Interesting / Informative post by John Siau of Benchmark Audio

Absolute_Zero
Absolute_Zero Posts: 72
edited February 2016 in 2 Channel Audio
This is a post of his from Real-HDaudio.com. I came upon this while researching USB cables. I just wanted to know I had a quality cable and bumped into this controversy. I picked up a Belken Gold USB cable from Amazon. Nice cable for $8.

*note I think he mistyped 1000 and it should be 100

This is John Siau, VP and Director of Engineering at Benchmark Media Systems, Inc.

I can confirm that we do not recommend purchasing high-priced USB, AES, or Optical cables to achieve an improvement in the sound.

When we introduced the DAC1 in 2002 we published detailed FFT plots that compared the performance of the DAC1 connected with two different cables: Cable 1 was a high-quality 2-foot long balanced AES cable and Cable 2 was 1000 feet of CAT 5e cable. Both produced the same results at the output of the DAC1 because the DAC1 has near-perfect jitter attenuation (see page 36 of the DAC1 manual). This plot confirms that the sound did not change when 1000 feet of generic CAT 5e wire replaced the short high-quality AES cable.

However, I should point out that the 1000 foot cable really put the DAC1 jitter attenuation system to the test. This is demonstrated by the eye-pattern plot on page 29 of the same manual. This plot shows that the 100 foot cable caused significant attenuation and distortion of the waveform that was carrying the digital information. In spite of this distortion, the DAC1 was able to recover all of the bits and was able to fully attenuate the clock jitter that was induced by the long low-quality cable. see http://benchmarkmedia.com/pages/manuals

Bottom line – A fancy digital cable may improve the shape of the waveform that carries the digital data, but if the DAC is well-designed the cable will not change the analog waveform exiting the DAC. On the other hand, if the DAC is not well-designed, a long, low-quality digital cable may cause changes at the analog outputs.