When buying do you go for the shortest length needed at present or do you think ahead if components are further apart in the future….
Reason I‘m asking is that I‘m going to dip my toes into ethernet cables. Specifically AQ Vodka and Chord Shawline. I‘ve been using basic cables for years. If I move my switch then i can cope with 0.75m, but that really reduces my flexibility or I go for 1.5m which is a bit too long…. Annoyingly 1m would be ideal for me.
So really up in the air as to which length is best….. I am looking to order 3 cables but I can’t decide on length..
Not answering your question, but iv possible I advise getting on a trial basis in case it doesn’t do as you expect. For that anything from your minimum upwards would suffice.
Apparently with shielded cables they need to be of a certain minimum length in order for the shielding to be most effective, at least with power cables. With Furutech this length starts at 1,5m. I can imagine that the same counts for Ethernet cables. I would go for 1,5m if I were you. Better slightly too long than too short and a pulling force on the connectors.
I’ve found that the quality of the cable (and various other characteristics) matter more than the length. So I think you’d be better off with a better quality 1.5m cable than a lesser .75m one. But it’s good to check the used market for such things. There’s more churn in high end ethernet cables than most original purchasers are likely to admit. Lots of deals to be had you’re patient.
I would go for 1,5m (I did with vodka cable). As tempting as a short lengths is - you are much more flexible with a longer cable. And if I remember correctly a user (think it was @Darkebear ) found out that 1,5m was sounding better that 0,75m.
yes with Ethernet cables with respect to noise power its best to for as long as possible up to 100m. In this regard Cat 5e is better than Cat 6.
Now if your Streamer and Switch supports the Green Ethernet standard in ‘short reach’ mode - then ethernet segment lengths less than 50m have their power reduced so noise power is reduced… but I have rarely seen this ever mentioned on a so called audiophile switch.
indeed… and actually it is pretty much common sense if you think about it, basic Ohm’s law, so hopefully you will be familiar with that - and therefore help minimise any confusion.
Do be wary of marketing claims from some audiophile boutique vendors.. they may quote details that sound impressive, but are not specifically relevant to the use case of reducing actual noise power in the ethernet twisted pairs for home audio to streamers. Always best to look at things from engineering and scientific principles when it comes to such matters - which really helps clarifies a lot of mumbo jumbo. Unfortunately the typical audiophile is I suspect considered a fairly gullible consumer in some regards.
But big caveat, sometimes adding or increasing noise power can make a system sound better - so a very short lead might be less effective at reducing noise power but in turn through coupled noise shaping in the connected devices makes the end result sound ‘better’. You have probably heard me mention this before.
Some of the posts here are rooted in questionably relevant theory rather than actual listening experience.
Any differences between ethernet cables are almost entirely down to their ability to reject radiated RFI noise. This noise does not travel only along the twisted pair conductors, it also travels along the shield of a shielded cable (see below), so shields come with caveats… As audiophiles, we don’t care whether the noise travels along the conductors or the shield or by carrier pigeon, we simply want to stop it reaching the streamer.
Place your switch as close as possible to your streamer to give it the maximum chance to kill the maximum amount of accumulated conducted RFI noise. Attach the two devices using the shortest feasible cable:
NOT shielded ie. Cat 6a, 7 or 8 or anything based on these, because the RFI noise stopped by your switch will simply travel down the shield (the best shields are the best precisely because they are made of the best conductor, usually copper
if you are dipping a toe in the water, so to speak, consider a Melco C100. This is a relatively affordable cable which is shielded but its shield is grounded only to the upstream plug. The shield cannot therefore act as a noise conductor from switch to streamer yet is able to protect the signal from radiated RFI, so reducing the noise reaching the streamer.
If a switch has been introduced to improve sound quality by reducing the amount of noise reaching the DAC via the streamer, rather than simply to provide more ports, then connecting it with say a 100’ = 30m cable is all but guaranteed to make the switch completely useless in its intended role.
It’s not clear in the Cisco documentation, but I have a suspicion this may only apply to gigabit ethernet connections? I cannot get the switch to detect cable length on fast ethernet… maybe I’m doing something wrong. If it does, then for Naim streamers, it may not have any effect.
Now there’s a conundrum… should you even be using shielded cables unless you have an ethernet switch that is properly grounded…
Is it possible to explain that in more detail? I thought the RFI noise on the shield would take the path to ground of least impedance? So if both switch and streamer are grounded, along with the cable, how do we know which ground path the noise will drain down? Obviously with a cable that has the shield connected only at one end it’s a bit more predictable.
Green Ethernet is not based on modulation technology, rather cable length, and so I see it can be supported from 10 Mbps to 10 Gbps subject to the capabilities of the host device.
Additionally many Cisco switches incorporate Time Domain Reflectometers and can report the approximate length of the connected Ethernet twisted pairs and identify fault conditions. But not all Cisco’s switches that have TDRs support Green Ethernet, but most recent Small Business and Catalyst switches apparently do.. and also support the Short Reach function. The function will reduce power on cables less than 50 metres, and 30 metres for 10 Gbps. I believe by default Green Ethernet Short Reach detect is disabled by default on most Cisco devices that support it, so if so you would need to configure the switch to enable it for a particular port.
So for Naim streamers which principally support Fast Ethernet (100 Mbps) then it will be effective for 50 metres or less..
Not with standing for low noise and interference you shoukd avoid earth loops for shields… that is avoid galvanically connecting Earth grounds both ends.. so as you say the single connection is best.
But RF voltages behave very different to DC… so the optimum low impedance path to ground can vary depending on its length. Usually the lowest impedance path will be an odd multiple of quarter wavelength of the RF voltage in question…. so on a broadband of RF voltages there can be multiple low impedance paths to ground… though you can minimise this split of patgs by having a single connection to an effective RF earthing system, but you will get some capacitive coupling leakage.
The primary job of the Ethernet shield is prevent cross talk between cables over longer lengths at higher symbol speeds where they are bundled together. I think in most domestic environments this is moot. Different in a large commercial cable room or equipment room in an office or workshop/favtory.
The cable itself uses twisted paire geometries which is effective within a very short radius around out at cancelling any emissions and resisting any external interference. Twisted pairs start to become less effective in large bundles over distances.
This is one reason we don’t want the shield grounded to both plugs and therefore both devices. Grounding at only the upstream (usually switch) end means no radiated noise picked up by the shield can drain downstream to the streamer.
Thanks, I get that bit, what I wanted more explanation on is the logic of why the switch should be as close as possible to the streamer and how that helps?
The typical listening room is in the typical home which has a good amount of radiated RFI floating around in it. This radiated noise will reach the streamer direct, which is where the streamer’s case comes in - if it is made of a decent conductor like aluminium and has no ventilation holes then it’s going to do a decent job of blocking radiated RFI from reaching its circuitry.
The radiated noise will also reach upstream devices where it can be absorbed and added to the conducted RFI noise exiting the device (router, switch or whatever).
If we place the switch just before the streamer, its galvanic isolation will block a good portion of this radiated-becomes-conducted noise, and the short cable connecting the switch to the streamer is the only opportunity for radiated noise to be picked up afresh.
If we place the switch several metres away from the streamer, it will still block much of the noise as above, but the longer unshielded cable from it to the streamer presents something of an open goal for radiated noise. Yes we could us a shielded cable but this shield then acts as a conductor of noise.
The final piece of the jigsaw is of course the RFI noise generated by any device nearby, and this includes the switch. A true audiophile switch will block accumulated conducted noise through the galvanic isolation in its circuit design, block radiated noise through its case design and generate the smallest possible amount of noise back into the mix as it does its goodness.
Most folk find that even a common or garden network switch, installed in this just-before-the-streamer position makes a positive contribution to sound quality by lowering the noise floor. Despite being far from optimised for audio, its galvanic isolation will do a pretty good job on conducted noise but is typically open to radiated noise (eg. steel case, ventilation holes) and its circuitry and LED drivers will add a slug of noise back into the mix. But overall “net noise” is usually much less than without it in play.
