Is there a optimum lenght for power cables?


I've followed the debates on cable lenghts for IC's and speaker cables. The shorter the better on speaker cables seems to make sense. IC any reasonable lenght will not impact the signal. What about power cords? I had a dealer tell me that they should be no less than 2 meters. Looking for comments has anyone else heard this and if true can you please explain why. I am looking to purchase after market PC's and would prefer shorter because my equipment is near dedicated out lets so I don't need long cords 1 meter will due. Besides the back of my rack is starting to look like a cable jungle. Thanks in advance.
walkelin
Wheres the science in all this?Its not there thats the problem.Nothing more than a manufacturing ploy to make us spend more money with absolutly no proff of science to back up the idea that a length of cable, long or short will sound better or worse. If you can save a buck keep it in your pocket, because short is good & cheap.
Your dealer is full of sh!t, to put it bluntly. Explain then why 1.5 meters is the most common length. He's just trying to make more money.
I don't know that there is an optimum length. I've noticed MUCH more difference between different power cord designs and materials than I have between lengths. FWIW, I don't own any 1 meter lengths, but I do own a few 4 foot power cords. The only thing with shorter power cords is that they need to be more flexible. Short AND stiff is a bad combination for power cords.

Also, after talking with many cable manufacturers, it seems like that 'the shorter is better' formula for speaker cables has expired. Most manufacturers today will not sell speaker cables less than 6 feet in length. They now say that 6 feet is the minimum length for molecular stabilization. Or maybe a 3 foot pair just doesn't cost enough. You be the judge.

John
"They now say that 6 feet is the minimum length for molecular stabilization.". I worry a lot about the unstable molecules on my ic's and pets and never trust any person under 6 feet tall :).
I'm a cable mfg. I would have to agree with you guys. I've tried and I'll be darned if I can hear one bit of difference between a cable of different lengths. I think just get the shortest cable that will work for your system is the best bet. This just makes for less of a mess, a clean looking system and offers less chance for interference. Otherwise, I believe, there is no reason for them to try and sell you a longer cable other than profit. Of course this is just IMHO.

Jeff, that's funny! And don't trust me as I'm only 5 10"!! :)

Sincerely,
John
My monoblocks are connected with three foot biwire. Whew! I guess that qualifies as six feet.
Lol! Don't fall for the dealer's nonsense.

Learn how to terminate your own power cables, as I did, and make them the exact length to avoid the cable jungle. I have power cords from 1' to 5' in my system and to my "golden ears" they all sound the same.

If you don't want to terminate your own, there is usually a guy in your town who will do it for you for a reasonable fee. Many manufacturers will also provide custom lengths.
All your power cords need to be of unequal length, so the magnetic radiational patterns don't overlap and contribute to an increased electron pull, which is directly related to molecular stabilization. Of course, this increased electron pull is directly associated w/the increased gravitational pull of the moons cycles, so you can only use longer PC's in those periods near a full moon.

You can trust me, as I'm 6' when I'm wearing boots
How did Abe Lincoln respond when there was a remark made about his long legs: They're long enough to reach the ground, that's all that I care about.

I think that the best size power cord reachs the outlet nicely, taking the flexibility and everything else into consideration.
The optimum length is long enough to reach from the component to the power outlet.

"Molecular stabilization" - Ha, ha, ha, gimme a break! More like "bank account accentuation"...

-RW-
FWIW, if you buy your PC for its benefits as a 'filter' or 'tone control' then longer is better is, IMHO, a logical conclusion. I typically use 6 and 9 foot lengths for convenicence, especially the 9 footers for mono amps with short speaker cables. Looks better than HD orange wire. :-)
When I first started buying mice cables I got the shortest ones possiable. Later as I changed things I found I always needed longer ones. Now I never buy any cable under 1.5M (2M is a good standard). Its easier to have some extra length then rebuy cables. But thats also because I seem to change things around every year. I doubt I could hear the diffrence between a 1M and 4M quality powercord.
It's unlikely that shortest is best for power cords.

Most power cords (PCs) passively filter high frequency noise (e.g., in the kHz to MHz range) by acting as a distributed capacitor. Here's how it works:

A capacitor acts as a high pass filter. The text book equation for capacitance's role in impedance (resistance to AC) is: Xc = 1 / (2*pi*f*C). Notice that both the frequency (f) and the amount of capacitance (C) are in the denominator, so as the product increases (i.e., more capacitance or a higher frequency), then there is less of a resistance (strictly: impedance) to those frequency components of the wave. 'pi' is the constant 3.14159… . So if you would put a capacitor between the hot and neutral lines, high frequencies would "short" across, but low frequencies (e.g., the 60 Hz fundamental wave) would be left intact. This is the mechanism behind the "Auricap tweak".

In PCs, various geometries (e.g., twisted pairs) and dielectrics (i.e., the type and thickness of the insulation on the individuals wires) are used to establish the cable's capacitance. By bringing the hot and neutral into close physical contact, capacitance is created between them. High frequency noise on the hot wire will "short" across the insulation to the neutral (and of course vice-versa; remember in AC, the "hot" has a voltage [potential], but both wires carry current). The "short" doesn't cause a problem because the voltage and current at those frequencies are so low that the excess energy is easily and safely dissipated as heat.

Clearly, the tighter the hot and neutral wires are twisted in close contact, or the thinner the insulation, or **the longer the length of contact**, the higher the total capacitance. So if you replace a 2 m cable w/ one that is only 1 m, you've cut the capacitance--and the cable's ability to filter--in half.

Does that mean longer is better? Not necessarily. If the cable is too long, you may need to wrap it upon itself--raising the inductance and reducing the capacitance--or it may fall near other PCs--creating electromagnetic interference on both cables. But it certainly means that there really can be a notion of "too short". "Too short" is that length such that the cable's capacitance is insufficient to adequately filter the high frequency noise on your line.

Maybe "more capacitance" isn't right for your system--though it is hard to see how on a PC it could harm the sound. Basically, even with clean power, extra PC capacitance should simply result in no observable effect, because if there is nothing to filter in the kHz and MHz range, it shouldn't effect the 60 Hz wave. Note: this also means that that PCs--and really all passive power filters--can really do nothing about low frequency harmonics; for that you need active filtering. So you cannot achieve totally clean power with only passive devices unless your power already has no low frequency harmonics (unlikely).

For speaker cables, we are not interested in filtering a 60 Hz fundamental, but rather in preserving 20 Hz – 20 kHz range given "modest" voltage and current capacities; for interconnects, the frequency range is the same as for a speaker cable, but the current is far lower than the voltage, so capacitance is a real issue (read: bad). So all three cable applications require notably different considerations.
How far is it to your utilitie's power plant? I'd say maybe 200, 300 miles up to about 1,200 here in Quebec.
It depends on what the meaning of "is" is.

With respect to one of our former presidents.