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USB Galvanic Isolation - Is that really necessary? - Page 3

post #31 of 66
9/26/10 at 10:12pm

If a device requires Hi-Speed USB to function, you can't possibly fault it for not being backwards compatible to USB 1.1. Granted, M2Tech should specify the exact USB requirements, but you can't fault them for what probably simply isn't possible if the default data rate really is at the Hi-Speed connection speed.

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post #32 of 66
9/26/10 at 10:25pm

Just like paying for an internet service of 6mb/s downstream, yet most of the time its less than that.

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post #33 of 66
9/26/10 at 11:22pm

Not exactly, if a chip runs at a specific data rate then unless it's designed to run at a slower speed it just simply won't run. Depending on implementation, it's not exactly as easy as dumping every few bits to reduce the data rate to what you need.

 

It's more like buying a game that requires a 2gb ram to run, trying to run it on a computer that only has 1gb and then claiming it should be able to run on only 1gb since it should be backwards compatible.
 

Quote:
Originally Posted by wuwhere View Post

Just like paying for an internet service of 6mb/s downstream, yet most of the time its less than that.

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post #34 of 66
9/27/10 at 7:21am
Thread Starter 

Interesting Nebby. What is your rationale of using the ADUM with your Gamma2? Are you experiencing some ground loop issue with your PC?

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post #35 of 66
9/27/10 at 7:58am

Basically, I figured it was a simple and cheap DIY build, with plausible benefits so I built it :) No ground loop issues but I like the idea of isolating the DAC from the computer.

 

Quote:
Originally Posted by K3cT View Post

Interesting Nebby. What is your rationale of using the ADUM with your Gamma2? Are you experiencing some ground loop issue with your PC?

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post #36 of 66
9/27/10 at 9:53am

Same here, I have a USB DAC cable that I would like to isolate from my PC/laptop.
 

Quote:
Originally Posted by Nebby View Post

Basically, I figured it was a simple and cheap DIY build, with plausible benefits so I built it " class="bbcode_smiley" height="" src="http://files.head-fi.org/images/smilies//smily_headphones1.gif" title=":)" width="" /> No ground loop issues but I like the idea of isolating the DAC from the computer.

 


 
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post #37 of 66
12/21/10 at 10:56am
Thread Starter 

Thread resurrect! tongue.gif

 

So does anyone still use these isolators nowadays? 

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post #38 of 66
12/21/10 at 4:20pm

nope.

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post #39 of 66
4/29/11 at 6:35am


I'm confused, you just linked to another thread with more usb isolators...

Quote:
Originally Posted by leeperry View Post

nope.



 

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post #40 of 66
5/19/11 at 2:58pm

Well I think he meant he really likes them. I would figure most of these ADuM4160 based isolator designs are more less the same, save for the difference between those that come with a separate power source and others that are entirely USB powered.

 

leeperry, not sure if you would see this, but here it goes anyway. Does it matter the Aimagin's dongle lacks external power source? I have been told for audio use an external power source is desirable; is that just for the cases when the power draw is more than the device can handle? Really, I don't really know enough on the subject, just taking a shot in a dark is all I am doing :) Are you aware of any similar designs that ADuM5000 as well? Thanks for the link, I will read up on it when I can.

Quote:
Originally Posted by Enthusia View Post


I'm confused, you just linked to another thread with more usb isolators...



 



 


Edited by MikoLayer - 5/19/11 at 8:48pm
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post #41 of 66
5/22/11 at 5:44am
ADuM5000 is good for up to 100mA as the specs page for the Aimagin's dongle suggests. (of the possible 400mA per USB spec, but um, not likely a small sound card will use that.)
Unfortunately, I've been having a problem with my one using it on my MD11.
a) When the dongle is connected, there is periodic crackling and short sample drops that don't occur when using the device without the isolator.
b) The max the dongle can do is 24b/48khz, while normally the same DAC can do 96k/24b and 192k/24b. (pit I don't have a normal isochronous type DAC to check it with, maybe it's something with musiland again)


Plus they ship it without a case, which is a bit disappointing for $69 (bit of a rip-off rip-off, for $10-15 worth of components)...(at least they should make it an option for people who aren't going to put it in their own box. )


> I would figure most of these ADuM4160 based isolator designs are more less the same, save for the difference between those that come with a separate power source and others that are entirely USB powered.

there aren't many parts on them, and it's probably a ref design from AD biggrin.gif ?... Aside from that there's the Aimagin one using 5k and 4160, but as I said above, I'm not really a fan right now.
Edited by svyr - 5/22/11 at 5:50am
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post #42 of 66
5/22/11 at 12:04pm

the olimex one is $37.75 + some reasonable amount of shipping (under $5 in my case) from MicroController Pros. The C@H one is $33 + $2 shipping including a PSU and all if you do the soldering on your own. Oleg said he would update the design to include the linear PSU in the link.

 

That sounds a whole lot better huh? :) 

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post #43 of 66
5/22/11 at 5:50pm
Quote:
Originally Posted by MikoLayer View Post

the olimex one is $37.75 + some reasonable amount of shipping (under $5 in my case) from MicroController Pros. The C@H one is $33 + $2 shipping including a PSU and all if you do the soldering on your own. Oleg said he would update the design to include the linear PSU in the link.

 

That sounds a whole lot better huh? :) 


Yea, they well might be better. (esp a linear PSU biggrin.gif )

About ref designs, it seems like analog publishes quite a few of them http://www.analog.com/en/circuits-from-the-lab/CN0159/vc.html, they also make eval boards even including the ADu5000 chip. http://www.analog.com/en/interface/digital-isolators/eval-adum4160/products/product.html . http://www.analog.com/en/interface/digital-isolators/adum4160/products/overview/over_CFTL_USB_Circuits/resources/fca.html (look at the eval board, Aimagin's board is probably heavily based on it, the switches and position of the two ADu chips, the jumpers...Except the slot for ADu5000 is empty on the eval board and the Aimagin board doesn't have the ext power terminal (it might be you either have the 5000 chip or ext DC))

$69 is a rip-off biggrin.gif - no case, no R&D, just a board ...

I hope Oleg ends up making some with cases and an option of either a PSU, or a ADu5000 chip (although it does seem pretty moot if you get a linear PSU + the isolator and hopefully in one box biggrin.gif , but the ADu5000 seems nice for portable setups)
Edited by svyr - 5/22/11 at 6:11pm
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post #44 of 66
5/30/11 at 1:14am
Quote:
Originally Posted by svyr View Post

ADuM5000 is good for up to 100mA as the specs page for the Aimagin's dongle suggests. (of the possible 400mA per USB spec, but um, not likely a small sound card will use that.)
Unfortunately, I've been having a problem with my one using it on my MD11.
a) When the dongle is connected, there is periodic crackling and short sample drops that don't occur when using the device without the isolator.
b) The max the dongle can do is 24b/48khz, while normally the same DAC can do 96k/24b and 192k/24b. (pit I don't have a normal isochronous type DAC to check it with, maybe it's something with musiland again)


Plus they ship it without a case, which is a bit disappointing for $69 (bit of a rip-off rip-off, for $10-15 worth of components)...(at least they should make it an option for people who aren't going to put it in their own box. )


> I would figure most of these ADuM4160 based isolator designs are more less the same, save for the difference between those that come with a separate power source and others that are entirely USB powered.

there aren't many parts on them, and it's probably a ref design from AD biggrin.gif ?... Aside from that there's the Aimagin one using 5k and 4160, but as I said above, I'm not really a fan right now.

wow, they have exceptional customer service though... Helped me try to debug the problem and sent a replacement unit with DHL as well. Friggin amazing.

EDIT: unfortunately the replacement is also experiencing crackling with Musilol MD11. Looks like it's incompatible.
Edited by svyr - 5/30/11 at 5:04am
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post #45 of 66
11/16/11 at 2:37am

Isolation based on Analog Devices ADUM3160:

 

 - Low cost and well proven for harsh environments

 - 2.5K isolation

 - A small number of components needed to build isolated device (see the picture below)

 

See our low cost galvanically isolated USB bridge on our blog page:

http://www.blog.kslemb.com/doku.php/en/blog/2011/1103ft2232d_usb_bridge

 

 

usb_com.jpg

 

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