use an Arcam CDS27 network streamer with it, and recently got an Ifi Zen DAC Signature to take over media playing duties via USB from my Mac M1 Mini and avoiding the HDMI-LG-TV- Toslink-SA10 connection.

PS It was probably my post about the original SA10 LG TV drop'out problem or one of the earliest from around this time last year or so.

I have never ever liked Toslink, I always considered it the worst sounding and the connectors must have came from the same design house as our illogical recycling bin system.
 

ec295

Standard Member
An update at my end if anyone is interested:

- Cyrus have offered me a software update to relax the jitter bandwidth tolerance on my 82 DAC QXR (they do this on the optical inputs, not the coaxial ones). The only snag is that this has to be done in the factory, so I've had to send the unit off for the upgrade. Good customer service, though, and let's hope it fixes the issue. According to their research, the worst offender when it comes to dropouts over optical is the Sky Q box, but their response really confirms what this thread suggests, namely that it's all about jitter tolerance and ESS Sabre chips.

- The iFi SPDIF iPurifier2 that I bought didn't solve the dropout problem (I still don't fully understand why), but it did make an audible improvement to the TV output sound quality. I was very much getting ready to return it to Amazon, but I might keep it. If you've already spent money on a high-end DAC, the iPurifier is a nifty and relatively inexpensive way to upgrade the sound from a digital source. In fact, it reminds me of the difference a good pair of interconnects could make back in the day of analogue inputs...
 

Nocturnal

Member
An update at my end if anyone is interested:

- Cyrus have offered me a software update to relax the jitter bandwidth tolerance on my 82 DAC QXR (they do this on the optical inputs, not the coaxial ones). The only snag is that this has to be done in the factory, so I've had to send the unit off for the upgrade. Good customer service, though, and let's hope it fixes the issue. According to their research, the worst offender when it comes to dropouts over optical is the Sky Q box, but their response really confirms what this thread suggests, namely that it's all about jitter tolerance and ESS Sabre chips.

- The iFi SPDIF iPurifier2 that I bought didn't solve the dropout problem (I still don't fully understand why), but it did make an audible improvement to the TV output sound quality. I was very much getting ready to return it to Amazon, but I might keep it. If you've already spent money on a high-end DAC, the iPurifier is a nifty and relatively inexpensive way to upgrade the sound from a digital source. In fact, it reminds me of the difference a good pair of interconnects could make back in the day of analogue inputs...
Good of Cyrus indeed but wow what a hassle and then both opticals are left in a wide PLL state (not sure if you care though if only used for TV). I'm glad Arcam had the audacity to be able to toggle PLL.

As for the ipurifier, well it simply does not work then as IfI claim or certainly not in your system.

I got the IFI Xpower supply along with their DAC Signature, that is £109 alone to buy separately but I've not tried the DAC without it, however it looks so nice it has got to work ☺️. Better power supplies almost always have a significant part to play in audio quality.
 

ec295

Standard Member
Good of Cyrus indeed but wow what a hassle and then both opticals are left in a wide PLL state (not sure if you care though if only used for TV). I'm glad Arcam had the audacity to be able to toggle PLL.

As for the ipurifier, well it simply does not work then as IfI claim or certainly not in your system.

I got the IFI Xpower supply along with their DAC Signature, that is £109 alone to buy separately but I've not tried the DAC without it, however it looks so nice it has got to work ☺️. Better power supplies almost always have a significant part to play in audio quality.
Yes, having to send any hifi back to the factory is always a bit terrifying. I keep thinking it'll get too cold in transit or some such nonsense! It's a shame this Cyrus model is not user upgradeable - that would save so much hassle.

I use the coaxial digital inputs for my "proper" hifi equipment (streamer, CD player), so I'm not too fussed that the optical inputs will be set to wide PLL. The dropouts are much more annoying than a marginal loss of quality (which I'm not sure will be audible, tbh). Again, though, it would be nice to have something I could toggle myself, like on the Arcam.

The iPurifier is definitely doing something. The sound is cleaner, tighter and tauter with it in as opposed to when it's out. No doubt this is all due to the circuitry and the stable power supply, which sorts out some of the mess produced by the TV. So perhaps the dropouts are actually being "passed through" to the DAC since the iPurifier doesn't upsample the signal? Or perhaps there's so much jitter from the TV output that the iPurifier can't clean it all up? Since the dropouts are inconsistent and pretty random, I can't be sure that the iPurifier has made no difference to the dropout issue. All I can say is that it hasn't solved it completely. I might ask iFi and/or Cyrus what their theory is (but only when I can confirm that Cyrus's fix actually fixes the problem!)

I'm sure your iFi power supply is doing something! :) What I like about iFi is that they offer audiophile solutions without paying silly money. Having only recently purchased an amp with a DAC, I'm a bit new to the digital game. I used to have an analogue-only amp, so I was focused on analogue accessories. But it's nice to see which accessories add value in a digital environment, too.
 

Nocturnal

Member
Yes, having to send any hifi back to the factory is always a bit terrifying. I keep thinking it'll get too cold in transit or some such nonsense! It's a shame this Cyrus model is not user upgradeable - that would save so much hassle.

I use the coaxial digital inputs for my "proper" hifi equipment (streamer, CD player), so I'm not too fussed that the optical inputs will be set to wide PLL. The dropouts are much more annoying than a marginal loss of quality (which I'm not sure will be audible, tbh). Again, though, it would be nice to have something I could toggle myself, like on the Arcam.

The iPurifier is definitely doing something. The sound is cleaner, tighter and tauter with it in as opposed to when it's out. No doubt this is all due to the circuitry and the stable power supply, which sorts out some of the mess produced by the TV. So perhaps the dropouts are actually being "passed through" to the DAC since the iPurifier doesn't upsample the signal? Or perhaps there's so much jitter from the TV output that the iPurifier can't clean it all up? Since the dropouts are inconsistent and pretty random, I can't be sure that the iPurifier has made no difference to the dropout issue. All I can say is that it hasn't solved it completely. I might ask iFi and/or Cyrus what their theory is (but only when I can confirm that Cyrus's fix actually fixes the problem!)

I'm sure your iFi power supply is doing something! :) What I like about iFi is that they offer audiophile solutions without paying silly money. Having only recently purchased an amp with a DAC, I'm a bit new to the digital game. I used to have an analogue-only amp, so I was focused on analogue accessories. But it's nice to see which accessories add value in a digital environment, too.
An IFI guy who I assume works for them regularly replies on this forum, he asked me to post on what I thought of the Zen DAC Signature for example, so maybe he'll pick up your query?

As for IFI products, I've just Tidal and testing MQA masters with the Zen DAC Signature and while it sounds great in general in head to head testing it isn't in the same league as the Arcam CDS27 which presents a much grander sound stage, more depth, more slam in the bass and goes lower, the Arcam is also more revealing musical wise.

Considering the Arcam CDS27 cost an original £799 or so and Arcam sure knows how to make great DAC stages it is no surprise. You can pick them up used on eBay from around £230 - £350 nowadays and I wouldn't part with mine even if it doesn't support MQA.

Hope you are getting your Cyrus back soon and the PLL modification worked.
 

ec295

Standard Member
An IFI guy who I assume works for them regularly replies on this forum, he asked me to post on what I thought of the Zen DAC Signature for example, so maybe he'll pick up your query?

As for IFI products, I've just Tidal and testing MQA masters with the Zen DAC Signature and while it sounds great in general in head to head testing it isn't in the same league as the Arcam CDS27 which presents a much grander sound stage, more depth, more slam in the bass and goes lower, the Arcam is also more revealing musical wise.

Considering the Arcam CDS27 cost an original £799 or so and Arcam sure knows how to make great DAC stages it is no surprise. You can pick them up used on eBay from around £230 - £350 nowadays and I wouldn't part with mine even if it doesn't support MQA.

Hope you are getting your Cyrus back soon and the PLL modification worked.
Fingers crossed. Getting the Cyrus back on Monday and will give it a lengthy test (great excuse to watch some telly on the otherwise amazing LG OLED TV...)

I'll also report back on the iPurifier. What's the username of the iFi guy on here? I can tag him or ask him directly.
 

Nocturnal

Member
Fingers crossed. Getting the Cyrus back on Monday and will give it a lengthy test (great excuse to watch some telly on the otherwise amazing LG OLED TV...)

I'll also report back on the iPurifier. What's the username of the iFi guy on here? I can tag him or ask him directly.
This fellow click on the link

Ifi audio member
Yes I just got the LG OLED 48" A version for my mother on Black Friday and she loves it. I have a cheaper LG 43" non-oled and it is still impressive but glad it is not an oled as it gets used for static computer screen use, I'm sure you know about burn in issues.

The Zen USB DAC is great for watching films from the Apple M1 mini so I'm keeping it for that alone.
 

ec295

Standard Member
This fellow click on the link

Ifi audio member
Yes I just got the LG OLED 48" A version for my mother on Black Friday and she loves it. I have a cheaper LG 43" non-oled and it is still impressive but glad it is not an oled as it gets used for static computer screen use, I'm sure you know about burn in issues.

The Zen USB DAC is great for watching films from the Apple M1 mini so I'm keeping it for that alone.
Cheers! Here's hoping @iFi audio's tech team have some thoughts about this. I'm mostly just curious.
 

ec295

Standard Member
Hi folks,
here is the so-called iFi guy. How can I help you?
Haha, hello!

So, as you'll see, this thread is all about problems using the optical out of LG OLED TVs into high-end DACs that have ESS Sabre chips. Various users with DACs from manufacturers like Arcam, Audiolab, and Cambridge Audio have experienced dropouts or loss of sync when connecting their LG TV's optical out to their DACs. In some cases, this has been pretty severe; in others, like mine, it's been fairly infrequent. But it's enough to be very annoying.

Over time, almost all the manufacturers in question have recognised this problem (it seems to happen with many other such devices, like Sky Q boxes) and identified the cause, which is the jitter reconstruction technology used in ESS chips. The solution, it seems, is to increase the jitter tolerance by setting the PLL bandwidth to "Wide". Many manufacturers have now offered this possibility via firmware updates, and this has largely fixed the issue. In my case, I had to send my Cyrus 82 DAC QXR back to the manufacturer to get the firmware update, but I'm hoping this will solve the problem as it has for others (I just got the unit back today - so far, so good!).

Anyway, where iFi comes in is that, as part of my attempts at troubleshooting the dropout issue in the first place, I purchased an iFi SPDIF iPurifier2. I was hopeful that, with the iPurifier in place, the signal would be clean enough to stop the dropouts occurring, even without needing to set the PLL bandwidth to "Wide". Unfortunately, as I mentioned further up this thread, that's not what happened. This is what I said:

"The iPurifier is definitely doing something. The sound is cleaner, tighter and tauter with it in as opposed to when it's out. No doubt this is all due to the circuitry and the stable power supply, which sorts out some of the mess produced by the TV. So perhaps the dropouts are actually being "passed through" to the DAC since the iPurifier doesn't upsample the signal? Or perhaps there's so much jitter from the TV output that the iPurifier can't clean it all up? Since the dropouts are inconsistent and pretty random, I can't be sure that the iPurifier has made no difference to the dropout issue. All I can say is that it hasn't solved it completely."

My question to you, then, is: if the iPurifier was cleaning and reclocking the signal, why were the dropouts still occurring? Shouldn't they have stopped? More generally, what is the interaction between the iPurifier and a DAC?

I'm genuinely curious about the answer to this question, so feel free to be as technical as you want!
 

ostewart

Well-known Member
Yes, having to send any hifi back to the factory is always a bit terrifying. I keep thinking it'll get too cold in transit or some such nonsense! It's a shame this Cyrus model is not user upgradeable - that would save so much hassle.

I use the coaxial digital inputs for my "proper" hifi equipment (streamer, CD player), so I'm not too fussed that the optical inputs will be set to wide PLL. The dropouts are much more annoying than a marginal loss of quality (which I'm not sure will be audible, tbh). Again, though, it would be nice to have something I could toggle myself, like on the Arcam.

The iPurifier is definitely doing something. The sound is cleaner, tighter and tauter with it in as opposed to when it's out. No doubt this is all due to the circuitry and the stable power supply, which sorts out some of the mess produced by the TV. So perhaps the dropouts are actually being "passed through" to the DAC since the iPurifier doesn't upsample the signal? Or perhaps there's so much jitter from the TV output that the iPurifier can't clean it all up? Since the dropouts are inconsistent and pretty random, I can't be sure that the iPurifier has made no difference to the dropout issue. All I can say is that it hasn't solved it completely. I might ask iFi and/or Cyrus what their theory is (but only when I can confirm that Cyrus's fix actually fixes the problem!)

I'm sure your iFi power supply is doing something! :) What I like about iFi is that they offer audiophile solutions without paying silly money. Having only recently purchased an amp with a DAC, I'm a bit new to the digital game. I used to have an analogue-only amp, so I was focused on analogue accessories. But it's nice to see which accessories add value in a digital environment, too.

It is 100% down to the TV outputting really high jitter and nothing to do with the iFi iPurifier not doing it's job.

I can now confirm the brand I was talking to about the dropout issue was JDS Labs and they have posted up some info about it here: JDS Labs - Troubleshooting
 

ec295

Standard Member
It is 100% down to the TV outputting really high jitter and nothing to do with the iFi iPurifier not doing it's job.

I can now confirm the brand I was talking to about the dropout issue was JDS Labs and they have posted up some info about it here: JDS Labs - Troubleshooting
Thanks for this excellent explanation, courtesy of JDS Labs's tech team. It tallies exactly with what you said at the top of the thread (in fact, I think you copied parts of the FAQ into one of your posts).

However, this explanation still leaves me wondering why, if the iPurifier was regenerating and reclocking the signal, the dropouts were still occurring? Shouldn't the iPurifier have "cleaned" up the noise and transients in the process of regenerating the signal? It may be that I'm missing something obvious here.
 
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ostewart

Well-known Member
Thanks for this excellent explanation, courtesy of JDS Labs's tech team. It tallies exactly with what you said at the top of the thread (in fact, I think you copied parts of the FAQ into one of your posts).

However, this explanation still leaves me wondering why, if the iPurifier was regenerating and reclocking the signal, the dropouts were still occurring? Shouldn't the iPurifier have "cleaned" up the nose and transients in the process of regenerating the signal? It may be that I'm missing something obvious here.

I don't think the iPurifier can fix such a severe fault from the source - there is no way to correct that amount of jitter and noise , it would need to be fixed on the actual TV side (internally by LG).

Also I copied parts from my initial emails with JDS Labs, which ended up in their FAQ which they posted publicly after LG failed to address the issue.
 

ec295

Standard Member
I don't think the iPurifier can fix such a severe fault from the source - there is no way to correct that amount of jitter and noise , it would need to be fixed on the actual TV side (internally by LG).

Also I copied parts from my initial emails with JDS Labs, which ended up in their FAQ which they posted publicly after LG failed to address the issue.
That sounds entirely plausible. I will be curious to know whether @iFi audio can confirm this or give more detail.

FWIW, when I contacted Cyrus, they were also aware of this problem - in their view, Sky Q boxes were the worst culprits.
 

wood1000

Novice Member
I set up a new LG 48C1 on Christmas morning and connected it to my Arcam SA10 via optical and get the issues described. Random split second drops across Apple TV , Xbox and PS4 pro. I had no issues at all with a 2017 Sony LED. Changing the Arcam's PLL sttings to wide did not resolve the issue (although it may have dropped less) . I have set up my old Arcam IRdac ( Burr Brown Dac ) and the issue has gone away. Thanks to this thread for getting me on the right track !
 

Nocturnal

Member
I set up a new LG 48C1 on Christmas morning and connected it to my Arcam SA10 via optical and get the issues described. Random split second drops across Apple TV , Xbox and PS4 pro. I had no issues at all with a 2017 Sony LED. Changing the Arcam's PLL sttings to wide did not resolve the issue (although it may have dropped less) . I have set up my old Arcam IRdac ( Burr Brown Dac ) and the issue has gone away. Thanks to this thread for getting me on the right track !
As you may know the issue is with the Sabre chipsets, not Burr Brown.

I have an ordinary LED backlit LG TV (modern 2020) model and changing the PLL to wide on Arcam SA10 solved it, I'd assume that LG are using the same crappy Toslink electronics on both these TVs so strange you still have an issue unless the jitter on your new OLED model is even worse again.

I find the Toslink link from the LG TV to the SA10 gives a crap sound anyway, I used to connect my M1 Mac Mini via the LG HDMI this way and the sound was so underwhelming I ended up buying a Zen Signature USB DAC.

Your irDAC will be superior to the SA10 built-in DAC regardless. You may find like me you will never use the built-in DAC again but doesn't matter as the SA10 is a great amplifier deserving a better DAC anyway.
 

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