Why does SPDIF basically suck?

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On 2018-05-11 at 11:26 PM, sandyk said:

Well implemented Coax SPDIF can sound markedly better than most USB implementations , although it's bandwidth is inadequate for recent DSD implementations, where there is a limited amount of material available, and not in popular music either.

There is no reason why Coax SPDIF's bandwidth couldn't be markedly improved these days if there was a will to do so.

 

I agree a well implemented coax can sound better than most USB. To say that SPDIF suck sucks 

 

Chord use two coax cables with BNC connectors between BLU2 and DAVE (up to 705.6kHz, 768kHz). DCS Vivaldi can play 384kS/s and DoP/64, DoP/128 with dual AES.

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On 2018-05-13 at 3:43 AM, Superdad said:

Standards are a good thing, but the S/PDIF standard--originally not even meant to be used externally--really ought to just fade away in the computer audio arena.

 

And still you use I2S (which was not made to be used externally), so it’s possible (I guess) to improve the design like has been done with LVDS I2S.

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14 minutes ago, Ralf11 said:

another question is how much damage do unnecessary conversions really do in the digital domain - under what circumstances will jitter increase to hearable levels, for example?

 

Conversions between different forms of digital codex has its advantage. One type of design and protocol can be better at reducing RF noise or can be used to send over long distance, another is better at reducing jitter and so on. No digital protocol sucks only the implementation.

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19 hours ago, Audiophile Neuroscience said:

Depends what you mean by "most USB". Comparing apples with apples, for me, well implemented USB sounds better than well implemented coax spdif or aes/ebu or glass ST fibre (the bayonet connection)

 

I mean all the DACs I have own have sounded better with I2S or coax. All of the DACs I have been able to test with different digital inputs have sounded better or equal to USB.

 

Comparing apples with apples can be made with Music Players like Aurander W20/N10, Auralic Aries etc. You can also compare if the sound gets better or worse by using something like a mR/uR direct to DAC or with a good DDC with BNC/SPDIF/AES (apples to orange).

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20 hours ago, Superdad said:

 

Well I2S internally--right from the Ethernet or USB input board--with master clocking done right.

I2S (via LVDS over HDMI) is rarely done in ideal fashion as the source ends up as the master clock (very few DACs feed master clock out to slave the I2S source).

 

I personally presently use I2S external (modified Singxer SU-1 feeding I2S/DSD over LVDS/HDMI cable to Holo Spring L3) because the Crystek CCHD-575 clocks in the Singxer are a lot better than the clocks in the Spring (and/or the USB input of the SU-1 is better).

 

There is nothing preventing an enterprising manufacturer/designer from developing a more ideal--and yet still operating system "sound card driver" compatible--two piece solution with....  (oops.    shhh... ).

 

I don’t know how your reply are related to my respond to your declaration that SPDIF wasn’t even meant to be used externally when in fact it was I2s and that haven’t stopped you from using it, and shouldn’t.

 

I wonder which digital codex, commonly used today, that wasn’t originally meant to be used for audio? 

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17 minutes ago, miguelito said:

Kids: Just use an external clock like dCS does!

 

 

And look which type of cable they are using to the external clock 

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8 minutes ago, miguelito said:

BNC... Why?

 

They use a coax cable with BNC connectors. SPDIF use the same 75 Ohm coax cable and this is a thread about “Why does SPDIF basically suck”.  

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6 minutes ago, mansr said:

He already said he misspoke, misremembered, or mis-something-else.

 

Yes, but it was his intention to put something down sole because it was “originally not even meant to be used externally”.

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8 minutes ago, mansr said:

If S/PDIF sucks, it's not because of the cable or connector.

 

SPDIF doesn’t suck!

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1 hour ago, Superdad said:

 

I certainly never said it did.  I don't see the world in back-and-white. 

 

My original point was simply that, unless one is producing a really good, well clocked S/PDIF single right in the source computer (eschewing USB altogether), the choice to use S/PDIF is just a choice to do USB>I2S>S/PDIF conversion externally--and to then require another S/PDIF>I2S conversion in the DAC.

 

Between elimination of stages and the ability to slave an internal USB>I2S board to the DAC master clock, there would seem to be very few decent arguments in favor of using an external DDC.  The only valid argument I have ever heard was that the DAC designer's USB (or Ethernet) input did not have enough effort put into it.

 

Cheers,

--AJC

 

I don’t believe conversions between different digital interfaces is bad, I even think it has its advantage; like one type of transmission and protocol can be better at reducing RF noise or can be used to send over longer distance, another type of protocol can be better at reducing jitter and so on.

 

I actually think most would go USB >S/PDIF or Network >USB >S/PDIF (which includes conversion, buffering and reclocking) externally and when S/PDIF>I2S conversion in the DAC. What will be lost or add in the conversion VS Network > USB > USB externally and USB > I2S conversion in the DAC?

 

Okay the only valid argument for me is if the sound improves with a DDC, USB regen, render or not. I have tested with some DACs and mR/uR or JCAT USB direct to DAC didn’t sound as good as mR/uR or JCAT USB to DDC BNC/SPDIF to DAC.  

 

No wired digital interface sucks, only some implementation. The same is true for tube vs SS; R2R vs SD, render vs server; planar vs dipole vs horn vs box speakers; Class A vs class A/B vs class D.

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5 hours ago, miguelito said:

You mean the same cables and connectors used in lab equipment to get very clean multi-gigahertz signals around? The same connector used in just about all scopes, even the fastest ones?

 

The BNC connector is very hard to improve on. 

 

If you want use coax cables and connectors normally used in lab equipment it will work well. If it’s also the ultimate best for sound is another story I don’t wish to debate.  

 

The BNC connector is very good, but some like the 110 Ω AES/EBU even better. 

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17 hours ago, Audiophile Neuroscience said:

 

 

Fair enough! My experience is the opposite with respect to coax vs usb. I guess that's why they say YMMV

 

 

Okay am curious, which DACs and Music players that have both coax and USB have you used?

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7 hours ago, Marcin_gps said:

 

All DDCs I've tried add coloration - it can be good or bad depending on the system and a DDC, but it's one more component in the chain plus an extra cable. It always alters the sound. 

If one has a clean USB output from a PC (or streamer) and a USB input board in a DAC is done right (a separate PSU, decent clock etc), I don't see a reason to use a DDC. In my system any DDC affects performance negatively. 

 

I see that you totally dismiss my experience and my theory regarding conversions between different digital interfaces. But okay let’s say that you are correct and I like some added coloration. If that’s true it must also be the reason I have a JCAT LAN, don’t you think? I mean my preference for some extra coloration is probably constant. 

 

Don’t worry you are not alone in your thought about the degradation caused by conversions between different digital interfaces or the deprivation made by adding more component in the digital transmission chain. I can only report what I hear and it’s not in line with your or most others in this thread. But it’s not all. Not only do I use a JCAT LAN and a DDC. Those are connected to my ultraRendu, which besides being a RoonReady output converts Ethernet to USB which is a sort of Digital to Digital Converter (DDC) .

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8 minutes ago, Panelhead said:

  I have a Light Harmonic Infinity. It has AES, Coax, and USB inputs. The hard part was finding a source with both coax and AES outputs. 

  But with my cheap system and tin ears the order was AES, coax, and USB. I no longer use the Infinity. But if I did I have a coax now made with 12G 4K UHF cable. Maybe it is better than the Canare, Gotham, and Sommer RG6 used in the first evaluation. 

 

I have a 12G 4K UHF cable and its okay, but I clearly prefer my AQ Eagle Eye. I have put 8 ferrets on it and it has enhance the sound more than I thought possible.

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18 minutes ago, look&listen said:

Surprised still passes signal after ferrets done chewing!

 

Yes it’s so strange and still so typical of high fidelity – What we may think must be the best design or approach is not always so IRL.

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9 hours ago, Audiophile Neuroscience said:

 

Some years back I started to wonder about changing to computer usb over transport/spdif when I was getting sound quality from a laptop into an RME Babyface DAC that rivaled my Reference Mark Levinson 31.5 > aes/ebu (or coax spdif or AT&T ST fibre) >30.6. I listened extensively to many combos & dacs at various dealers, too many to list, some of which i also auditioned at home including MSB Platinum stack and a UMT transport, tried and purchased Bricasti Mi Dac and then Gryphon Kalliope.

 

Is it really too much to ask for that the ones that claim SQ superiority (or call things crap) of one design over another also state which audio gear the result was made. General statements that DDC or S/PDIF etc are inferior is very hard to take serious if no reference to which gear that been used are made.

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8 hours ago, miguelito said:

That’s a balanced connection, a different beast. We are talking clocking here. BNC is perfect for that.

 

No no you are mistaken we are debating S/PDIF in this thread which is a digital interface for carrying digital audio signals between devices over either optical or electrical cable. S/PDIF is not made or used to send a pure clock signals between external reference clock and DACs. The clock aspects discussed here is very different from the one that is sent from a reference clocks, the frequency is also different. The only thing they have in common is the cable and connectors. It’s just like with LVDS I2S, which is a totally different digital interface than the HDMI that is used to stream movies. The only thing in common is that they often can use the same HDMI cable for carrying digital audio signals between two devices.

Okay back to basic. S/PDIF is a digital interface developed by Sony and Philips. S/PDIF is a protocol as well as a set of physical layer specifications for carrying digital audio signals between devices over either optical or electrical cable. S/PDIF was developed at the same time as the main AES3 standard, that are used to interconnect professional audio equipment in the professional audio field. S/PDIF is almost identical to AES3 (AES/EBU) at the protocol level and differ in that it has different connectors. With one exception the S/PDIF protocol is identical to AES3. The difference is that channel status bit differs in S/PDIF.

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1 hour ago, Marcin_gps said:

 

It's not the same. Replacing a component with sth better always leads to better sound. Adding a component that is not required in the chain - not necessairly. 

 

And saying that ultraRendu converts Ethernet to USB is a huge oversimplification... ultraRendu is a micro PC. 

 

What I was trying to say is that in computer audio there is no need to engage S/PDIF at all unless we have some really old school DAC like Audio Note which lacks USB connectivity.

 

 

 

Charming, and if I or someone else get better SQ result by adding an Offramp 5, Singxer SU-1, Berkeley Alpha USB, or are using the coax from something like an Aurender, Auralic Aries, are we only fooling ourselves or have tin ears?

The crapping on S/PDIF and DDCs here is IMO so low, the tech explanations given for the added coloration so vague and real apples to apples comparisons with named gear almost none existing to motivate me to continue this discussing.

BTW, manufactures that says that all but their design is crap and are calling their costumers fools for using what they think sound best will not be supported by me.

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3 hours ago, miguelito said:

Ok read my answers... I said that the issues with clocking would be solved if you also added a word clock connection like dCS has. Those connections work on BNC connectors. 

 

I was not talking about the SPDIF signal itself, which likely would better transmit over a balanced connection than a single-ended one.

 

What issues with clocking are you talking about and with which specific audio gear have this problem occurred?

 

How does a word clock connection like DCS  change how the S/PDIF clock sync work?

 

If the problem with clocking would be true for S/PDIF. Which it’s not! Why would it be better to transmit over a balanced connection rather than a single-ended one? Please do tell?

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4 hours ago, Audiophile Neuroscience said:

 

I do not claim anything apart from telling you what I heard on what gear.As I said YMMV.

 

You can favor whatever digital interface you want. All am asking for is for you and everyone else that says that S/PDIF is inferior or crap to tell me with which audio gear you made this apple to apple comparison. It’s good practice that one declare the reference if ask for.   

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22 hours ago, mansr said:

Only if it is transformer coupled or optical. Many implementations are not.

 

What do you mean? All good DDCs have some form of transformer coupling to isolate from the (often noisy) USB source. The $179 Schiit EITR for example has it, so it’s not only implemented in very expansive DDCs. The GI is and has always been one of the pros of a DDC or external renderers.

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15 minutes ago, mansr said:

Maybe all the good ones do. I was also talking about S/PDIF sources in general, not just USB interfaces.

 

To use the S/PDIF or any other digital interface direct out of a standard computer is never good for SQ and IMO no good example when we are discussing pros and cons of different types of digital interface, on a site named Computer Audiophile.

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29 minutes ago, miguelito said:

Completely agree on the diffs between design and implementation, and btw the vagueness of "this sounds better", especially comparing single ended vs balanced spdif.

 

Yes, the dCS clocks ain't cheap! I know first hand...  But even with a great clocked system, all in sync, if you feed it with an SPDIF source from a source that is not on that clock network you're back to square one. So there...

 

I wonder who is comparing the vagueness of "this sounds better", single ended vs balanced S/PDIF??

 

 

Ohhh it’s you!!

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6 minutes ago, mansr said:

What about the iFi Nano?

 

It’s not easy to implant GI in a portable battery-powered device. It’s one of the limitations of battery-power and is well known.

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5 minutes ago, mansr said:

Whatever your excuses, it's an "audiophile" USB to S/PDIF bridge without a transformer.

 

Is it? Okay use it then I don’t care. It probably go well with the rest of your "hifi" gear.