Kimber Kable USB Cables [Archive] - Audio & Video Forums

dynaco_user

06-29-2014, 11:52 AM

I happened to come across this review of Kimber Kable USB cables

Kimber Kable Select USB cables - Top Audio Gear : Top Audio Gear (http://www.topaudiogear.com/index.php/kimber-select-usb-cables/).

After reading the text I am at complete loss as to why any USB cable would be far superior to another never mind how a USB cable can have any influence how music sounds as this reviewer indicates. I always thought USB cables carried digital information and had no bearing on how the D to A converter converted the digital information to analog. It seems to me that as long as the cable carries the digital information at the rate needed and maintains the proper signal levels, life is good. As long as the stream of 1s and 0s coming out of the cable matches what went in the cable, the cable did its job and it doesn’t matter if the cable is machine made or hand made, has copper or silver conductors, or whatever.

What science am I missing that would make the reviewer see enough difference in the audio between one USB cable and another to make one of those 1 meter cables worth $500 plus?

Feanor

06-29-2014, 12:30 PM

I happened to come across this review of Kimber Kable USB cables

Kimber Kable Select USB cables - Top Audio Gear : Top Audio Gear (http://www.topaudiogear.com/index.php/kimber-select-usb-cables/).

After reading the text I am at complete loss as to why any USB cable would be far superior to another never mind how a USB cable can have any influence how music sounds as this reviewer indicates. I always thought USB cables carried digital information and had no bearing on how the D to A converter converted the digital information to analog. It seems to me that as long as the cable carries the digital information at the rate needed and maintains the proper signal levels, life is good. As long as the stream of 1s and 0s coming out of the cable matches what went in the cable, the cable did its job and it doesn’t matter if the cable is machine made or hand made, has copper or silver conductors, or whatever.

What science am I missing that would make the reviewer see enough difference in the audio between one USB cable and another to make one of those 1 meter cables worth $500 plus?

The principal problem with any cable that carries digital information is that it might introduce jitter, i.e. timing errors. This can happen with any S/PDIF cable, coax or optical; it can also happen with USB cable, at least with synchronous transmission. However it seems to me to be far less of the problem in case of asynchronous transmission in which case the receiving device controls the timing (rather than the transmitting device).

I don't know about the Kimber cable, but I bought a Pangea USB with silver-plated wire because I had the maximum allowable USB run of 15 feet between my computer and DAC. I wondered if it would improve the sound in any way but it did not. My Schiit Audio DAC does have asynchronous USB so perhaps that had something to do with hearing no difference.

dynaco_user

06-29-2014, 04:23 PM

The principal problem with any cable that carries digital information is that it might introduce jitter, i.e. timing errors. This can happen with any S/PDIF cable, coax or optical; it can also happen with USB cable, at least with synchronous transmission. However it seems to me to be far less of the problem in case of asynchronous transmission in which case the receiving device controls the timing (rather than the transmitting device).

I don't know about the Kimber cable, but I bought a Pangea USB with silver-plated wire because I had the maximum allowable USB run of 15 feet between my computer and DAC. I wondered if it would improve the sound in any way but it did not. My Schiit Audio DAC does have asynchronous USB so perhaps that had something to do with hearing no difference.

I am not an EE so I might be way off base here but if were designing a circuit that used a DAC I think I would have at least one stage of FIFO buffering between the USB incoming data and the DAC so that the DAC received what it needed for every clock cycle from the buffer regardless of any jitter in the incoming data. I do not think I would depend on timing from an external source that is beyond my control for the timing needs of my circuit.

I am still left to wonder what real advantage such a cable would have on the analog output, particularly in light of your experience with your Pangea USB cable.

Sir Terrence the Terrible

06-30-2014, 07:10 PM

I am not an EE so I might be way off base here but if were designing a circuit that used a DAC I think I would have at least one stage of FIFO buffering between the USB incoming data and the DAC so that the DAC received what it needed for every clock cycle from the buffer regardless of any jitter in the incoming data. I do not think I would depend on timing from an external source that is beyond my control for the timing needs of my circuit.

I am still left to wonder what real advantage such a cable would have on the analog output, particularly in light of your experience with your Pangea USB cable.

If I were you, I would not spend much time worrying about jitter. The jury is still out on the audibility threshold of jitter, and not all jitter is the same. You can have jitter in the reproduction device, the software, and even the transmitting connectors like S/PDIF.

There is different jitter with different thresholds of detection. You have period jitter, absolute jitter/wander, peak-to-peak and RMS, wideband jitter, baseband jitter, and long-term jitter. Each of these has a different level of detection, and it is anyone's guess what that is.

The studies I have seen on jitter point to don't waste your time on the subject.