question on pwr cords


Does the length of a power cord impact sound quality greatly? Obviously analogue interconnect, especialy when single ended and speaker cable do....the reason is due to my lack of outlets and positioning of equipment considering ordering a custom length power cord for a pwr amp.

In addition if I want a less obstrusive, less thick pwr cord, what would u recommend? Cost is less of an issue. Crystal ultra?
henryhk
Yeah, I've always wondered how 6' of power cable from the wall outlet to your component could make any difference since the power came to your house thru several miles of cable already. But there are plenty of guys on this forum who will SWEAR that the last 6' make a HUGE difference - not subtle.

And, don't forget to install anti-resonant wall plates, they also make a HUGE difference...[smile]

-RW-
newbee -- first let me answer your specific question: no there's probably not going to be much difference between a 1.5 and say even a 6.5 meter cord of identical construction. As you get longer than twenty feet though, there IS going to be voltage drop, so if one can go up by a wire size, that's a good thing.

What I meant was, that ALL amps should use 10AWG (even if they're not that high powered) because the name of the game with amps (and apparently DACs for some reason) is energy TRANSFER. This is what Jim Aud of Purist has always emphasized, and why his PCs are among the best sounding.

His Dominus PC is an effective 9AWG and I think PS Audio even makes a 6 or an 8 AWG PC! And this ALWAYS raises the question we've heard a million times: "what's the point of using a PC that has bigger conductors than the ones in your wall?"

The answer is that they do different things. The wall wiring is like a resevoir of AC. The hot conductor is just sitting there cycling from plus to minus looking for a ground. It's sort of like a big river flowing past your outlet, and all of a sudden, you stick a power cord on it or in it (like a water wheel) to get some of this flowing energy. Now, there's lots of potential energy stored in those wall conductors, even if they're not that big, because they have the reserve (inertia) provided by the entire wiring system. So if you can stick a big enough pipe into the stream, you can use it and return it back to the stream (complete the circuit) without any bottlenecks.

I guess what I'm trying to say is that the large conductors of a PC have a different function than the size of the wire in the wall. The wires in the wall just have to carry their assigned amperage without getting hot and burning down the house. The PC has to grab that energy, use it (spin the water wheel) and return it to the river without any traffic jams.

Even a lower powered amp has constantly fluctuating energy requirements, every microsecond, so it's important that it can get exactly what it requires and then return the power to ground without encountering resistance, AC intermodulation distortion (a big problem with small conductors on med to hi powered equipment), inductance and other impediments that build up in smaller conductors.

Again, with PCs, if "quick and clean" energy transfer is accomplished, power handling capacity is pretty much automatically taken care of.
.
Nsgarch, Thank you for your explanation about function of the home electrical system vs the power cord. I, too always wondered why I needed a power cord of a thicker guage than the house wiring. I do hear a difference with an aftermarket PC vs oem, just didn't know why. Your explanation makes it crystal clear. Thanks!
Nsgarch,
Very good explanation, one of the best I read, you nailed it !!
I experienced EXACTLY what you describe of the large (10 awg. or greater) on my DAC and *today* my mono amps.
The "reserves" are there, just waiting to be hammered out, providing of course, the PC is well designed, quiet and unimpeded.
The music "pours out like a river" in my system.
Sorry for hi-jackin this thread somewhat.
And while we're on the subject of OEM PCs, most of them aren't that bad. For one thing, the conductors are WELDED to the plugs before the molded casing goes on, so it's a great connection, but usually they are about one or two conductor sizes too small for my taste.

The second problem is that they are (generally) unshielded; although in defense of the manufacturer, let me explain that if they WERE shielded, the shield would have to be connected to the ground pin of the plugs AT EACH END! Otherwise, the manufacturer couldn't get UL Approval on his product. If the shield IS connected at BOTH ends, guess what?? You have a giant ground loop!! So even though all digital equipment (DACs, processors, CDPs) should be supplied with shielded power cords to keep them from radiating digital RFI (hash) into the air, they usually aren't, and so OEM cords on that kind of equipment should always be replaced IMO with PCs that have a "floating" shield (only connected to the ground pin at the AC plug end.)

For the DIY inclined, if you got a shielded OEM cord with your digital equipment (it'll say so on the jacket), then do this: cut off the IEC connector and strip back the jacket AND THE SHIELD an inch or so. Slide some matching black shrink tubing over it and connect the conductors to a new IEC plug of good quality. Voila! You have an OEM PC with a floating shield!
.
.