13. Digital cables

13. Digital cables

6/4/2020

Author: Karsten Hein

Category: High Fidelity

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There are no absolutes in life, and knowledge is by far the biggest hindrance to continued learning. Because only if we challenge established beliefs can we be sure that they still hold true in our time. After all, the Bahamas were discovered in a period, when Europeans had decided that the earth was flat. Exploration needs a playful mindset that favours personal enterprise to established fear. The rewards can be quite bountiful, indeed.

When I set out to purchase a digital cable, I wanted to make sure that the signal coming from the CD Player was conveyed to the DAC in as pure a fashion as possible. I ordered a high quality fibre optics Toslink connector, as well as one four-times shielded cable of RCA/cinch coaxial standard for comparison. Prior to listening, I was convinced that the light pulse connection of the Toslink would present the purest result. To my surprise, this was not the case. Instead, the music sounded rather two-dimensional and flat, sticking to the speakers rather than being presented in the room. In the combination of Denon DCD 1420 and Cambridge DAC Magic, I found the Toslink connection to be less appealing to my ears than running the signal via the CD player’s own internal DAC. I did some research and found that this was a common phenomenon, possibly due to the quality of the two electro-optical converters involved.

In contrast, the RCA/cinch coaxial connection sounded better than the internal DAC, right from the start, even with the volume adjusted to a lower level. The music was immediately more engaging. However, in longer listening sessions I noticed some unpleasantness in the highs and some issues with the phantom center which comes from mono signals in the recording and should be fairly wide in scope. Although digital signals are claimed to be free from interference, because of the way they are transmitted, the sonic signature of the issue was familiar to me from HF distortion, e.g. to be found on power cables. I consequently started experimenting with ferrite clamps. First, I attached one clamp and moved its position along the cable, looking for sonic changes. Although I had some better and some worse results, none was actually pleasing. I then brought in a second ferrite, and, placing them both on opposite ends, finally had the sonic coherence that I had previously been missing.

The picture below shows a four-times shielded cable of RCA/cinch coaxial standard that I confectioned with a Viablue cable sleeve and two ferrite clamps. The cable sleeve has not been attached for optical reasons. I found that larger ferrite clamps have a better effect on sound, but with their growing outer diameter, the inner diameter also became larger. The cable sleeve has helped me to bridge this gap. Considering the amount of building material in use, the fully confectioned cable is still very affordable, especially in comparison with ready-made solutions.