CD signal out vs transport interconnects. Why/which?

[krabapple]

Thanks guys, all.

If using the player only as transport to dac across very short distance (stacked on top of each other), toslink or coaxial?

Both are S/PDIF.
for your use case it MAKES NO DIFFERENCE.

 

[NTTY]

DVD players are more likely to change the digital output than a pure CD player, especially if they have an HDMI output.
The standard says that protected high-res data can only be output at max 16bits/48kHz on SPDIF. Some manufacturers don’t bother much and process all digital sources through an ASRC for SPDIF output, thus modifying the CDA digital stream even if that is theoretically unnecessary.

 

[roddo]

FWIW,
I ended up with a CD transport that outputs coax, optical and USB.
USB was the clear winner when conducting A\b testing. Cleaner with a more distinct sound stage,
then coax, which still sounded better then optical.

 

[NTTY]

FWIW,
I ended up with a CD transport that outputs coax, optical and USB.
USB was the clear winner when conducting A\b testing. Cleaner with a more distinct sound stage,
then coax, which still sounded better then optical.

This is very unlikely unless massive issue with some of the outputs.

 

[RandomEar]

FWIW,
I ended up with a CD transport that outputs coax, optical and USB.
USB was the clear winner when conducting A\b testing. Cleaner with a more distinct sound stage,
then coax, which still sounded better then optical.

Sound stage is a property of the recording with some interactions of speakers and room. No digital transport has any influence on it, because no digital transport changes the actual audio data in any way (unless defective).

Sighted listening comparisons with long switching times (>5 s) and no level matching are inherently flawed and will not give you trustworthy results under any circumstances.

 

[antcollinet]

This is very unlikely unless massive issue with some of the outputs.

And if there were - it wouldn't change sound stage or "cleanliness" one iota - problems would manifest as one or more of dropouts/clicks/ticks/pops.

 

[NTTY]

That’s what I meant by massive
From the test of the Fiio DM15, I was nothing else but impressed by the modifications of the digital signal. We’re getting closer to hearing threshold. Long time ago, the OPPO 105 had an issue, which I identified to come from digital processing, which showed itself only in some particular instances (+3dB in one channel and heavy clipping, that can be heard).

Now, a difference between coax and optical SPDIF output, probably not, unless significant ground issue / hum noise travelling via coax cable, maybe.

 

[roddo]

Or maybe my optical cable isn't the greatest.

Anyhow, soundstage: appeared clearer, ie the instruments were easier to place. Not wider or taller. The USB signal, in my case, just seemed to de-merge things.

Sorry if my response, and my ears, contradict your dogma.

 

[NTTY]

Or maybe my optical cable isn't the greatest.

Unlikely, unless you're using 100m+ cables, maybe, at least to generate a super massive amount of jitter.

Anyhow, soundstage: appeared clearer, ie the instruments were easier to place. Not wider or taller. The USB signal, in my case, just seemed to de-merge things.

Again, unless significant digital signal processing is happening between these, then no.

Sorry if my response, and my ears, contradict your dogma.

Dogma? Seriously?

 

[RandomEar]

Or maybe my optical cable isn't the greatest.

Anyhow, soundstage: appeared clearer, ie the instruments were easier to place. Not wider or taller. The USB signal, in my case, just seemed to de-merge things.

Sorry if my response, and my ears, contradict your dogma.

Science is not a dogma. Testing things incorrectly and without sufficient controls leads to wrong conclusions. That's not surprising at all. Typical mistakes (as already explained above):

• Not knowing or disregarding bias (by testing sighted)
• Not level matching
• Now knowing about or disregarding the effects of the very short nature of echoic memory

In your case, the additional problem is that you either don't know about or ignore the properties of digital signals: Apart from bit errors, jitter and noise on the ground plane there's nothing that could alter the sound in any way. Noise would be immediately audible when the device is turned on and nothing is playing and I have never seen a case of actually audible levels of jitter (which doesn't lead to the receiving device loosing the connection). If there were any other errors like bit flips, you would immediately hear those as louds pops, clicks and other blatantly obvious problems. If you ever used an old portable CD player without a buffer or you altered individual samples in an audio editor, you will know how absolutely not subtle those errors are.

Since you did not mention any noise, drop-outs or pops, the only plausible assumption is that the data passed through all interconnects in the same bit-perfect form and there was no audible difference between them whatsoever. Insisting that this is wrong while ignoring all the logic behind this argument would be... dogmatic.

 

[antcollinet]

Or maybe my optical cable isn't the greatest.

Anyhow, soundstage: appeared clearer, ie the instruments were easier to place. Not wider or taller. The USB signal, in my case, just seemed to de-merge things.

Sorry if my response, and my ears, contradict your dogma.

(My bold)

They don't. You haven't tested blind and level matched, so your ears have contradicted nothing, in fact they have confirmed that uncontrolled listening results erroneous conclusions.

If you had tested blind and adequately controlled, and therefore were able to prove there were a difference to be heard, we would then be in the game of finding out which of the connections was faulty in some way - still contradicting nothing. But it certainly wouldn't be differences in the sound stage you were hearing. Errors in the digital signal can't do that. Basic engineering dictates it as pointed out above.

The USB signal, in my case, just seemed to de-merge things.

Or are you able to come up with a well grounded science or engineering based argument as to how that could happen.

 

[Sokel]

To some extend, dead cheapo optical cables PLUS sockets (at the gear side) with these horrible plastic ends are not the exact definition of quality and are highly susceptible of all kinds of faults.
Tested, proper ones though are just fine.

Edit: having a look around, Benchmark ones seems really nice at first glance.

TOSLINK Optical Cable with Metal Connectors for Digital Audio

Benchmark-Approved TOSLINK Optical Cables - We have selected these cables based upon their performance and durability. These exceptional optical cables feature precision metal ends that provide the strength and rigidity required to maintain accurate optical alignment with TOSLINK transmitters...

benchmarkmedia.com

 

[Roland68]

To some extend, dead cheapo optical cables PLUS sockets (at the gear side) with these horrible plastic ends are not the exact definition of quality and are highly susceptible of all kinds of faults.
Tested, proper ones though are just fine.

Edit: having a look around, Benchmark ones seems really nice at first glance.

TOSLINK Optical Cable with Metal Connectors for Digital Audio

Benchmark-Approved TOSLINK Optical Cables - We have selected these cables based upon their performance and durability. These exceptional optical cables feature precision metal ends that provide the strength and rigidity required to maintain accurate optical alignment with TOSLINK transmitters...

benchmarkmedia.com

If the fiber optic cable were made with genuine quartz glass optical fibers, then the price would be reasonable, but they don't mention that, and it wouldn't be possible with that bending radius.

With standard POF fiber optic material, it's the same nonsense as with some expensive HiFi cables and outrageously overpriced.
Good quality POF fiber optic cable costs about €2-4 per meter from a retailer.

Metal connectors are absolute rubbish and counterproductive. The connectors should be made of black, matte plastic. A glossy finish is counterproductive because it can cause reflections, and metal connectors will eventually damage the sockets because the mating is designed for plastic. I know a technician in a repair shop who could tell you a thing or two about that. Even Toshiba issued a notice for their original Japanese Tosling connectors and sockets stating that they shouldn't be used with metal connectors.

Good quality, pre-assembled fiber optic cables from a brand cost around €5-10 per meter. I would advise against using no-name fiber optic cables, as there is now a lot of inferior POF fiber optic material on the market.

If you want truly high quality, order pre-assembled cables by the meter from a fiber optic cable supplier. With the best material, this costs around €12 per meter, and with quartz glass, around €25-40.

Incidentally, the Toslink cables, which are only 2.2 mm thick and more rigid, are the better option.

 

[krabapple]

FWIW,
I ended up with a CD transport that outputs coax, optical and USB.
USB was the clear winner when conducting A\b testing. Cleaner with a more distinct sound stage,
then coax, which still sounded better then optical.

Nonsense.

 

[roddo]

Nonsense.

Which part? That I found USB a cleaner sound? I don't recall you being in the room.

Seems some ppl do not understand subjectivity, and I again refer to my earlier comment on dogma.

 

[Ropeburn]

Which part? That I found USB a cleaner sound? I don't recall you being in the room.

Seems some ppl do not understand subjectivity, and I again refer to my earlier comment on dogma.

On the contrary, we understand subjectivity all too well. Which is why strong scepticism is to be expected.

 

[Roland68]

Which part? That I found USB a cleaner sound? I don't recall you being in the room.

Seems some ppl do not understand subjectivity, and I again refer to my earlier comment on dogma.

Which CD drive and which DAC did you end up using?

 

[krabapple]

Which part? That I found USB a cleaner sound? I don't recall you being in the room.

Seems some ppl do not understand subjectivity, and I again refer to my earlier comment on dogma.

I understand it well. Do you understand how dubious your report based on it is?

Have you even, for a moment, being a reader and contributor to Audio Science Review, considered an alternative explanation is for what you 'heard'?