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Non-foo questions about mains cables

gustav_errata

gustav_errata

pfm Member
I'll say this up front: I am not considering buying a new mains cable for my amp to accomplish any sort of sound-quality improvement. I have read plenty of threads on that and there is no reason to rehash that argument here. My questions are basically about standard electricity concerns.

I am only considering buying a shielded cable. The reason is that my current AV stand has a single small (<10cm diameter) hole through which all cables are routed. Presently that means my power amp's mains cable is basically sitting on the two NACA5 speaker cables where they all pass through this hole (worse, those cables need to squeeze under a shelf, which has maybe 1cm clearance from the bottom of the hole). Maybe one day I'll be able to buy a rack that allows better cable management but it's not in the cards at the moment.

I am also only interested in buying a cable that meets all regulations, notably the CE mark but ideally also the USA UL certification. I don't want any risks. I don't want an insurance liability. To the best of my knowledge, the only shielded cable that is available that has a CE mark is the Supra LoRad series. These come in 1.5mm^2 and 2.5mm^2. I believe Naim amps, such as my own (NAP150), come with 0.75mm^2 cables.

So, my two questions, which I'm positive are elementary, however my searches aren't coming up very successful:

1. I know that a cable that is too small poses a risk of heating up. I vaguely understand that 1.5mm^2 should be sufficient to carry practically any current from a typical amp. Is there any risk from having a cable that is too large for the expected currents? Is there anything extra to consider in this regard with a shielded cable? Again, I want zero risk. I'm of a nervous disposition. :(

2. I don't understand exactly what British Standard 1363 is saying about cable size. Is it that the maximum size permitted in a 13A plug is 1.5mm^2? Or is it that the maximum size that a 13A plug is required to fit by design is 1.5mm^2?
 
1. No, nothing to worry about at all. Assuming the shield is connected to earth it should actually be safer in theory, but in this application that should be of little consequence.

2. Do you mean. "Provision shall be made for the entry and effective clamping without bending of 2-core and 3-core flexible cords for rewirable plugs as given in Table 11, Table 12, Table 13, Table 26 and Table 27 of BS 6500:2000, having nominal conductor cross-sectional areas not exceeding 1.5 mm2" Yes that is a design requirement, the plug must be designed to safely accommodate the flat and round flexible cords described in those tables up to 1.5mm2. It is not advisable to use a heavier cable with a rewirable plug unless you know the manufacturer has designed it to accommodate that, whether there is ever any point to using a larger flex is debatable, but several companies sell assembled cables using them and it isn't illegal or problematic.
 
misterdog said:
Note that such cables are far less flexible and may struggle in your limited access hole.
Click to expand...

Thanks, noted. Although the Supra ones do appear to be reasonably flexible. It was necessary to attain the CE mark (according to their own promo material, at least).

I'll see what options I have for drilling a hole. Hole saw attachments don't look too expensive. Of course, once through their respective holes, the mains cable and the speaker cables will still be in relatively close proximity.
 
The Furutech Roxy has a slim connecting plug for the amp end and is solidly constructed. It is also shielded.

You will see many diy'ers and constructors use their cables and connectors.

I know you are not interested but it sounds better too.
 
Bairnstorm said:
it sounds better too.
Click to expand...

Insulator: Audio grade polyethylene (red yellow green)
Intervention: Cotton yarn
Presser winding: Special paper tape

LOL.

Yarn - tell a long or implausible story.

Greater extension at both low and high frequencies delivers clears and dynamic imagery in an ultra-quiet soundstage.
Click to expand...

Such claims could be easily measured
 
gustav_errata said:
Thanks, noted. Although the Supra ones do appear to be reasonably flexible. It was necessary to attain the CE mark (according to their own promo material, at least).

I'll see what options I have for drilling a hole. Hole saw attachments don't look too expensive. Of course, once through their respective holes, the mains cable and the speaker cables will still be in relatively close proximity.
Click to expand...
The Supra Lorad is indeed flexible even by normal non-hi-fi standards - when not in use I coil them quite tightly with no problem.
 
misterdog said:
Insulator: Audio grade polyethylene (red yellow green)
Intervention: Cotton yarn
Presser winding: Special paper tape

LOL.

Yarn - tell a long or implausible story.



Such claims could be easily measured
Click to expand...
Speaking of intervention, that describes the construction of most any twisted multi-core mains flex produced since WWII, when polyethylene was first recognized as being an effective electrical/signal cable insulator (enough so, for its use as such to be kept a secret until after the war).
 
Bairnstorm said:
The Furutech Roxy has a slim connecting plug for the amp end and is solidly constructed. It is also shielded.

You will see many diy'ers and constructors use their cables and connectors.

I know you are not interested but it sounds better too.
Click to expand...

Thanks, but the Furutech cable is way out of my budget. It looks to be about the same as I spent on my (second-hand) power amp. I'm still at the stage where only unambiguous improvements due to component upgrades are under consideration. I think I'm better off not considering expensive tweaks yet.

I also mainly wanted to avoid the usual arguments here about mains cables. We've all read them before.

Here my main interest was in electrical safety for numpties, with a dash of noise due to poor cable-run conditions.

If anyone is willing to go off-topic, I would be interested to hear from people who happily use non CE/UL-certified mains cables and whether or not they were emotionally scarred as a child by a seemingly endless stream of filmstrips shown at school about how their house was most definitely going to burn down from an electrical fire and how, as a 6 year old, they should have already drawn up a fire-escape plan and discussed it with their parents.
 
I' m not really sure what you want then. I have no idea if any of my power cords are CE. I have 2 Kimber, 1 Chord and the Furutech nor do I lie awake worrying about the house burning down.

Buy the Supra if you want but if you are not interested in sound quality, what is the point? Save up for a better amp.
 
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