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Toslink and Jitter

lewdish

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I've been looking into getting some Optical/Toslink Cables for a for a video VHS archival project. I want to use an external DAC instead of the one that's built into the VHS player and the only way to keep the data in digital is via Toslink to my DAC/AVR. I get that Jitter is irrelevant generally in modern cables but Toslink is an older technology and apparently far more prone to jitter due to optical data transfer.

I was looking to buy a few to test out. I know some folks here swear by Supra Cables being really solid quality. When looking into them they seem to guarantee 32 bit/384 kHz transfer (which I'm not even sure if Toslink is capable of outputting even that high out of most DACs) and claim to have the same performance as glass optical cables. That being said i've also found some glass cables that are cheaper than the Supra Cables, and beneath that in cost I've found most cables to just us regular plastic fibers for only a few bucks. I've also come across users online that say different cables cap out at different outputs and that bending too hard will induce significant jitter. This is the first time I've ever used optical out on any device to be honest not sure how much of it matters, however I do want to get the best quality out of transmission. Any guidance on this from other Optical output users?
 

AnalogSteph

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I want to use an external DAC instead of the one that's built into the VHS player
Uh, what? VHS audio is 100% analog (FM with bonus head switching noise). Do you mean the system that plays the archived captured VHS recordings?

Anyway, for short runs of a few feet the plastic fiber jobs are fine. The audibility threshold for jitter is also quite high, more so if the volume control follows the DAC so you don't need the last bit of dynamic range, and if you are still fussed about this a DAC using ESS chips is likely to be a good bet due to what amounts to built-in ASRC. DAC manufacturers have also come up with their own ways of jitter suppression though, particularly veterans in the professional space.
 
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lewdish

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Uh, what? VHS audio is 100% analog (FM with bonus head switching noise). Do you mean the system that plays the archived captured VHS recordings?

Anyway, for short runs of a few feet the plastic fiber jobs are fine. The audibility threshold for jitter is also quite high, more so if the volume control follows the DAC so you don't need the last bit of dynamic range, and if you are still fussed about this a DAC using ESS chips is likely to be a good bet due to what amounts to built-in ASRC. DAC manufacturers have also come up with their own ways of jitter suppression though, particularly veterans in the professional space.
I'm archiving into digital but the video & audio will be fed into an upscaler. The Toslink on my VCR is a digital out, so I wanted to run that into an external DAC that spits it out to RCA for the video upscaler card then into a capture card. All the VHS analog data will be converted to digital essentially by whatever ADC is in the upscaler and VCR.

Generally I get that Jitter is a non-issue for most cables, I've just read some users say that optical output just sounds really poor in comparison to all other cables as a result of the high level of jitter esp if the cable has lots of bends in it. Cool to know there's some sort of jitter mitigation built into ESS DACs though cause my DAC does use a fairly modern ESS chip.
 
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Trell

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I'm archiving into digital but the video & audio will be fed into an upscaler. The Toslink on my VCR is a digital out, so I wanted to run that into an external DAC that spits it out to RCA for the video upscaler card then into a capture card. All the VHS analog data will be converted to digital essentially by whatever ADC is in the upscaler and VCR.

Generally I get that Jitter is a non-issue for most cables, I've just read some users say that optical output just sounds really poor in comparison to all other cables as a result of the high level of jitter esp if the cable has lots of bends in it. Cool to know there's some sort of jitter mitigation built into ESS DACs though cause my DAC does use a fairly modern ESS chip.

An optical cable does not have to be very expensive, just of good quality.

With my RME Fireface UCX II there was a 2 meter long supplied optical cable (OKO200Pro - 2 meter) that costs $22 new from the US RME site. Works very well, as expected, and it's thin so I can roll it up as it's connected between my UCX II and my RME ADI-2 DAC FS that are stacked on top of each other.

Edit: I got a different cable than the one linked to that is shown as a replacement part for the supplied one which is 2.75 mm thick.


1668866386433.png
 
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lewdish

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An optical cable does not have to be very expensive, just of good quality.

With my RME Fireface UCX II there was a 2 meter long supplied optical cable (OKO200Pro - 2 meter) that costs $22 new from the US RME site. Works very well, as expected, and it's thin so I can roll it up as it's connected between my UCX II and my RME ADI-2 DAC FS that are stacked on top of each other.

Edit: I got a different cable than the one linked to that is shown as a replacement part for the supplied one which is 2.75 mm thick.


View attachment 244404

I wanna know how these Monoprice ones compare, they seem really "fancy" for the price, 10ft for $6, The build seems really extra, not even sure why there's all this insulation and shielding on it given that Toslink isnt affected by RFI/EMI.


1668868692242.png
 

Blumlein 88

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Check this post on the issue. Two different devices showing a J-test signal from Coax and Toslink for each. No difference in jitter. Coincidentally, I was using the very same Monoprice Toslink cable pictured in the above post. Toslink is fine and the cheaper cable is fine. The cable isn't the issue with jitter, the clock in use is. Some very early Toslink used marginal optical converters. Hasn't been an issue for a long time.

Also, the fancy Monoprice cable is just the same skinny black Monoprice Toslink with that silver techflex woven cover and big square covers over the ends.

 
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Ken Tajalli

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I still can not get my head around a VHS machine with digital out!
At any rate, I got a £3 TOSLINK from eBay, that looks good and operates flawlessly at 192kHz into two DACs from my PC. If the cable has any deficiencies, the first thing one would notice is that it would not work at 192kHz, which is the max. TOSLINK can work at.
So there you go! cheap ones are as good.
 

GeorgeBynum

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I wanna know how these Monoprice ones compare, they seem really "fancy" for the price, 10ft for $6, The build seems really extra, not even sure why there's all this insulation and shielding on it given that Toslink isnt affected by RFI/EMI.
A significant reason for the metal cover and thick jacket is to minimize sharp bends. It has no shielding benefit and they don't suggest that it does from my quick perusal.
 

Lambda

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I wanna know how these Monoprice ones compare, they seem really "fancy" for the price, 10ft for $6, The build seems really extra, not even sure why there's all this insulation and shielding on it given that Toslink isnt affected by RFI/EMI.
Its all complete BS. Get the Generic cable that looks like this:
40058_0.jpg

It’s gona be fine and the better looking ones are not better
 

sq225917

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There's loads of vhs dvd recorder combi players with digital outputs, hdmi and toslink
 
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lewdish

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There's loads of vhs dvd recorder combi players with digital outputs, hdmi and toslink
For archival purposes there's a few that stand out from the rest in terms of features that improve quality of playback and recording, most noticeably TBC. Only certain higher end and professional players would have this function built in. Almost all, if not all cheaper VCRs and combi-players never had this function and 1 or 2 very rare and expensive players with TBC had HDMI output. Toslink however was kinda all over the place, it could sometimes be found on high/low/and late era models. Mine does have toslink so that's what I am resorting to for my archiving.
 
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lewdish

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Its all complete BS. Get the Generic cable that looks like this:
40058_0.jpg

It’s gona be fine and the better looking ones are not better
Are they data/transfer capped? The Supra cable for example seems to claim that they transfer up to 32 bit 384 khz, where a lot of older Toslink posts I've read have said that diff cables cap at 16/24bit & between 48-96khz depending on the quality of the cable.
 

Trell

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Are they data/transfer capped? The Supra cable for example seems to claim that they transfer up to 32 bit 384 khz, where a lot of older Toslink posts I've read have said that diff cables cap at 16/24bit & between 48-96khz depending on the quality of the cable.

That generic optical cable looks like the one supplied with my RME UCX II audio interface.

SPDIF TOSLINK tops out at 24 bits/192 kHz, and CD quality is 16 bits/44.1 kHz. What kind of quality do you expect to get out from a VHS machine?
 
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Lambda

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Are they data/transfer capped? The Supra cable for example seems to claim that they transfer up to 32 bit 384 khz, where a lot of older Toslink posts I've read have said that diff cables cap at 16/24bit & between 48-96khz depending on the quality of the cable.
This is all marketing BS. don’t fall for any of this.
They will work exactly the same.

The cabel is never the limiting factor with reasonable length Toslink
 

restorer-john

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There's loads of vhs dvd recorder combi players with digital outputs, hdmi and toslink

But the VHS (tape) signal is not digitized. The outputs are just for the onboard DVD player's SPDIF.

You'd use an outboard capture card/usb to get the VHS video+audio into a PC.
 

Blumlein 88

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Are they data/transfer capped? The Supra cable for example seems to claim that they transfer up to 32 bit 384 khz, where a lot of older Toslink posts I've read have said that diff cables cap at 16/24bit & between 48-96khz depending on the quality of the cable.
Why do you care about higher transfer rates? Your source is the bottleneck. FM modulated striped audio on VHS tapes. It could have pretty good specs with head switching noise thrown on top. Most definitely doesn't exceed 16 bit or 48 khz in quality. So maybe 24 bit for convenience and headroom working with it, but there is no benefit to things like 32 bit or 384 khz considering your source. Pretty much any Toslink is good to 24 bit 96 khz so any more than that is overkill and of no benefit to you.

As for the VHS tapes do you plan to digitize them, turn them into DVDs or files like on DVD's? You don't need any high rate or special Toslink for that either.
 
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lewdish

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Why do you care about higher transfer rates? Your source is the bottleneck. FM modulated striped audio on VHS tapes. It could have pretty good specs with head switching noise thrown on top. Most definitely doesn't exceed 16 bit or 48 khz in quality. So maybe 24 bit for convenience and headroom working with it, but there is no benefit to things like 32 bit or 384 khz considering your source. Pretty much any Toslink is good to 24 bit 96 khz so any more than that is overkill and of no benefit to you.

As for the VHS tapes do you plan to digitize them, turn them into DVDs or files like on DVD's? You don't need any high rate or special Toslink for that either.
Just curious just want to know if they could be tested for the purpose, also I don't really plan on really ever buying any more Toslinks since its such a limited use case, so might as well find the best one I could find. I plan to archive them into digital files for my home NAS. I may also try to remaster/mix them for 5.1 surround if the tape supports Dlby digital/surround.
 

sq225917

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But the VHS (tape) signal is not digitized. The outputs are just for the onboard DVD player's SPDIF.

You'd use an outboard capture card/usb to get the VHS video+audio into a PC.


I'm talking about specific dvd recorders for making vhs tape transfers. Record the tape to dvd, then play it back to access the digi outs.
 

dorakeg

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I was looking to buy a few to test out. I know some folks here swear by Supra Cables being really solid quality. When looking into them they seem to guarantee 32 bit/384 kHz transfer (which I'm not even sure if Toslink is capable of outputting even that high out of most DACs) and claim to have the same performance as glass optical cables.

Ya, I am not sure if there are any devices that supports 32/284 input/output. If I am not wrong, most are limited to 24/96 or 24/192.
 
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