Making USB cables

[sbelyo]

I want to experiment with making some data only USB cables.  Looking at the specs of the bulk USB cable by lcomm it shows 28awg twisted for the data lines.  Is it ok to use stranded?

[Whitigir]

I don't see why not.  USB cables is just another cables.  The more complicated one would be the compatibility between 2.0 and type C.  Data only USB cables has no differences, what are your experimentations about ?

[MLA]

Assuming what you want to do is find out if cutting the computer power line reduces noise, it's just like bomb dismantling in the movies

Get two identical USB-cables that meet USB 2.0 standards (assuming audio is focus). Make a small incision in one of them with a sharp knife and cut the red wire. Voila, you now have two identical USB cables exept one does not carry computer power. A/B test away....

[sbelyo]

19 minutes ago, Whitigir said:

I don't see why not.  USB cables is just another cables.  The more complicated one would be the compatibility between 2.0 and type C.  Data only USB cables has no differences, what are your experimentations about ?

I want to see if cutting the power from the PC reduces the noise

6 minutes ago, MLA said:

Assuming what you want to do is find out if cutting the computer power line reduces noise, it's just like bomb dismantling in the movies

Get two identical USB-cables that meet USB 2.0 standards (assuming audio is focus). Make a small incision in one of them with a sharp knife and cut the red wire. Voila, you now have two identical USB cables exept one does not carry computer power. A/B test away....

Indeed, that's what I'm after.  Specifically I want to see if cutting the PC power and replacing it with a better supply will lower the noise coming from the dragonfly.  I intend to get one of those ifi isolator/re-clocker boxes but before dropping the $200 I wanted see see if I could do something with what I had laying around in regards to the power side of it.

[MLA]

The DragonFly? You may be in for some device generated problems that may or may not have to do with the power supply:

http://archimago.blogspot.se/2017/06/measurements-audioquest-dragonfly-black.html

Rather than dropping 200 on an isolator, you might want to try a different device first:

http://archimago.blogspot.se/2017/05/measurements-smsl-idea-usb-dac.html

That said, some quick cable surgery will probably give you the answers you need right away.

Edited July 19, 2017 by MLA

[Whitigir]

Yepe, just splice it and modify it.  Your question easily answered.

[sbelyo]

That's a cool looking little device.  I shall read through that.  I knew the dragonfly was noisy.  I only paid $50 bucks for it and was looking to use it only for travel.  It works fine for me in a pinch but of course I feel like tinkering with it a bit.

1 minute ago, Whitigir said:

Yepe, just splice it and modify it.  Your question easily answered.

gonna get some $1.00 cables from monoprice and see what happens

[sbelyo]

Hmm...  I'm also wondering if I have to or if it's possible to isolate the ground.  I must connect D+ D- and GND to the PC for the device to be recognized.

[sbelyo]

I picked up one of these for $23 on ebay

http://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-ADUM4160.html#eb-overview

[sbelyo]

That isolation eval board is pretty cool.  It cured the noise I was hearing when using the dragonfly with my tube gear.  

I'll eventually be making some cables to see if there's any difference.  Does anyone have a good source for A and B connectors and hoods?

I found these at mouser, but they don't have hoods

https://www.mouser.com/Search/ProductDetail.aspx?R=KUSBX-BP-KIT-SCvirtualkey51700000virtualkey806-KUSBX-BP-KITSC

https://www.mouser.com/Search/ProductDetail.aspx?R=KUSBX-AP-KIT-SCvirtualkey51700000virtualkey806-KUSBX-AP-KITSC