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USB 3.Optical


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Thanks. This looks very neat for long connections and should prevent any electrical-noise contamination.

 

I don't know how such a cable performs in term of jitter though. I would be inclined to reserve its use for long connections to DACs that have very good re-clocking abilities.

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I don't know how such a cable performs in term of jitter though. I would be inclined to reserve its use for long connections to DACs that have very good re-clocking abilities.

 

As long as you use asynchronous USB transfer, it doesn't matter because clock is at the DAC side and doesn't depend on the USB transfer... So nothing to reclock, because there's only one clock - DAC's.

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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Yes, of course as long as there is any galvanic connection, there's no optical isolation. Only when the connection is purely optical it is isolated from problems like ground currents or PSU noise leakage.

 

So far, optical ethernet has been nice way to provide a true isolation and long distances.

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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Hi Miska,

 

Would you be good enough to provide a source for optical ethernet hardware?

 

Thanks,

 

Joel

 

I did some googling around and I also could not find. Is there a possibility to "adapt" the fiber with the same RJ45 endings (sorry, probably sounds stupid for the knowledgeable).

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Would you be good enough to provide a source for optical ethernet hardware?

 

I'm using HP 1810-24G switch that has SFP optical interface option.

 

Then there are SFP+ interfaces for server adapters, like:

Intel® Ethernet SFP+ Optics Product Brief

 

You can find bunch of fiber gigabit adapters, like:

Server Adapters | Allied Telesis

 

And then there are just media converters, like:

MC1000 Series Media Converters | Allied Telesis

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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I could place my order through this page,

USB Optical Cables by Corning

 

My friend in U.S. told me that a power supply mechanism for a "bus-power" in the device seemed to be based on a DC-DC converter.

I think I will be able to discard the power supply and use my local power supply instead.

 

They told me a possible delivery was expected at the middle or end of June.

 

Documents available at Corning web site say the cable can be used only with self-powered external USB devices. I interpreted this description meant that a complete galvanic isolation between a computer and peripheral USB 3.0 devices might be obtained though they said nothing about such an isolation.

 

However, the next question hit me.

How do the complicated opto and electronic chips built in the USB connector at the external USB side get necessary power through the optical cable?

 

Hi, Miska! Do you have any idea regarding this point?

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Let's remember that optical transmission has costs as well as advantages. Galvanic isolation is great, but what noise penalty is generated to gain it? Light doesn't carry charge but does have timing and amplitude noise which every receiver must contend with. So let's get some noise measurements of the transmitted and converted signals before we jump up and down. For short distances like <10m I would expect electrical connections to perform better per dollar spent.

Mac Mini 2012 with 2.3 GHz i5 CPU and 16GB RAM running newest OS10.9x and Signalyst HQ Player software (occasionally JRMC), ethernet to Cisco SG100-08 GigE switch, ethernet to SOtM SMS100 Miniserver in audio room, sending via short 1/2 meter AQ Cinnamon USB to Oppo 105D, feeding balanced outputs to 2x Bel Canto S300 amps which vertically biamp ATC SCM20SL speakers, 2x Velodyne DD12+ subs. Each side is mounted vertically on 3-tiered Sound Anchor ADJ2 stands: ATC (top), amp (middle), sub (bottom), Mogami, Koala, Nordost, Mosaic cables, split at the preamp outputs with splitters. All transducers are thoroughly and lovingly time aligned for the listening position.

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There are electrical connections through these "optical" cables if you read closely.

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 to EtherREGEN -> microRendu -> ISO Regen -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

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Hi, Jud!

 

Thank you very much for your comment. My concern is at the point.

Woul you tell me which descriptions you read closely led you to the conclusion?

 

Bunpei

 

Hi Bunpei. Sorry I don't recall the specifics as it was quite some time ago, several months at least, that I and others discussed this on the Phasure forum. You could try searching there, or perhaps you may find what we did if you look into detailed information like specifications on Corning's site.

 

I do recall there was no doubt in anyone's mind by the time the discussion was done that these cables had full length electrical connections and did not provide galvanic isolation.

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 to EtherREGEN -> microRendu -> ISO Regen -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

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