Jump to content

Rate this topic

Recommended Posts

I can start off this thread with one of my several coming experiments. I have quite a few coming. Some more crazy than the other. This one is a USB data enhancer which contains a USB A female plug>Vactrol VTL5C1 analogue linear optocoupler (opto-isolstor)>USB A male plug.

I want to test if USB data wires are sensitive to noises caused by over-voltage, DC currents and leakage loops. I am not expecting a big improvement initially...but are very curious to "turn that stone" to see what is hiding there.

 

I will post my experiences here when all the parts for it have arrived! :)

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
I can start off this thread with one of my several coming experiments. I have quite a few coming. Some more crazy than the other. This one is a USB data enhancer which contains a USB female plug>Vactrol VTL5C1 analogue linear optocoupler (opto-isolstor)>USB A male plug

 

How will you handle initial device detection?

Share this post


Link to post
Share on other sites
How will you handle initial device detection?

 

This is the "experimental" parts of this thread. No experiment is too crazy to try. A hunch is enough to get going. I have already ordered the parts and expect to get a result by a week or two. The worst case scenario is that it doesn't improve anything..but at least I have not left that stone unturned! ;)

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites

I recently built this 100Base-TX cable which is an improvement over Audioquest forest, Audioquest Cinnamon, Supra Cat 7+ and Supra Cat 8.

 

1484948455490.jpg

 

It contains 22awg silver plated wires with teflon sleeving connected to Deltaco tool-free RJ45 plugs and screw terminal RJ45 plugs. Connected to pin 1&2 plus 3&6 on a distance to reduce capacitive coupling.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
This is the "experimental" parts of this thread. No experiment is too crazy to try. A hunch is enough to get going. I have already ordered the parts and expect to get a result by a week or two. The worst case scenario is that it doesn't improve anything..but at least I have not left that stone unturned! ;)

 

I expect it to not work at all. USB device detection uses pullups on the data lines to indicate presence and supported speed. An optical isolator will prevent that. This is the same reason the ground wire needs to be connected for initial handshake.

 

To achieve full isolation you'd need some active circuitry on both sides exchanging side-channel signals to provide the achieve the correct responses to both sides. I guess the Intona device does something like this.

Share this post


Link to post
Share on other sites
I expect it to not work at all. USB device detection uses pullups on the data lines to indicate presence and supported speed. An optical isolator will prevent that. This is the same reason the ground wire needs to be connected for initial handshake.

 

To achieve full isolation you'd need some active circuitry on both sides exchanging side-channel signals to provide the achieve the correct responses to both sides. I guess the Intona device does something like this.

Thanks mansr!

I know very little about optocouplers. Instead of endless search for answers I have ordered the parts that make sense to me. In any case I will give it a try. But do I understand you correctly that these optocouplers might need a 2-leg dip switch to work?

I mean like USB GND needs a switch to be disconnected?

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
Thanks mansr!

I know very little about optocouplers. Instead of endless search for answers I have ordered the parts that make sense to me. In any case I will give it a try. But do I understand you correctly that these optocouplers might need a 2-leg dip switch to work?

 

Bypassing the optocoupler during the handshake might work.

Share this post


Link to post
Share on other sites
Bypassing the optocoupler during the handshake might work.

Thanks a million! That really made my day! :)

I will add a 2-leg dip switch to my order and report back asap.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Edited by Cornan

Share this post


Link to post
Share on other sites
Bypassing the optocoupler during the handshake might work.

Also recall that USB is bidirectional. Your optocoupler needs to transfer signals both ways.

Share this post


Link to post
Share on other sites
Also recall that USB is bidirectional. Your optocoupler needs to transfer signals both ways.

Not sure how that will change things in my experiment? My USB cables are data only after handshake...so no power and no GND. I will connect the Vactrol to the Data+ & Data- on both ends with a 2-leg dip switch which I will turn off when the GND handshake is performed. Not bidirectional?

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
Not sure how that will change things in my experiment? My USB cables are data only after handshake...so no power and no GND. I will connect the Vactrol to the Data+ & Data- on both ends with a 2-leg dip switch which I will turn off when the GND handshake is performed. Not bidirectional?

 

Can you explain in more detail, perhaps with a circuit diagram, how you intend to wire this up?

Share this post


Link to post
Share on other sites

I just got a delivery of a $70 linear lab PSU for my router

 

1484951134808.jpg

1484951146774.jpg

1484951146774.jpg

1484951159585.jpg

1484951163568.jpg

 

Added a Deox-it treated AHP gold fuse and measured the galvanic isolation with my multimeter set on continue-mode. No beep, no value & no nothing. I'll guess it is a winner! I am still waiting for my 4mm banana plug>2,1/5,5mm DC wire to arrive before I can evaluate it. In any case to these eyes it looks pretty amazing for the price! :)

 

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
Can you explain in more detail, perhaps with a circuit diagram, how you intend to wire this up?

I have no circuit diagram, but it is quite straight forward.

I will connect USB pin 2 & 3 to the VTL5C1s two channels at both ends with a 2-leg dip switch in-between.

It will essentially serve as a USB A female to male adaptor. I will actually make two since I have one USB cable from my Aries Mini to USB Regen and one from USB Regen to my DAC.

If it'll improve things I want to add them to my copper Ethernet and my twisted pair SAT cable as well...if I just can figure out how.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
I have no circuit diagram, but is is quite straight forward.

I will connect USB pin 2 & 3 to the VTL5C1s two channels at both ends with a 2-leg dip switch in-between.

 

Two channels? The VTL5C1 consists of an LED illuminating a photoresistor. It is decidedly unidirectional. Moreover, it has a response time measured in milliseconds. That's not enough even for low-speed USB. You need something with sub-nanosecond response time for USB2.

Share this post


Link to post
Share on other sites
Two channels? The VTL5C1 consists of an LED illuminating a photoresistor. It is decidedly unidirectional. Moreover, it has a response time measured in milliseconds. That's not enough even for low-speed USB. You need something with sub-nanosecond response time for USB2.

OK, any suggestions of a sub-nanosecond respons time optocoupler?

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
Sorry, can't help you there. What's in the Intona isolator?

My coming experiment are starting to look like a failure before it have even started. Just got word from John Swenson that even if you use two optocouplers and a switch it is not likely to succeed, probably due to lack of speed as you pointed out.

 

I do not own a Intona...but are you sure that Intona also isolate the data+ and data-?

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
AFAIK, it's FPGA-based, custom code/hardware description.

Not a off-the-shelf solution in other words. Anyway, this experiment do not seem to be possible to pull off as is. Needs serious re-thinking or a nice little throw into the trash can.

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites

Even I hoped that Otpo emulating chip I found would just work by soldering a few wires to the legs. But it takes electrical knowledge and a custom circuit just to get it working. The isolation in the intona being a small transformer between the 2 FPGA'S.

There is a cheaper version mentioned on here but I can't remember it's name.

I think there are bi directional Optos models but that IC PDF shows some average MEGS PS.

This a what if thread, so a thousand no's is still a valued learning experience.

 

 

 

Sent from my SM-G900F using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites
Even I hoped that Otpo emulating chip I found would just work by soldering a few wires to the legs. But it takes electrical knowledge and a custom circuit just to get it working. The isolation in the intona being a small transformer between the 2 FPGA'S.

There is a cheaper version mentioned on here but I can't remember it's name.

I think there are bi directional Optos models but that IC PDF shows some average MEGS PS.

This a what if thread, so a thousand no's is still a valued learning experience.

 

 

 

Sent from my SM-G900F using Computer Audiophile mobile app

 

That is the whole idea by creating this thread. To share experiments that you have inside your head. With some friendly advices everyone can gain knowledge by success and failure.

 

I have found this little CESYS USB isolator interesting http://www.cesys.com/products/usb-isolator/

 

1485001281471.jpg

 

https://m.conrad.se/Galvanisk-separering-%28GND-Lift%29-fr%e5n-v%e4rddator-och-USB-enhet-CESYS-C028149.htm?websale8=conrad-swe.01-aa-m&pi=1165503&ci=SHOP_AREA_17630_0406153

 

It isolates the data wires as well. Have you or anybody else heard of it?

 

 

 

 

 

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites

Personally I would have something else than a USB isolator. I do not want yet another device in the chain. I'll rather await the coming uber-Regen and cross my fingers it will have galvanic isolation of the data wires! 😊

 

Sent from my Nexus 7 using Computer Audiophile mobile app

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×