Jud Posted June 30, 2019 Share Posted June 30, 2019 On 6/28/2019 at 5:01 PM, Chopin75 said: The copper wire is to convert optical back to electrical. It is not used for data transfer nor giving vBus. and yes it can cause noise contamination. I use your USPCB vbus off to block any leakage though not sure if it matters. I am merely talking regards to isolation with the optical part. Now is it truly galvanically isolated, not sure. If you reconsider the above, you may see that it isn’t correct. Continuity from one end of a connector to another is unnecessary to run optical-electrical converters at either end. That is why such converters can be used as isolators, because continuity isn’t necessary. If there is continuity, there isn’t isolation. A careful reading of the material on Corning’s web site shows the wires are there to provide the specified 5v USB power. So no galvanic isolation exists. No one can argue with your preference for the cable, but galvanic isolation isn’t the reason. In general regarding power sources, folks will want to think of not only what is in the direct signal path, but what is in the “power path.” What’s being kicked back into the power from the wall or whatever other source through power cabling or other connections in the ground paths of the equipment? Chopin75 and thotdoc 1 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Popular Post Jud Posted June 30, 2019 Popular Post Share Posted June 30, 2019 1 hour ago, davide256 said: Power supplies don't have a sound per se... but their imperfections excite problems in downstream equipment weaknesses. Not disagreeing at all. Just wanted to say that since electricity works in circuits, folks ought to try to think beyond the concept of “downstream.” Noise or other distortions flow where electrical laws dictate, not solely from power supply to signal source to amplification to speakers. thotdoc and jabbr 1 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted June 30, 2019 Share Posted June 30, 2019 11 minutes ago, Ralf11 said: Nice, but not a panacea. Considerations include noise associated with opto-electrical conversion, and whatever noise is kicked back into the mains by the units doing the conversion at each end. johndoe21ro 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted July 1, 2019 Share Posted July 1, 2019 10 hours ago, sandyk said: Hi Jud One advantage is, that although the power leads are in close proximity to the optical fibre, they can't induce SMPS noise from the PC/Server's +5V supply into the data pair like with a normal USB cable. This isn't a problem of course with the better USB cables where they sometimes fully separate the power and data lines. Kind Regards Alex Yep, the OP said the same, and I realize that. Owned one, but for me anyway it proved quite fragile. It stopped working pretty quickly, so I returned it. motberg 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Popular Post Jud Posted July 5, 2019 Popular Post Share Posted July 5, 2019 7 hours ago, 80levan said: Nice discovery. Sounds like the Corning and USPCB combo is a portable bus-powered opticalrendu. And with less reclocking and less ICs to further corrupt the signal. Reclocking doesn’t “corrupt.” It may reduce noise by giving the DAC input circuitry an easier signal to deal with, though that hasn’t been proved. Chopin75, sandyk and johndoe21ro 2 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Popular Post Jud Posted July 6, 2019 Popular Post Share Posted July 6, 2019 13 hours ago, Chopin75 said: Simplicity is the key for me. Now with additional devices, we are introducing potential dirty current into the chain, and more variables are added. External devices may have pros but the con of bringing additional jitter, RF/EMR etc all can degrade SQ. I presume you have already used good LPS for these devices, but results are still inferior? Regarding simplicity, that can be but isn’t always the way to get best sound. Two things are generally true in the usual computer audio setup: (1) Power from a normal desktop or laptop will not be terribly clean. (2) Clocking from the source can’t physically be as precise as clocking at the DAC. The second of these means that all else being equal, we’d want async USB input for the DAC. The first means we probably don’t want the desktop or laptop electrically connected to the same system as the DAC. A streaming device with clean power and good clocking seems to fill both requirements. It may also have the advantage of requiring a smaller capacity and thus less costly power supply. johndoe21ro and gstew 2 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted July 6, 2019 Share Posted July 6, 2019 26 minutes ago, sandyk said: Hi Jud Even with coax SPDIF you can get fabulous results from a DAC using a combination of a TCXO and a decoder chip such as the older DIR9001 which also uses a PLL along with the high quality OPTIONAL reference oscillator. Several minutes after switching on from cold you can hear the SQ jump up a notch in quality and stay there. That was particularly obvious with high res material, where the stability of the clocking appears to need to be far more precise for best results. Regards Alex SPDIF DACs have sounded just fine for a very long time. I'm simply pointing to the physical fact that when we are talking about picoseconds or even femtoseconds, the local clock must always be more precise than control from any remote location, *all else being equal*. This doesn't mean you can't have damn fine remote clocking, or bad local clocking. Chopin75 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted July 6, 2019 Share Posted July 6, 2019 4 minutes ago, Chopin75 said: Do u mean the local clock ie the clock in DAC? And remote clock is the music streamer or server or CD player etc... ? I do mean the local clock in the DAC. For async USB input, there may be some timing benefit to reclocking ahead of the input, depending on what John Swenson finds in his investigations and if those findings can be repeated. And there may be some noise benefit as I mentioned earlier due to the input circuitry in the DAC itself not being as subject to self-noise - again, a hypothesis awaiting proof. But both of these effects, if present, would depend on the streamer providing improved clocking and lower noise compared to what else would be in the system in its place (e.g., a laptop or desktop). (As you can see from my sig if not using the mobile view, I have - and very much like - a microRendu and ISORegen, so when I say there hasn't been proof of their efficacy, that is aside from my subjective thinking that they do something to the sound, and it's an improvement.) One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted July 7, 2019 Share Posted July 7, 2019 1 hour ago, Jud said: I do mean the local clock in the DAC. For async USB input, there may be some timing benefit to reclocking ahead of the input, depending on what John Swenson finds in his investigations and if those findings can be repeated. And there may be some noise benefit as I mentioned earlier due to the input circuitry in the DAC itself not being as subject to self-noise - again, a hypothesis awaiting proof. But both of these effects, if present, would depend on the streamer providing improved clocking and lower noise compared to what else would be in the system in its place (e.g., a laptop or desktop). One addendum to clarify: By "remote clock" I mean only a remote clock to which the DAC clock is slaved by PLL or otherwise, such as (but not limited to) SPDIF clocking. I don't mean reclocking the bitstream which then remains under ultimate control of the clock in the DAC, since the physical process that makes a remote master clock less precise (the time it takes to exchange signals between DAC and master clock) doesn't exist there. One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted July 7, 2019 Share Posted July 7, 2019 1 minute ago, Chopin75 said: Now with async USB input does it mean that the DAC is not forcing the clock upstream to clock with it and neither is the upstream clock being the master clock? So the audio signal coming into the DAC from the source would be reclocked in the DAC (usually at the USB-->I2S bridge) , correct ? Yes, reclocked in the DAC. One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Jud Posted July 7, 2019 Share Posted July 7, 2019 14 hours ago, Nenon said: However, when you not only pass signal from one stage to another but also do software processing, clean power and clocking are not the only things that matter. And this I believe is where we'd disagree. As it turns out more powerful processors are much better than slow processors. To me that means that processing latency is crucial, I don't understand how you get to latency being crucial when describing a streaming system where buffers tens of millions or billions of clock periods are being used. Can you describe for me what you are thinking here? Ralf11 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
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