Bartok and Rossini dac problem using optical connection

@Givara, based on James’ explanation of the issue, what you might want to try is an active TOSLink Repeater or Splitter; one that will regenerate your LG TV’s TOSLink signal, in the hopes that the regenerated signal is well within proper specs.

Something like this between your TV and your dCS;

There’re quite a few on Amazon. Make sure it’s an active unit, meaning it requires power, and not one of the passive optical splitters. Shouldn’t cost more than a couple of cups of Starbucks, so no real harm if it doesn’t work :crossed_fingers:t3: :grin:

Anup, that is such a creative suggestion. I really hope that it works for Givara and that adm95 who has the same difficulty with his LG TV gets to see your post.

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Whether or not this sort of device works will depend on if the repeater is reclocking the signal or simply “squaring” it.

Reclocking it, as the Oppo player seems to do, means that it is using a clock with a wider pull range and playing back the audio samples based on its own internal clock. This would make the samples more in time and mean the dCS unit would be able to lock to it. You’ll get some audio artefacts in the signal (dropped samples) but it will play back.

If the device is simply using a squaring circuit, it won’t be changing the timing of the signal, simply making sure that the optical equivalent of the output voltages are correct. It allows signals to be transmitted over larger distances. As it won’t be changing the timings of the signal at all, it won’t have an impact on the dCS unit being able to lock to the signal.

I’ve seen devices do both, so I couldn’t make any guarantees on whether one would work or not!

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All toslink spletters and repeaters that i found on internet do not have own clock

can u plz suggest a model that have a clock in it? only in Moscow i know 3-4 ppl having problems with DCS-LG and that could realy help us. OLED Lg tvs are so popular that this will not be such a rare problem for DCS customers

These two claim to reclock TOSLink inputs and might fit the bill. I have no personal experience with either, and not quite as low-cost as the Amazon units, but these might actually work I suppose. :crossed_fingers:t3:

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What superb suggestions @Anupc! This has inspired me to stage an experiment this weekend. I have an LG OLED monitor which is is now connected over HDMI to a Marantz pre/pro. The Marantz also hosts an Oppo 205, and the 4K boxes by Apple, Amazon, and Roku. This all feeds a 7-channel amp and separate in-wall speakers for home theater. The Oppo is also connected to the Vivaldi DAC via Toslink (for the occasional disc playback). I tested the sound in this configuration before I installed the clocks, and it seemed to work fine.

But now I want to try and see what happens when I simply run optical out of the LG into the Vivaldi, and what happens if I run optical out of the Marantz into the Vivaldi.

Imagine if it actually works without a problem, and then what? :rofl:

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would love to hear your outcome!

A brief explanation for my delay. I could not get Vivaldi DAC to lock on to the Toslink signal from the LG, but I cannot verify that is my actual outcome yet. I believe something about the HDMI path between the Oppo, the Marantz, and the LG was complicating the assessment. So, this weekend, I will remove the Oppo and Marantz from HDMI path altogether, connect an AppleTV to the LG directly via HDMI and see what I can hear.

I can now confirm my Vivaldi DAC locks on to the optical output from my LG TV (model 77EG9700-UA) with no problem (except that video and audio are not in sync, and there is insufficient flexibility in either the LG’s or AppleTV’s settings to correct it). Vivaldi screenshot below. image

So Greg, where does that leave us?

I think that it might indicate that the locking problem may lie not with the LG brand per se but with the 65C8 which is what I think both of the originators in this thread have.

Unfortunately even this information may be of little help. This is due to the fact that the large far eastern TV manufacturers do not necessarily make identical TVs for different markets even if they carry the same model number.

That still leaves you with the latency problem causing a lack of synch between video and audio. I vaguely recall seeing some black boxes that were supposed to deal with this issue years ago when reading some specialist Home Theatre mags. Haven’t seen one for years though so I have no idea if such things are still available.

I have a similar recollection Pete. I took a quick look, and could not find any though. The LG TV does have a sync adjustment, but it’s insufficient to get the audio in sync. It’s interesting that, in most home theater articles, the problem appears to be that the video lags the audio. [It’s also interesting that Toslink seemed to top the list of problem conduits.] My experience was that the audio severely lagged the video, by as much as a half second.

For me, this is not really a problem, because I prefer to run the TV separately through the pre/pro and the HT amps and in wall speakers. It’s nice to be able to play the Oppo through Toslink into the Vivaldi DAC for occasional disc playback, and that doesn’t require sync. But for folks who need this to work in order to integrate their video into their lovely dCS system, I am afraid I do not have a solution.

Should be “A” in the clock selection, whrn “M” selected oudio dropouts can happen every 20-40 mins in “A” dropouts happene every several minutes

Greg, was the TOSLink directly into your DAC or to the Upsampler? Did you try Clone-Mode (Upsampler) and Buffers Off (DAC)? That should minimise delays.

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Thanks for that. Toslink was into the DAC. Buffers were probably still on, but would that have mattered with optical straight into the DAC? I could check, but am unlikely to disconnect everything again to test anytime soon.

With the settings as visible in my pic, after 90+ minutes, there was not one moment of dropout. DAC never lost lock.

Yeah, it would, as much as 0.72s in added delay according to the Manual :slightly_smiling_face: Don’t think it’s worth your time to set it up and try again, but good for others as a reference.


Duh. I totally missed that. That’s actually encouraging to know. I had assumed the buffers would not matter as much going straight to the DAC. Sorry I missed that. Thanks.

UPDATE: turning the buffer off on the DAC solved the sync problem. There is a minor mismatch now that can be easily solved within the LG’s sync adjustment panel.

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I have not seen this topic before but would like to respond to it. I had the same problem with my “old” Rossini DAC. But even worse, my LG oled TV just wouldn’t play the sound at all. I got a constant on / off click from the DAC. I soon found out that the problem was with the TV. It has a bad digital signal. But then suddenly I thought of my Monarchy Audio DIP Combo reclocker/ upsampler (, and connected the TV’s optical output to the DIP Combo and XLR out to the DAC. Problem solved. But now it comes …
I have had the Vivali DAC for a few weeks now and of course I was curious if the same problem is present here. But no, no problems with playing optical with the same LG TV. I still use the DIP combo and now it gives a 24/96 signal to the XLR input of the DAC. I need the only optical input available for my wife’s digital tuner.

Well, Rossini DAC has no problems whatsoever with my Samsung TV using TOSlink. It presents a 24/48 signal… I do hear some clicking now and then when the broadcaster sends a “null” signal, but the sample rate is always the same.