I just acquired a Benchmark DAC2 and so far, I really like it.
This DAC use USB 2.0 connector (orange receptacle) and need a special driver to work under windows.
I use DIY cable on my system and everything is 99.9% or 99.999% silver from IEC cable to RCA, speakers and USB.
The dac refuse to work with my DIY USB cable.
My DIY usb cable work on my other 2 usb dac and also work fine on my external usb hard drive.
But when I plug it in the Benchmark, Windows doesn't recognise the device and refuse to work.
My cable has 5 distinct wires inside (all 23 or 24AWG 99.9% silver in Teflon sleeve, all straight run, and no twisted pair inside)
1-for the Gnd
1- for D+
1- for D-
1- for Vcc
And 1 for the metallic connector. This one is usually a separate, isolated shield on generic USB cable (or it connect to the pin 4 at one end?)
I also wonder if my 5th wire, usually shield on cheaper USB cable should have a resistor to prevent ground loop with pin4
I used the 5th wire to ground both body on the USB cable with an independent wire. (I understand that normaly, that would be an aluminium shield with a bit of resistance but my wire does the job.
My problem is possibly because of USB 2.0 on the DAC2.
My DIY cable work on everything but the Benchmark (Everything being USB 1.0 of course)
Maybe, should I use a small ferrite at both end of the cable like we often see on cheap ones?
Before anybody ask, the benchmark work fine with the factory provided usb cable...
Thanks for your input.
This DAC use USB 2.0 connector (orange receptacle) and need a special driver to work under windows.
I use DIY cable on my system and everything is 99.9% or 99.999% silver from IEC cable to RCA, speakers and USB.
The dac refuse to work with my DIY USB cable.
My DIY usb cable work on my other 2 usb dac and also work fine on my external usb hard drive.
But when I plug it in the Benchmark, Windows doesn't recognise the device and refuse to work.
My cable has 5 distinct wires inside (all 23 or 24AWG 99.9% silver in Teflon sleeve, all straight run, and no twisted pair inside)
1-for the Gnd
1- for D+
1- for D-
1- for Vcc
And 1 for the metallic connector. This one is usually a separate, isolated shield on generic USB cable (or it connect to the pin 4 at one end?)
I also wonder if my 5th wire, usually shield on cheaper USB cable should have a resistor to prevent ground loop with pin4
I used the 5th wire to ground both body on the USB cable with an independent wire. (I understand that normaly, that would be an aluminium shield with a bit of resistance but my wire does the job.
My problem is possibly because of USB 2.0 on the DAC2.
My DIY cable work on everything but the Benchmark (Everything being USB 1.0 of course)
Maybe, should I use a small ferrite at both end of the cable like we often see on cheap ones?
Before anybody ask, the benchmark work fine with the factory provided usb cable...
Thanks for your input.
shiny wire is no substitute for correct construction … your cable as it is, is an EMI noise source and not at all suitable for hi-speed data. its testament to the ruggedness of the USB 1.0 standard that it worked on the other devices
USB2 needs impedance matched ~90Ω (differential impedance ie. not resistance) twisted pairs
as for shield, it should be an actual shield (the wire is without utility) and it should be connected at both ends. no need for a resistor. if there is a direct ground loop between the chassis ground and USB ground in your dac or computer, somebody screwed up.
USB2 needs impedance matched ~90Ω (differential impedance ie. not resistance) twisted pairs
as for shield, it should be an actual shield (the wire is without utility) and it should be connected at both ends. no need for a resistor. if there is a direct ground loop between the chassis ground and USB ground in your dac or computer, somebody screwed up.
An interesting blog on USB cables:
MEASUREMENTS: USB Cables for Audio DACs.
Archimago's Musings: MEASUREMENTS: USB Cables for Audio DACs. [2013-06-18 UPDATE]
MEASUREMENTS: USB Cables for Audio DACs.
Archimago's Musings: MEASUREMENTS: USB Cables for Audio DACs. [2013-06-18 UPDATE]
Buy a cable, it will be better quality than you can make and will be designed for the job.
And using silver for a digital cable is a waste of money, you will get NO benefits from the silver.
As USB is LVDS you need twisted pairs for the differential signals or you are going to bugger them up.
And using silver for a digital cable is a waste of money, you will get NO benefits from the silver.
As USB is LVDS you need twisted pairs for the differential signals or you are going to bugger them up.
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