How do power leads make a difference to sound?

[Boscoe]

I've been looking through of HiFi forums recently only to discover the rediculas discussions on offer. Like how different power leads make a difference to the sound of your system? I mean how does it? There is no electronic theory explanation is there?

I love of this diy community is immune to this pointless and stupid topics like these!

[DF96]

Possible explanations:
1. they don't make any difference.
2. they affect the amount of RF pickup, which can affect unfiltered equipment.
3. they have a marginal effect on charging pulse shape and hence harmonic generation.

I will leave the 'true believers' to offer their alternative explanations. Given the miles of cable from the power station, and hundreds of metres from the local supply transformer, and tens of metres within the house, it is astonishingly unlikely that any significant change can be effected by the last two metres!

[Boscoe]

Originally Posted by DF96

Possible explanations:
1. they don't make any difference.
2. they affect the amount of RF pickup, which can affect unfiltered equipment.
3. they have a marginal effect on charging pulse shape and hence harmonic generation.

I will leave the 'true believers' to offer their alternative explanations. Given the miles of cable from the power station, and hundreds of metres from the local supply transformer, and tens of metres within the house, it is astonishingly unlikely that any significant change can be effected by the last two metres!

I'm sure the very little changed by the last two meters won't compare to the things connected to it and where they are in the room and such.

[stormsonic]

4. all cables have real components like resistance, inductance and capacitance. Therefore cable will act as filter (or as pickup) and last two metres of cable are much more important than hundreds of meters before.

Differences are audible and expensive cables are not always better.
But no power cord can transform your POC amp to the SOTA amp

[digits]

They always sound better to the guy that paid for it all... or he'd go nuts.

[DF96]

last two metres of cable are much more important than hundreds of meters before

Why? This could just about be true if the main problem was high microwave pickup which was attenuated quickly by lossy PVC insulation. Then the last 0.5m might matter. To improve things we could choose an even worse dielectric.

[simon7000]

If you care to measure 1/3 to 1/2 of the total AC power line resistance is in the power cord and connectors!

But it is mostly the RF filtering that can be done in a cord without increasing power loss as an inductor would do that is the biggest asset.

[bbggg]

Originally Posted by stormsonic

cable will act as filter (or as pickup) and last two metres of cable are much more important than hundreds of meters before

But far less important than the power supply that follows.

[DF96]

But how does that compare with the transformer resistance? In most cases probably negligible. However, a high mains lead resistance will help reduce current rise times and so reduce mains harmonic generation. Use the thinnest lead which will not melt with the current! (OK, I'm not being entirely serious - we are talking about a very marginal effect).

[simon7000]

Originally Posted by DF96

But how does that compare with the transformer resistance? In most cases probably negligible. However, a high mains lead resistance will help reduce current rise times and so reduce mains harmonic generation. Use the thinnest lead which will not melt with the current! (OK, I'm not being entirely serious - we are talking about a very marginal effect).

The transformer resistance is inside the magnetic loop and has less of an effect than circuit theory would show.