question on pwr cords

Once you go beyond 1.5 m from the wall, you must use 10AWG or larger conductors to maintain good energy transfer -- especially for a power amp.

Unfortunately, that rules out anything 'unobtrusive', except for the Aural Thrills "Silver Big One", or the "Triple 10" which are both 10AWG and only about 3/8" in diameter.

http://www.auralthrillsaudio.com/SBO.htm

I have three of them on my Martin Logan electrostats and Depth subwoofer. Great product beautifully crafted. You can speak with Tom Kenny if you need special lengths. Note: although they are VERY unobtrusive (small) they are kind of stiff, so straight runs and gentle curves are necessary.
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You don't give an indication as to how long you are looking at, but, remember, you could run into safety issues if the powercord is too long.

Best keep them short and go for longer speaker cables or interconnects.

"Once you go beyond 1.5m...."

Nsgarch, Can you explain why that is so? Are there any studies supporting this or is is it an anecdotal thing?

What would the aural differences be between (lets for the sake of discussion say) 4 meter lengths of 14 gauge, 12 gauge and 10 gauge cable?

usually best results are achieved if the cables are long enough to reach teh socket... please! you are never going to here the difference between a 1.5m cable and a 2m cable of the same type. stop worrying and listen to the effing music!

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.
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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!
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Please forgive my ignorance, but, shouldn't that 3 prong power cord that has the ground attached at both ends be draining that to the outlet?

Unsound, your question isn't quite clear to me. All three conductors in a power cord are connected to the plug at each end. One to hot, one to neutral and one to ground. If, in addition, the cord has a shield (usually a metal "braided tube" right under the outer jacket and surrounding the three conductors) it will capture any stray RFI in the air and drain "it" to ground, by connecting the shield to the ground pin of the AC plug.

As long as the shield is ONLY connected at ONE END (the ground pin of the AC plug) it cannot conduct any current (like from one end of the cord to the other.) If however, it's connected to the ground pin of the IEC plug as well, then you have two separate but connected "wires" (the shield-wire, and the ground conductor-wire) connected together at each end of the PC. If you draw a diagram of this, it's what's called (in circuit terminology) a loop -- in this case a "ground" loop. It can then act as an antenna that will pick up electromagnetic radiation (mostly 60 cycle AC from the cord itself, or other nearby sources of AC) and you get devilish hum.

Some PCs (like Cardas for instance) employ a double floating shield. There are two concentric shields (insulated from each other) and one is connected to the AC plug ground pin (only), and the other is connected to the IEC ground pin (only) and I guess that's about as good as it gets ;--)
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Blakeaudio,

I can hear the difference between a 1.5 and 2 meter power cable of the same type, and so can you, if you'd try it.

Also Nsgarch, not all CDP's and DACS sound better with 10awg or heavier PC's. Some, maybe even most, do, but not all. A friend has a modded Sony SACD player that sounds best with 11-12 awg PC's. I've also owned some DSP units that only sounded 'right' with their original PC's, which were only 16 awg. Why? I wish I knew for sure. :)

I am looking at about 9ft required (from current 3ft) as a reuslt of set chg so I guess that length expansion in itself will not be an issue.

On the unobtrusive....I have heard the Crystal Ultra interconnects and despite being very thin, they sound very impressive indeed...guess pwr cords are different? Did notice the do produce a thinnish looking pwr cord which they term reference so was interested...aslo aren't Nordost's Valahalla pwr cords less obstrusive than the norm? Also, Jena labs cable?

I currently use Shunyata, and I do like them but they are big pythons that are creating a bit of WAF issues...

Tplavas,

I have to say that I'm amazed at your aural accuity! Just how does the difference that you can detect between a 1.5 and a 2 meter PC of ths same brand and construction manifest itself? What is it that you hear that is different? Do you think that this observation is universal, that is it applies to all amps, or just yours?

I'm facinated.

Newbee:
That's an easy one, the 2m PC gets you 0.5m closer to the music....
sorry couldn't resist..

Newbee,

I'll assume that you weren't being sarcastic with your question and give you an answer.
It depends on the specific power cable, but even small changes in length can be heard. Again, it varies depending on cable design, but generally the shorter the power cable gets, the more 'forward' the sound, along with some perceived movement in the soundstage. With some PC's, this difference can be pretty drastic, most likely because of their fairly high inductance (compared to the 'average' PC). Heavy-gauge PC's with lower inductance tend to minimize the change in sound with length.
I don't think it's a coincidence that most of the positively reviewed, well-known power cords I've tried sound best in lengths between 5-8 feet (in my opinion). I'm sure most successful PC manufacturers consider the sonic effects of length when designing their power cords.
Frankly, I'm always quite surprised at the jeering that takes place every time someone brings up the subject of power cord length. If one believes that PC's make a difference, why is it so hard to believe that their length affects a difference as well?

Tplavas, I wasn't being sarcastic, but I will comment on your last sentence.

It is not, or at least IMHO should not be, a matter of whether or not one 'believes' that PC's make a difference. A person should simply be able to clearly hear a difference if one exists. I've never been able to clearly hear a definable difference and I'm always interested in how folks who do hear a difference describe that difference.

That way, next time I try experimenting with PC's I know what to listen for. I know cables and IC's can sound different depending on design and usage, why not PC's. I just haven't heard it, yet.

Tvad, Thanks for the advise. I do just that but I think that the changes might be subtle enuf to be obscured by the 2d order harmonics of all those tubes in my systems. Besides its more fun to change tubes than PC's. :-)

Got a question for the 'power cord' experts. Is perhaps the reason that I have not been able to hear a meaningful difference in different heavy guage PC's due to the adequacy of the power supplies in my amps, pre amps, etc or is that not an issue?

Newbee,
I'll agree with Tvad, the power supply of a component won't prohibit if from being affected by it's power cord, although it does have some effect IME. I've had components with 2Kva transformers that were practically 'transparent' to sonic signatures of PC's, and mass-market stuff that only likes the cheapie PC that came in it's box.
In the very first iteration of my system, I tried a couple of PC's (TARA labs and Virtual Dynamics) and didn't hear enough of a difference to convince me I was hearing anything at all. The biggest sonic difference between that system and my current setup is the quality of the bass and mid-bass, and the quality and quantity of midrange dynamics. That early setup was pretty poor at differentiating bass notes, and most of it's dynamics were heard as upper-midrange harmonics, focused on the leading edges of notes, and weak on the follow-up. My current setup is better in all those respects, before any AC 'enhancements' are employed, and far, far, better after.

I actually recently experimented with different length power cords.

Having several Virtual Dynamics david power cords in my system I decided to let my ears determine if some longer Davids would have sonic improvments to shorter Davids.

I took the 5 foot Davids that where on my cd and amp and swapted them out with the exact same Davids (all bought and made at the same time) that where 7 foot and where on my subs.

I heard a nice improvement. The sound was more focused and better positioning of instruments when going to the 7 foot for my cd and amp from the 5 foot.

I just talked to Rick Shultz of Virtual Dynamics yesterday and told him my results. Now Rick's power cords have resonance control inside the cable and he told me that the couple extra feet added extra vibration control to the signal. I am sure theres other reasons for the change in sonic be it for better or worse, though in my system with Ricks cables it was for the better.

Rather than start my own thread on what I need, I think this is an appropriate place: I have Harmonix Studio Masters on both my SET pre and cdp. My SET amp is right in front of the outlet. I need only .5m at the most. Any suggestions? Flexibility is important at such close proximity. I suppose I could move up to a 1m if the power cord is very flexible. I can't spend the $$ on this power cord like the Harmonix. At least, not with this wife. I know, I know, but I love her. thanks guys. warren :)

For something that short, the only really important thing is good stranded 10 AWG copper (twisted) and decent plugs (AC and IEC) If I were you, I'd make one myself with parts available from one of the many PC mnufacturers here on Agon that provide DIY parts.
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For something that short. You mean if it is one foot longer, that will require spending oodles of dough? I don't understand. Anyway, I'm not into building any cord. Recommendations of an inexpensive 10 gauge, flexible copper twisted?

Warren, the fellow I have in mind is Chris venHaus. His website is:

http://www.venhaus1.com/diymains.html

He also makes cords to order quite reasonably if you're not into DIY. My point about "that short" is that you're really asking for a plug "pigtail", not a power cord. And that's fine. Something "that short" isn't really going to need or benefit from shielding, vibration resistance, fancy alloy or silver conductors, etc. All it requires is big enough conductors to transfer the power required by the amp, and decent plugs for a good connection. If you write Chris and expain what you want to do, I'm sure he could create something appropriate for very little money.
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Thanks Neil, I ordered a two footer from him. Flavor 2 on Chris's recommendation with Gold Furutechs on both ends. Can't beat the price. In my rig the distance that is most important is the distance from the Audio Magic to the source and pre. Therefore, Harmonix Studio Master. Power cord form dedicated outlet to power conditioner (in my rig) does not require a mega $$ power cord. This has been knocked around, on the 'gon, a couple of threads or two, or three...