DIY USB Cable (separated power and data)

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I would like to make some DIY USB cables that separate the power from the data so that I can add power.
eg;
Code:
RPi   USB---data only-------------USB   DAC
                                  |
Power USB-------------------------|

Can someone recommend UK source for cable and connectors? Cable should be 90 ohms I think?

Something like the iFi Gemini Dual-Headed USB Cable but not costing USD200!!
 

Made one of these quickly and easily over the weekend, just to try it out. Worked just fine.

Got me wondering about two further options based on this:
1) Can I make my own "data" cable - its just a USB-A at one end and a pair of wires? I can then solder to a new USB-B plug, along with a re-used USB-A for the power. My thinking was the quality of the power lead doesn't matter, but the quality of the data lead is important?
-or-
2) Could I make a small box with USB-A sockets and just do simple internal wiring inside the box, and then use standard USB cables in and out?
eg;
Code:
USB-A===data====|box|===USB-B===DAC
USB-A==power====|   |
The advantage of the "box" would that all of the cables are completely standard ?
 
Made one of these quickly and easily over the weekend, just to try it out. Worked just fine.

Got me wondering about two further options based on this:
1) Can I make my own "data" cable - its just a USB-A at one end and a pair of wires? I can then solder to a new USB-B plug, along with a re-used USB-A for the power. My thinking was the quality of the power lead doesn't matter, but the quality of the data lead is important?
-or-
2) Could I make a small box with USB-A sockets and just do simple internal wiring inside the box, and then use standard USB cables in and out?
eg;
Code:
USB-A===data====|box|===USB-B===DAC
USB-A==power====|   |
The advantage of the "box" would that all of the cables are completely standard ?
For the power cable the red/active cable is disconnected but the black/ground cable is left connected along with the data lines. This is to allow the "handshake" to occour between the data sending device and the dac/receiver . Without the handshake the data would not be recognised.

I expect this would be the same for a custom data cable. you would need 3 wires... 2 data plus the ground.

I see no reason why you couldn't make a custom cable for data as per the TNT one but using your choice of cable but I also see no benefit either.

Improvements are more likely to be seen with better quality power cabling and supply. Most of the commercial usb cables power lines are more suited to trickle charging mobile phones than supplying the current needs of a dac...
Google "Raspberry Pi lightning bolt" for discussions around these issues....
 
Last edited:
Disabled Account
Joined 2019
Greetings,


Those are surely better than the Ifi and cheaper :


PANGEA PREMIER XL Cable USB-A Male/USB-B Male 2.0 Gold plated Cardas Copper 0.5m - Audiophonics


A simple Lindy USB A to B should be enough thoug. Just disconect the external screen on the receiver (B) side (which is sharing the ground with the internal black wire) to have a real screen and not a pick up antena. Cut the red/black wires at the emiter side (A) 2" above without totally cut the external screen and put there an Allo wall wart.


USB 2.0 Printer Cable,2 Packs 2.0 Printer Scanner Cable Cord USB Type A Male to B Male High Speed for HP, Canon, Lexmark, Epson, Dell, Xerox, Samsung etc(0.5M/1.5Ft): Amazon.co.uk: Electronics



Of course if your receiver is already 5V bus powered, just cut the red wire at the A side. Please notice some dacs needs sensing, so make test before with cheap USB wires then take a better one with braided screen and transparent silicon insulation (same price but less sensible to moves).


Up to 96/24, this litting thingy might help : HiFimeDIY USB Isolator
 
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