In Reply to: Synergistic Research USB Cable posted by Mercman on February 17, 2008 at 09:42:27:
Gang,
Look there are 2 cables inside a USB cable. There is the DATA differential pair that must be designed for traffic up to at least 12Mhz and the POWER cable which is VBUS 5V's and Ground.
I have like tons of cables now and some do sound different. But remember it will be device dependent.
All of the PCM27xx devices require VBUS to determine the computer is there. This means there is current running from the computer to the USB Device via the POWER side of the cable.
Other devices like the TAS1020 look for signal on the DATA portion of the cable only. Therefore the VBUS is not used and only the Ground connection on the POWER side is used.
On the DATA side termination on the Device side or endpoint will have an effect on transmissions. I usually get the 5M cables put them on a couple of computers with my USB analyzer on the DAC side and check for errors.
It's not suggested to use a 5M with streaming audio. These cables were meant for low speed devices. 2M and under for audio will make all the difference in the world.
With the POWER side being used it can bleed noise from the computer into the dac.
It would be nice if you could switch the VBUS signal on the computer side from VBUS to Ground if your device doesn't use it.
Anyways another thing about the POWER side of the cable is that noise from the computer can end up on the device. The cable should do all it can to make sure that doesn't happen.
It's best like all aspects of this hobby to try this stuff before you buy it.
Remember using these expensive cables on a hard drive is worthless they are in Block mode not Streaming and will not be effected by the use of costly cables.
Thanks
Gordon
J. Gordon Rankin
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Follow Ups
- Guys remember what the cable does and why they make a difference - Gordon Rankin 08:37:08 02/18/08 (9)
- This may have already been asked somewhere, BUUUT.... - TopPop 19:09:05 02/18/08 (1)
- RE: This may have already been asked somewhere, BUUUT.... - leica_man@hotmail.com 05:48:46 02/19/08 (0)
- RE: Guys remember what the cable does and why they make a difference - Adal 16:03:57 02/18/08 (0)
- RE: Guys remember what the cable does and why they make a difference - Adal 16:01:58 02/18/08 (4)
- A little insight - Gordon Rankin 09:54:57 02/19/08 (0)
- RE: Guys remember what the cable does and why they make a difference - audioengr 18:10:18 02/18/08 (2)
- RE: Guys remember what the cable does and why they make a difference - Adal 06:59:13 02/19/08 (0)
- In bursts? - Slider 22:00:48 02/18/08 (0)
- RE: Guys remember what the cable does and why they make a difference - audioengr 12:48:35 02/18/08 (0)