The true experimental tweak thread

[mansr]

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 USB-ISOLATOR: USB galvanic isolation

 

[ATTACH]32696[/ATTACH]

 

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?

 

The symbol on the case suggests it uses a transformer.

[Cornan]

The symbol on the case suggests it uses a transformer.

Yes, I agree.

 

Here is a drawing from their site that clearly shows the data isolation

 

 

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[Cornan]

The thing for me personally is that I already use unshielded USB cables without 5v and a GND lift. I would prefer a kind of isolation transformer for the data only that does not require additional power supply.

 

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[Cornan]

Thinking about it. I wonder if not a RCA type ground isolator like this one would be interesting to try?

 

 

But the question is if it would actually work connected to USB data?

I'll guess it is directional? ?

 

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[mansr]

The thing for me personally is that I already use unshielded USB cables without 5v and a GND lift. I would prefer a kind of isolation transformer for the data only that does not require additional power supply.

 

You could try an Ethernet transformer. It might not be quite so simple though. USB uses NRZI coding which might not work well over a transformer link without extra circuitry to restore the correct transitions, though that would need to be powered somehow.

[mansr]

Thinking about it. I wonder if not a RCA type ground isolator like this one would be interesting to try?

 

[ATTACH]32698[/ATTACH]

 

But the question is if it would actually work connected to USB data?

I'll guess it is directional?

 

For USB you'd need a transformer with a frequency range of about 100 MHz - 1 GHz. That audio transformer won't cut it.

[Cornan]

You could try an Ethernet transformer. It might not be quite so simple though. USB uses NRZI coding which might not work well over a transformer link without extra circuitry to restore the correct transitions, though that would need to be powered somehow.

Thanks mansr! I will look into Ethernet transformers. If it is possible to power with battery it could be an interesting experiment for both USB and/or copper Ethernet.

 

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[mansr]

Thanks mansr! I will look into Ethernet transformers. If it is possible to power with battery it could be an interesting experiment for both USB and/or copper Ethernet.

 

The transformer is already part of Ethernet, usually built into the RJ45 jack.

[Cornan]

The transformer is already part of Ethernet, usually built into the RJ45 jack.

OK, so that leaves my with USB and/or SAT. I have started to investigate Ethernet transformers. Any idea of a really good one?

 

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[Cornan]

@mansr

I just found this device when searching for Ethernet transformers

 

http://www.hjelmslund.dk

 

 

Do you know if this USB485-STIXL :*Isolated USB to RS485 converter could be used for my purpose?

 

http:// http://www.hjelmslund.dk/GET/PDF-STISOXL.asp

 

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[Middy]

how are you finding this stuff????

And thanks Mansr. Btw

 

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[Cornan]

how are you finding this stuff????

And thanks Mansr. Btw

 

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By pure chance! ? After reading about it it seems that it requires drivers to work though. I have e-mailed this company and asked if it can be used for my purposes.

 

I have also found this ADuM4160 chip which is a proper USB isolator chip http://www.mouser.se/m_new/Analog-Devices/adi-adum4160-usb-isolator/...but that is a bit boring for my tweaky brain! ?

 

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[mansr]

I have also found this ADuM4160 chip which is a proper USB isolator chip http://www.mouser.se/m_new/Analog-Devices/adi-adum4160-usb-isolator/...but that is a bit boring for my tweaky brain! ?

 

That chip doesn't support USB2.0 high speed required by DACs.

[Cornan]

That chip doesn't support USB2.0 high speed required by DACs.

Thanks, but this one do https://www.silanna.com/usb

I want to find a simple solution for the data+ and data- only. I will keep on searching for interesting & suitable solutions. It might take some time though since I'll need to understand it as well. Not there yet!

 

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[YashN]

how are you finding this stuff???

 

ADUMs have been discussed in these forums for years.

[Cornan]

ADUMs have been discussed in these forums for years.

Middy was referring to the USB to RS485 converter which I found by chance. Still do not know if it will work for my purposes.

 

I am trying to learn regarding USB isolator chips right now to understand how to make a USB data isolator only.

If you have information on which chip to use or any other means to isolate the USB data only please do share your knowledge so I can start searching in the right direction! ?

 

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[Cornan]

If I cannot find anything simple and useful for data isolation I think I will order the USBISO-AA to give it a try http://www.hjelmslund.dk

 

 

It works at high speed.

 

Since I am just after the data isolation this might be a valuable option for EUR60 +VAT & freight.

 

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[Liam]

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

 

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[ATTACH]32660[/ATTACH]

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[ATTACH]32662[/ATTACH]

 

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!

 

 

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Hi Cornan,

 

My router is connected by wireless to either my Mac Mini or iPad for streaming. In such case is there benefit to either, for example, to filter the router's own PSU with say a iFi DC iPurifier or by replacing it with a linear PSU? I suppose what I am asking is if the wireless data stream can be contaminated by a dirty router's DC supply?

[mansr]

Hi Cornan,

 

My router is connected by wireless to either my Mac Mini or iPad for streaming. In such case is there benefit to either, for example, to filter the router's own PSU with say a iFi DC iPurifier or by replacing it with a linear PSU? I suppose what I am asking is if the wireless data stream can be contaminated by a dirty router's DC supply?

 

No, electrical noise is not carried over wifi.

[Cornan]

Hi Cornan,

 

My router is connected by wireless to either my Mac Mini or iPad for streaming. In such case is there benefit to either, for example, to filter the router's own PSU with say a iFi DC iPurifier or by replacing it with a linear PSU? I suppose what I am asking is if the wireless data stream can be contaminated by a dirty router's DC supply?

 

Hi Liam,

 

My own purpose of getting a galvanicly isolated lab psu is to try to block the noises from the router to the ac mains and the backwash noises from the ac mains to the router. If you have a wireless or wired connection does´nt matter in this case since it pollutes your ac mains and affects all your ac connected devices. In my own setup I only have two ac connected devices. My DAC/HPA/PRE and my router. Remaining devices is powered by battery disconnected to ac mains (including uphill FMC). I want to make sure that both of these devices are galvanicly isolated.

 

I am still waiting for the 4mm banana plugs to DC 2.1/5.5mm plug cable to arrive and have´nt actually put the Voltcraft to the test. As soon as I have recieved it I will post my SQ impressions compared to the supplied SMPS.

 

The iFi DC purifier is possible to use in any case since this device is not dependant on which kind of DC PSU you are using. Personally, if I am happy with the SQ I will consider to add a ATL DC blocker pre the Voltcraft as well. I use one in-line version pre my Peaktech 2240 tech isolation transformer with great results.

[YashN]

If I cannot find anything simple and useful for data isolation I think I will order the USBISO-AA to give it a try USB to RS485 converter shop

It works at high speed.

 

Since I am just after the data isolation this might be a valuable option for EUR60 +VAT & freight.

 

This doesn't do high speed. You are confusing the actual USB speeds.

Some of the limited speed devices will not work for higher rate audio though.

[Liam]

No, electrical noise is not carried over wifi.

 

Thanks mansr. That's one less thing to be concerned about then.

[Cornan]

This doesn't do high speed. You are confusing the actual USB speeds.

Some of the limited speed devices will not work for higher rate audio though.

Removed. I did´nt read that properly. I guess it works but will reduce the speed from hi-speed to full-speed. I'll guess I will have to search for other solutions.

[mansr]

As far as I can see it is a full speed isolator that works with USB 2.0 (480mbit/s), but when at high speed it can only run at 480mbit/s (and not at slower speeds). See details here: http://www.hjelmslund.dk/Files/Product%20sheet%20-%20USBISO-AA.pdf

 

That says it will accept high-speed devices but reduces the speed to "full" nonetheless. Your DAC may not like this, and it certainly won't allow more than 96 kHz operation.

[Liam]

Hi Liam,

 

My own purpose of getting a galvanicly isolated lab psu is to try to block the noises from the router to the ac mains and the backwash noises from the ac mains to the router. If you have a wireless or wired connection does´nt matter in this case since it pollutes your ac mains and affects all your ac connected devices. In my own setup I only have two ac connected devices. My DAC/HPA/PRE and my router. Remaining devices is powered by battery disconnected to ac mains (including uphill FMC). I want to make sure that both of these devices are galvanicly isolated.

 

I am still waiting for the 4mm banana plugs to DC 2.1/5.5mm plug cable to arrive and have´nt actually put the Voltcraft to the test. As soon as I have recieved it I will post my SQ impressions compared to the supplied SMPS.

 

The iFi DC purifier is possible to use in any case since this device is not dependant on which kind of DC PSU you are using. Personally, if I am happy with the SQ I will consider to add a ATL DC blocker pre the Voltcraft as well. I use one in-line version pre my Peaktech 2240 tech isolation transformer with great results.

 

Thanks Cornan. I understand now it is contamination of the mains you are primarily concerned with.

 

Where do you place your meter probes to check for galvanic isolation please?