mains cables - please help me out

[julesd68]

I notice that a substantial number of forum members have invested not inconsiderable sums of money in mains cables. I really cannot get my head round it all but I have never tried anything more expensive than a Supra lo-rad in my system, so I am certainly not in a position to make any kind of analysis myself.

The question is - what does an expensive mains cable do that a cheap one doesn't?

How can a mains cable give you "tauter bass" for example if all it does is to lower "noise levels" from the mains? :scratch:

[realysm42]

Removing noise allows what shoudl be there to speak to you properly.

Imagine trying to hear someone talk to you in a room full of other people; if they can be silenced, you'll hear that one person a lot better.

I'm not sure if that's the proper technical answer but it's how I understand it.

Also, price isn't necessarily indicative of quality, real upgrades to sound can be had from just a small investment; I replaced all of my generic kettle leads in my system with these:

http://www.mains-cables-r-us.co.uk/mains-cables-/143-the-audio-asylum-mains-power-cord.html

and got a great boost to the sound :)

[John]

If you want I come round and hear for yourself
Systems very to the degree they respond to them

[Reid Malenfant]

How can a mains cable give you "tauter bass" for example if all it does is to lower "noise levels" from the mains? :scratch:
Most decent aftermarket cables actually use a much bigger conductor area than even a 13A mains cable, which is 1.25mm². For instance, the Mark Grant DSP2.5 stuff I use a lot of here happens to have conductors of 2.5mm² cross sectional area.

In other words the cable has a much lower resistance! You may not think this is very important as your amp may only draw a couple of Amps, but it's the way it draws that current that matters :eyebrows:

An amplifier will only draw current from the mains on AC voltage peaks, because it's recharging the capacitor bank in the amp. This means that while it may draw a few Amps average, it's actually drawing peak currents of maybe 50Amps or more...

This is where having that nice thick mains cable makes a difference to the solidity of the bass - where most power is used :cool:

[DSJR]

If a big amp was drawing 50A or more, wouldn't the house circuit trip out in the fusebox? Forgive me, I'm ignorant on such things.

By the way, a cheap 2.5mm mains cable could be one of the double insulated speaker cables out there, two well insulated conductors but with an outer jacket on top? No doubt someone will come along and tell me why it's unsafe to do this, but a good gauge mains cable makes a great cheap speaker wire :lol:

[MCRU]

If a big amp was drawing 50A or more, wouldn't the house circuit trip out in the fusebox? Forgive me, I'm ignorant on such things.

By the way, a cheap 2.5mm mains cable could be one of the double insulated speaker cables out there, two well insulated conductors but with an outer jacket on top? No doubt someone will come along and tell me why it's unsafe to do this, but a good gauge mains cable makes a great cheap speaker wire :lol:


Quite correct, belden 19364 mains cable is a good speaker cable! Russ Abbott sells mains leads made from kimber speaker cable with an earth wire down the middle does he not?

[DSJR]

Yeah, but the woven conductors are covered in an outer jacket if my old RA mains cable is anything to go by - fine for sonny-jim's PC, but not good enough for the HiFi I found ;)

[Mr Kipling]

If a big amp was drawing 50A or more, wouldn't the house circuit trip out in the fusebox? Forgive me, I'm ignorant on such things.

By the way, a cheap 2.5mm mains cable could be one of the double insulated speaker cables out there, two well insulated conductors but with an outer jacket on top? No doubt someone will come along and tell me why it's unsafe to do this, but a good gauge mains cable makes a great cheap speaker wire :lol:

'80s Jimmy Hughes "Top Tip": 2.5 mains two-core and earth makes a great speaker cable. Can even use it on your LP12.

Kind Regards,
Stephen

[MCRU]

Here are some I made earlier....:)

http://i622.photobucket.com/albums/tt309/themainsman/ALL%20MCRU%20POWER%20LEADS/cd04ee16.jpg

[Reid Malenfant]

If a big amp was drawing 50A or more, wouldn't the house circuit trip out in the fusebox? Forgive me, I'm ignorant on such things.

No, as I said, if you average the current drawn over the whole 10 milli second time period it's quite low. But as it's effectively drawing on the mains voltage peaks, maybe for less than 500 micro seconds, these current peaks are high.

While they may be high, they aren't over enough time to blow a fuse or trip a breaker :)

[Mr Kipling]

No, as I said, if you average the current drawn over the whole 10 milli second time period it's quite low. But as it's effectively drawing on the mains voltage peaks, maybe for less than 500 micro seconds, these current peaks are high.

While they may be high, they aren't over enough time to blow a fuse or trip a breaker :)

Hi Mark,

Do you know if circuit breakers are any more linear in operation than fuses?

Kind Regards,
Stephen

[Welder]

Most decent aftermarket cables actually use a much bigger conductor area than even a 13A mains cable, which is 1.25mm². For instance, the Mark Grant DSP2.5 stuff I use a lot of here happens to have conductors of 2.5mm² cross sectional area.

In other words the cable has a much lower resistance! You may not think this is very important as your amp may only draw a couple of Amps, but it's the way it draws that current that matters :eyebrows:

An amplifier will only draw current from the mains on AC voltage peaks, because it's recharging the capacitor bank in the amp. This means that while it may draw a few Amps average, it's actually drawing peak currents of maybe 50Amps or more...

This is where having that nice thick mains cable makes a difference to the solidity of the bass - where most power is used :cool:

I just don't understand why having a larger diameter conductor than that of the supply makes a difference. :scratch:

[Reid Malenfant]

I'm not sure what you mean by linear, though you this may help?

There are different types of breakers, though in this instance i'm talking about MCBs or mechanical circuit breakers, not RCDs.

There are three different curves which will result in how they behave under an overload & over time. These are known as B, C & D curves.

Type B breakers won't like a high peak overload, these should be used on something like a resistive load, like an immersion heater or shower.

Type C breakers will handle a high current peak for a short duration when something is switched on, most mains rings will probably be fitted with type C breakers.

Type D will handle huge current peaks when something is switched on, these aren't generally used in domestic environments.


All the breakers will likely carry 125% overload for a minute or two, the higher the overload, the shorter the duration that each will keep the circuit connected.


As to which is more linear,a fuse or a breaker, I'm not sure :scratch: But a breaker can be reset :D


I also wouldn't go too much on what I have said here, as I'm not an electrician :lol: Any in the place can greatfully correct me if I'm in the slightest bit incorrect.

[Reid Malenfant]

I just don't understand why having a larger diameter conductor than that of the supply makes a difference. :scratch:
John, most houses have mains rings :)

That means you have a 5mm² cable feeding your mains socket (2 x 2.5mm²).

[Mr Kipling]

I'm not sure what you mean by linear, though you this may help?

There are different types of breakers, though in this instance i'm talking about MCBs or mechanical circuit breakers, not RCDs.

There are three different curves which will result in how they behave under an overload & over time. These are known as B, C & D curves.

Type B breakers won't like a high peak overload, these should be used on something like a resistive load, like an immersion heater or shower.

Type C breakers will handle a high current peak for a short duration when something is switched on, most mains rings will probably be fitted with type C breakers.

Type D will handle huge current peaks when something is switched on, these aren't generally used in domestic environments.


All the breakers will likely carry 125% overload for a minute or two, the higher the overload, the shorter the duration that each will keep the circuit connected.


As to which is more linear,a fuse or a breaker, I'm not sure :scratch: But a breaker can be reset :D


I also wouldn't go too much on what I have said here, as I'm not an electrician :lol: Any in the place can greatfully correct me if I'm in the slightest bit incorrect.
Thanks.

I want to make a distribution block using copper busbars and avoid using plugs and sockets. Also wanted to avoid fuses and naturally some have said its not a good idea. Wondered if circuit breakers would be a better option, which is why I asked.

Thanks again,
Stephen

[Reid Malenfant]

Better IMHO, though more expensive at the outset.

I'll be using them myself when I upgrade the spur to this room :)

[MCRU]

Thanks.

I want to make a distribution block using copper busbars and avoid using plugs and sockets. Also wanted to avoid fuses and naturally some have said its not a good idea. Wondered if circuit breakers would be a better option, which is why I asked.

Thanks again,
Stephen

Far simpler to buy a schuko mains block with a uk plug on the end and fit schuko plugs to all your mains leads, that is perfectly legal and safe as the mains plug on the end of the schuko block has a fuse fitted

ben duncan makes similar to what you require on the moth website, a metal box with 12 outlets, just wire your mains leads into it

[Mr Kipling]

Far simpler to buy a schuko mains block with a uk plug on the end and fit schuko plugs to all your mains leads, that is perfectly legal and safe as the mains plug on the end of the schuko block has a fuse fitted

ben duncan makes similar to what you require on the moth website, a metal box with 12 outlets, just wire your mains leads into it

Thanks for that David.

Kind Regards,
Stephen

[Welder]

John, most houses have mains rings :)

That means you have a 5mm² cable feeding your mains socket (2 x 2.5mm²).

Yes but……
First, I’m not arguing whether ‘upgrading’ the mains supply makes a difference or not.
I’ve done enough work on mine to draw my own conclusions and that’s all that’s all that matters.

What I’m having problems with is if I’ve understood you right is any sonic improvements one might hear are attributable to the larger diameter wire being able to handle peak current.
I’ve got 2.5mm conductors going right up to the components. The trouble is, the component wiring isn’t anything like 2.5mm. In fact, some of the wires on the power supply side of my amplifiers for example are 1mm diameter or less.
If the ‘technical’ explanation you seem to be putting forward is correct then even if the extra diameter of the ‘upgrade’ cable handles peak current draw better, it all just goes to shit when it reaches component level. :scratch:

[bobbasrah]

Perhaps I'm being a bit thick here, but considering the role of the smoothing caps is to handle short peak current demands, then would the bottleneck not be the rectifier and transformer stages and the wiring in the kit irrespective of how quickly current from mains can be supplied?

I can understand where getting a noise free low-impedance mains aupply would have benefits where there is a lot up crap flying.

[NRG]

A cap input supply will pulse the mains 3x or more the psu rating at twice the mains F, so a 3amp supply could see over 9amp peak current pulses on the mains. This can affect other devices attached to the same supply, it can also cause a power factor issue for the power companies.

[bobbasrah]

A cap input supply will pulse the mains 3x or more the psu rating at twice the mains F, so a 3amp supply could see over 9amp peak current pulses on the mains. This can affect other devices attached to the same supply, it can also cause a power factor issue for the power companies.

Sorry Neal you've lost me....
Are you referring to the smoothing caps after transformation and rectification having such an effect back through rectifier and trafo ?:scratch:

[NRG]

Yes but I was off a bit its up to 6x the average load current, so a 100W amp delivering into an 8 Ohm load could pulse the mains TX and associated wiring / ring mains with up to 21amps.... Source: Morgan Jones / Ron Elliot

[julesd68]

:confused: All well over my head - it feels like all of you have degrees in electronics!

I think the only course of action is to buy a mains cable from MCRU David or Mark Grant and see what happens!!

[bobbasrah]

Yes but I was off a bit its up to 6x the average load current, so a 100W amp delivering into an 8 Ohm load could pulse the mains TX and associated wiring / ring mains with up to 21amps.... Source: Morgan Jones / Ron Elliot

Sorry Jules, as for the degree, I believe it was in Fahrenheit way back then....:D
Average kicking 21A demand on the ring? You have to be shitting me, seriously from a 100w amp???? Pulsing back through the rectifier and transformer etc ?:scratch:

[NRG]

Up too, MJ found it to be about approx. 5x but qualified it with a range of 4 to 6. The current spikes are far greater than the average current draw.

[MartinT]

Average kicking 21A demand on the ring? You have to be shitting me, seriously from a 100w amp???? Pulsing back through the rectifier and transformer etc ?:scratch:

These are short term pulses but yes, they will be the demand made by the amplifier. Now add all the pulses generated by other components in the system. You can see that even though these are momentary spikes, that very large current demand is really happening and any impedance caused by the wiring will contribute towards dampening the response to demand and allowing the PSU voltage to sag. More amplifier power (higher volume) will widen the current peaks and the sag.