Digital Cables

Introduction

I ventured into CD separates recently (and reluctantly) with the introduction of a parametric equaliser (Behringer DEQ2496) into my system in order to correct serious room modes in my listening room. Though the DEQ2496 has a built in DAC, it was about the same quality as a good budget CD player but not good enough for me. So I got a Northstar DAC too. In one shot, my digital cable requirement went from 0 to 2 (1 RCA, 1 AES/EBU)

Baseline

Initially, for RCA, I just used my existing Audioquest Video 2 (HFC recommended component) but continuous swapping between DVD player and CD player isn't practical in the long run. As for XLR, I just used my DIY soldered Belden 89207 (an early attempt at soldering. The joint is not pretty :) )

 

The Lineup:

Baseline

 

 

Testing Methodology etc

I had never compared digital cables before and I wasn't even sure that there was going to be a difference, so I borrowed the PSAudio and VdH first. The QED was acquired subsequently after discovering that digital cables did make a difference :)

Testing was done by A/B-ing the cables in various combinations using the usual CDs that I am very familiar with. The cables only had a few hours of run in. But as I write this, the cables I kept have gone through several more days of use.

The cables are connected in the following order:: CDP - (digital RCA) - DEQ2496 - (AES/EBU) - DAC.

 

The review

The PSAudio XStreams, whether RCA (vs the other RCAs) or XLR (vs the Belden) have the same sonic signature. The thing that immediately struck me was the solidity of the imaging. Voices and instruments became more fleshed out and clearly defined. Coupled with what appeared to be a clearer midrange, this made female vocals very much more attractive. At the top end, the XStream was smooth yet detailed and not rolled off. However, this was something that one has to get used to and initially I found it a bit too smooth for my taste with both XStreams in the chain even though all the existing detail was there. In addition, I felt that dynamics at certain points was improved, for example, close-miked plucking of guitars had more 'snap' to them. As for the bass, I felt it was pretty much the same. The PSAudios were clearly a different class from the other cables.

The VandenHul Digi-coupler I found was more or less the same standard as the Audioquest Video 2 (which is a pretty good cable, HFC recommended and all that) but with a different tonal presentation. It was smoother and darker than the AQ, more in line with the PSAudio. It had almost similarly solid midrange presentation and imaging but the highs seemed rolled off compared to the PSAudio which was smooth but yet retained treble detail.

The QED P75, despite being a budget cable copper only cable (the others are all silver plated copper I think), also acquitted itself well against the others (pity I can't say the same about the QED Subwoofer cable but thats another story...) It is very slightly lacking in detail and rolled off compared to the AQ and XStream but has a touch of midrange emphasis that is attractive in certain circumstances. Given the usual (stereotypical perhaps?) performance of HT systems with nasty highs (and metal dome tweeters) and lack of midrange intelligibility, the P75 could be a winner. The P75 and the XStream was an interesting contrast. Though there was a slight touch of midrange emphasis to the P75, this did not improve imaging. So the improvement of imaging with the XStream is something more than making the midrange louder and more intelligible.

One thing that I've omitted to talk about is this notion of 'blacker than black' backgrounds, the sound of silence etc. Personally, I think its a question of taste. Too silent, and the recording sounds dead, too noisy, the recording sounds hashy. My usual tests for this are the Mary Black CDs - the quieter songs where there are lots of pauses and also in the intros where there is a lot of 'energised' silence where you hear the sound of the room (or the poor s/n ratio of the reverb processor :) ). Though there were small differences, I really didn't think them to be that significant, though occasionally, the VdH would sound a bit too 'dead' in some places.

Conclusion

I couldn't afford both PSAudio cables so I got the AES/EBU XLR to replace my Belden. After running in further, I beginning to appreciate its merits even more. I also got a QED P75 which was intended for my HT but I'm running it in with my 2 channel system and it is a very nice performer indeed though ultimately, I think I'll put the AQ back.

I have very little idea why digital cables have sonic differences (lots of jitter related explanations on the internet though). On my 2 cable system, changing just 1 cable makes an clearly audible difference so on the standard 1 cable system, I expect the changes to be even greater.