USB connect DIY


#1

Hi there
I just introduced a nice gear Mutec MC 3+ USB between my USB interconnect of iMac and Directstream. It’s an amazing device not only by its galvanic USB separation but also by a complete reclocking function and its perfectly inner clock synchronized with a Rubidium clock. But that’s not my issue. I think of a DIY USB cable and the idea is to use a cat6 cable with 4 twisted pairs of wires. Why this idea? the CAT6 cable should be safe in data transfer. It’s double shielded. I’ll use it only for audio streaming. So the 5V wire can be neglected. For the 2 data lines I’d like to take one wire from each twisted pair, ie. 4 wires for data + and 4 for data -.
How do you think of this idea? Any suggestions?


#2
djr said Hi there I just introduced a nice gear Mutec MC 3+ USB between my USB interconnect of iMac and Directstream. It's an amazing device not only by its galvanic USB separation but also by a complete reclocking function and its perfectly inner clock synchronized with a Rubidium clock. But that's not my issue. I think of a DIY USB cable and the idea is to use a cat6 cable with 4 twisted pairs of wires. Why this idea? the CAT6 cable should be safe in data transfer. It's double shielded. I'll use it only for audio streaming. So the 5V wire can be neglected. For the 2 data lines I'd like to take one wire from each twisted pair, ie. 4 wires for data + and 4 for data -. How do you think of this idea? Any suggestions?
You'll have problems if you don't follow the USB specs, especially the length (< 15') and the VBUS line which is needed to reliably tell whether a device or a hub is being added to a USB tree. Tying multiple conductors in parallel may both add too much capacitance and may add dispersion (i.e. jitter) if the lengths aren't matched pretty well. You can certainly try it and see if you like the difference.

#3

Hi Ted
thank’s for advice. I’ll try several modifications. The length won’t be a problem. Will be about 1,5 m. However in electronics I’m a newbie. So please apologize any silly question. I read that the 5V line should not be necessary in audio stream because there is no need to support any USB device with voltage. I’ll only use data +/- and mass. 5V should be off. To avoid capacitance I’ll combine only one line of a twisted pair with another of a second pair. Is it correct that the shield will reduce capacity. In total 3 lines for data + and - shield and one pair for mass.
best wishes Adolf


#4
djr said Hi Ted thank's for advice. I'll try several modifications. The length won't be a problem. Will be about 1,5 m. However in electronics I'm a newbie. So please apologize any silly question. I read that the 5V line should not be necessary in audio stream because there is no need to support any USB device with voltage. I'll only use data +/- and mass. 5V should be off. To avoid capacitance I'll combine only one line of a twisted pair with another of a second pair. Is it correct that the shield will reduce capacity. In total 3 lines for data + and - shield and one pair for mass. best wishes Adolf
When your cable doesn't work reliably hook up the VBUS (5V) line. I explained that it's needed and there are few systems that work with the DS without the VBUS connected - yours may be one now, but perhaps not, say, when you get a new release of your PC's OS, or new DS code, or add a hard drive to your USB...

#5

Ok, I got it. Thanks for advice.

Adolf


#6

Hi Ted
meanwhile I received my USB plugs from Asia. I tried a 1,5 CAT cable. I connected each pair of shielded lines (white/braun, white/blue, white/yellow and green/rose as single USB line. Works quite good and looks good. Especially acoustic instruments sound very realistic i.e piano, harp and drums (short and dynamic punch).

greetings Adolfdancing-009_gif


#7

Thanks for the update - enjoy your system.