I have been called a fool many times. In the seventies, when I was among the first to write about differences in speaker cables, and later when I discovered the same kind of sound changes with interconnects. In the nineties power cables became an issue. Now that streaming audio has usurped my CDs the time has come to “listen” to Ethernet cables. Ethernet cables! Yes, indeed, they do alter the sound of a system. Audioquest was kind enough the supply me with several lengths of Pearl and Cinnamon CAT-7 cable, my own network served as a test facility.
The cables
Audioquest Pearl and Cinnamon are CAT-7 Ethernet cables, that is cables that can transport data up to speeds of 10 Gigabits per second. A big advantage of CAT-7 is the connector, it’s a much more rigid type than a plastic RJ-45 (piece of junk), it is also a shielded cable, but the shielding can be overall and/or for each individual pair of wires. Audioquest pays special attention to the 23 AWG (gauge) solid conductors, the high-density polyethylene isolation material and the shielding. Pearl is the simpler of the two with solid core copper conductors, Cinnamon adds 1.25% of silver to the copper and has better shielding under the PVC sleeve. Audioquest claims these cables are directional and an arrow on the connecter indicates the data flow from source to receiver.
Network
My home network is set up with the router, NAS (network attached hard drive) and Vortexbox media player in a closet in the hall. These are connected to a Linksys Gigabit switch with Supra CAT-7+ cables, the router uses a cable that came out of the box. From this central switch I run standard CAT-5 Ethernet cables to two other switches, one in my living room, one in the study. In the study a small Linksys switch is connected to the study switch just for convenience but it’s normally not in use. The connections to my music players are Supra CAT-7+ too, one metre to a NAD M50 and eight metres to my Naim UnitiQute. Supra is my reference but not for any special reason, it was just the first one I came across. I find it neutral and far better than ordinary Ethernet cables.
It’s a pity my NAS doesn’t support auto crossover on the second Ethernet port, you always need a switch or a crossover cable for direct connection from NAS to streamer. Maybe Audioquest could introduce crossover cables since it might me the best option to connect a media player directly to a NAS, however you need a second LAN interface on the NAS (my Synology has one). However a good switch is very useful since it will suppress jitter on the network, eliminate errors, re-clock and boost the signal. You don’t need a professional, noisy, managed Cisco or other expensive brand. Linksys and many others have excellent switches for home use in the range of 40 to 50 Euros for 8 ports.
Listening
I rolled out 12 metres of Pearl cable from my central switch directly to the Naim. Changing to one switch while running Pearl is a noticeable step back compared to the Supra runs and multiple switches. But it’s preferable by far to standard cable solutions. The sound with the Pearl becomes lighter and has less impact and detail compared to the Supra. Stereo image shrinks, but more obvious is a reduction in detail. Changing to Cinnamon with only one switch in my network produces a surprising result. One Million Bicycles from Katie Melua’s CD Live At The O2 Arena opens up and suddenly the public plays a much more important role at the beginning and end of the song. The people where always there but with the Cinnamon they not only come alive, they are also more spaced out and more like individuals. After changing back to a two switch network with standard cable between the switches (and Supra to my Naim), Cinnamon stays the winner with the one switch run. What is apparent is that at least the cable between the device and the last switch does count, but what about the cable between the switches? In the two switch run the standard piece of cable in between might be the bad guy. It’s quite easy to test, I just have to run a Cinnamon cable through the hallway between central and study switches, instead of the nicely hidden standard one. Doing so gives me back a more detailed sound that’s very easy on the ear with better instrument detail. Like the organ that comes to the foreground, the whistle is now tonally richer and Katie’s voice is more exciting. Small recording errors that appear, for instance when Katie gets too close to the mic, add to the live experience.
This file is a 16/44.1 FLAC file ripped from a CD, it should be very easy to transport on a Gigabit network. One step higher is a studio master from Cæcily Norby at 24/96. Which means that over three times more data has to be transported. I ran Cinnamon between the two switches and swapped the link between my switch and the Naim from Cinnamon to Supra. The Supra sounds darker and adds weight to the low end, but not in a tight way, it enhances low frequencies and they sound muddy. Running the same sort of tests again as I did with the Melua recoding I get comparable results. Best results are either Cinnamon cable all over or at least Cinnamon between your last switch and the streaming device. The difference between one switch and two switches can be ignored with Cinnamon from beginning to end. If you need to save some money you can combine Pearl and Cinnamon, run the better cable to your streamer and the cheaper one from switch to switch.
I used long lengths, 8 to 12 metre cables for the above, and was curious to find out what short lengths might do. A little 5-port switch stands beside my Naim. It’s connected with cheap Ethernet cable to the room switch and again to the central switch. Three switches in a row and four cables to compare: standard, Supra, Pearl and Cinnamon. Music used was a 24/96 WAV file of Paper Airplane by Alison Krauss & Union Station. Changing from standard wire to Pearl introduces more space, less strain and easier flow. The sound opens up like a flower to the sun. The next cable, Supra, is more refined and puts some extra detail in the strings of the guitar. There seems to be no way back to standard Ethernet cable. Cinnamon is the more airy cable, but has less detail than Supra. In this short run Supra is my favourite but Cinnamon comes very close. To be honest I wonder if I could say which cable is being used if they weren’t compared side by side. Supra is a little more forgiving, Cinnamon is the harder sounding cable, more eager.
Knowing the above results I moved to my main system in the living room to start a re-indexing of my music on the NAD M50 streamer (I disconnected the M52 Music Vault and started playing music from my NAS instead). The M50 is connected over standard Ethernet between the central switch and the local switch, much like the Naim set-up in the study. In the past I have changed from standard cable to Supra with excellent results, but when the M52 came in Ethernet was only used for remote control and internet access. Music files being locally stored and fed to the M50 via USB. I swapped Supra, Pearl and Cinnamon again using an old favorite, The Eagles’ Hotel California (24/192). Moving from Supra to Pearl creates a loss of stereo image, a lighter sound and not the presentation I was used too. A side step to standard cable shows that Pearl is far superior. This system is a bit too revealing for Pearl but Cinnamon is a different piece of cake; smooth, open, loudspeakers disappear, detail is abundant. The presentation might not be the same but the sound quality level between Supra and Cinnamon is equal. Which you prefer depends on taste. Changing back and forth between Pearl and Cinnamon cables shows again that Pearl is a good and cheaper choice between switches, or with less expensive equipment like the Naim UnitiQute.
Conclusion
It is still surprising that Ethernet cables make a difference to sound quality. I didn’t believe it until I tried for myself. I might have believed that CAT-7 would be superior to UTP (unshielded twisted pair) CAT-5, but differences in sound quality between CAT-7 cables? I am a network supervisor by day and we distribute enormous amounts of data over CAT-5 or CAT-6 cables, over longer lengths than at home, at higher speeds, without any problem.
Beats me why music files differ, but they do! The only explanation I can come up with is that the zero and one values represent a lower and higher voltage in the cable and in the sender or receiver. This is actually an analogue signal when we look at it on a scope. We audiophiles agree that cables sound different with analogue signals, so why not with Ethernet data? Next, any interface for Ethernet has a correction circuit for errors. With many errors this interface has to work hard, that will result in a greater need for current from the power supply and the processor heating up. A bad cable, or one that easily picks up interference, introduces a lot of errors so that might be the cause of a change in sound quality. An Ethernet switch will act like a jitter killer in digital data transport, it separates circuits, stores, re-clocks and forwards data. So a decent switch will do a lot of work to correct errors, but it has no analogue sound circuit on board, that is why it doesn’t matter how much the switch suffers from retries and all kind of errors and interferences. In the end the switch nicely delivers the data to our music system and we have to make sure this last part is error free. We don’t want to use error correction in audio equipment after all.
Thus the cable between the switch and the music player is the most important one. Spend most of your money on that piece of wire. The cables between switches or running to a NAS are less important but they do influence the final results. For budget systems use less expensive CAT-7 cable around your house if you must and put a decent switch next to your music player and NAS. Invest as much as you can in the last metre(s) and the results will amaze you. In Audioquest terms this means Pearl cables around the house, a Cinnamon between the switch and my Naim, maybe an even better cable to my NAD in case I play music from a NAS. If money is no object, use Cinnamon all over the place. And throw away those giveaway cables and the ones you bought in computer stores. They destroy good sound and even if you consider me a fool, I am not fooling you on this one.