Power cord

[polkatese]

Guys,
this is a subject that I've been puzzled...I've been reading about the suggestion to replace factory supplied power cord on gears to improve the sound. The part that I don't get it was how can it makes a difference? unless it is completely malfunctioning, the quality of the power source would tend to be more relevant than the means to deliver it (unlike speaker cables and interconnects), thoughts? thanks.....polkarama

[RuSsMaN]

Well after you upgrade your power cord, don't forget to upgrade the wall receptacle too.

I'm on the fence on the power cord/receptacle upgrade, simply due to lack of experience with such upgrades. It does however lean toward the audio 'voodoo and doodoo' section for me.

Cheers,
Russ

[brettw22]

If you wanna just buy into it as everyone would like for you to........

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=32833&item=1947371173

Personally, I think that having a dedicated circuit running the pieces on your rack would be a better way to go than to spend the above money on a stupid lil cable. I think that there are better cables than the el cheapos, but NEVER will i spend several hundred dollars on a power cord............

[schumach]

I made my own power cords and it made a noticable difference on my system. I replaced the cord on my DVD player and the sound and picture quality improved. The DVD player had a 20% red push originally. After I replaced the power cord the push dropped to 5%. I can say I was skeptical at first, but I figured if it did not make a difference I was only out $20. Now I can say it was some of the best $20 I have spent on my system. I have made a few of these for others and they have also seen the difference, but you are the one in the end that needs to decide if it is worth it and also makes a difference. Good luck.

[polkatese]

Russ and Brett,
thanks for the info and I agree with you, skepticism is how I approach the subject....and there is no way I am going to spend $295 for a power cord :D

Schumach,
for entertaining my curiosity on this, I have no problem spending $20. The one question I have, what did you do? or perhaps, how did you come around to make one? did you use higher quality/heavier gauge of electrical cord? I am willing to test drive your cable if you do sell them....:cool:

[wangotango68]

I think that is one of the biggest myths in audio today. how come my sansui au-717 has a little power cord like you find on a lamp or small applience. specs: min.rms,both channels driven,from 20to 20,000 with no more then 0.015% total harmonic distortion. not worth the extra money to me.

scott:cool:

[gidrah]

I've been contemplating this one for my CDR as it has a removable plug. If it works well I will do another for my Dynaco amp. It doesn't have the removable plug but is pretty frickin' old. I'd be hesitant to work on any of my newer stuff.

http://www.tnt-audio.com/clinica/merlino.html

[schumach]

Here are some links that will help you make it yourself. The first is at AVS forum the second is what it should look like.

http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=126177

http://www.geocities.com/jaydmdigital/diy.html

You can do a search on the AVS forum looking up Maher and find links to other DIY projects that will help.

You find small power cords on equipment, because it cost money to make and ship. The manufactures only meat the guidelines required for the power cord. Most power cords are not going to have a ground and any noise is going want to go the least resistant path, which without a ground is going to be through your equipment. This means more noise and more ware and tear on the equipment. Take a dimmer switch on a fan. You can hear the hum via the speakers on a sound system (assuming they are on the same circuit). Connect a ground to the switch and the fan, the hum will go away (assuming the circuit at the box has been grounded correctly). Also bigger wire means less resistance, which means less heat. Heat will cause increase EMI and other noise on the line.

The twist in the wire work the same way as a CAT5 cable for networking. The tigher the twist, the cleaner the signal.

Good luck.

[brettw22]

Schumach......

You don't need any sort of protective shielding or jacket on the twist? I'd be pretty hesitant to just leave braided cable out like that and all exposed. Personally, i'd want some sort of shielding, but that's just me.....The braids look cute, but if the goal is a tight strand, then do this:

The best way that I've seen a strand done, that an electrician had done on a job site that I was working at was to take the 3 individual wires and cut equal lengths(make them longer than you need since it's gonna shrink down) . Tie, or secure, those lengths to something secure. Go to the other end of those cables and take the 3 ends and basically screw them into where a bit would go into your drill. Start it up and the thing will tignten completely solid and you won't have to worry about it unraveling. One BIG key to this is to keep the cables tight and stand back. Don't step forward in anticipation of the twist getting tighter and shortening up on ya. As it tightens up and pulls you closer, THEN get closer. If you are too close it'll get caught up in a knotty twist and won't be as tight. I watched an electrician make a 30 foot run of cable in about 30 seconds. I can't imagine trying to sit and hand braid a power cord just so that it looks pretty........my god. Only bad thing about that that I can see is that it'll make a fairly rigid cable.

Anyway, just a few thoughts........

[schumach]

Here is the PDF on how to make the power cord. The EIC connector is not needed if you plan go directly to the internal board.

brettw22 it sounds like you are twisting the wire. Braiding will intertwine the two grounds.

[brettw22]

Originally posted by schumach
Braiding will intertwine the two grounds.

What's the benefit of intertwining the two grounds? If you stick all 4 cables in a drill and twist them up, won't you be getting the same result?

[schumach]

Twisting keeps the wires in the same order, braiding moves the inner wires to the outside and the outside to the inside shielding the common and neutral with a separate ground. Doing this will change the characteristics of the signaling being emitted.

[brettw22]

I still don't see why if you were to use my twisting method you'd be losing anything over sitting there braiding one by hand..... You'd still be getting the grounds and other cables moved around each other...........right?

[schumach]

With a twist the ground wires wrap around the same common or neutral wire. With a braid the grounds alternate between the common and neutral. I hope I explained that clearly.

[brettw22]

Ok.......I get how you explained it......If braiding is such a superior way of making a power cord, how come all sorts of companies haven't come up with somethin like that on their own (or have they)?

Also, are you just supposed to leave the cable exposed like that or can you get some sort of wrapping around the braid? From a safety standpoint, I would think that it'd be a good idea to not just leave it exposed like that.

[schumach]

The wire has a shield around it. If you are thinking of it being like Romex (house wiring) it is not needed, this is only used to meet codes for wires in the wall and to keep the wire together. If you want it to look better you can purchase the black plastic coil wrapping from the hardware store, that is what I did.

[polkatese]

Schumach and Brett,
thanks for the discussions and information, any chance you could post a picture of what your cable looks like? thanks...

[schumach]

In one of my post there is a link to a picture of one that has been built, but here it is again.

http://www.geocities.com/jaydmdigital/diy.html

On a side note I have also used this design is making power outlets for the equipment to plug into. I have made over a dozen of them and every person that has one has notice a difference in sound (this is without modifing any of the power cords).

What I did:
At the end of the power cord I used a good quality outlet and metal box. You can make it with two or four outlets, but if you use four outlets remember to braid the wire between outlets.


Please note: this is not a link to my page, but of a member from AVS forum.

[gidrah]

Here's another braided design. I got some CAT5e for X-mas and will be doing some speaker cables when I can.

http://www.tnt-audio.com/clinica/ttse.html

[madmax]

I thought power cords were voodoo until I tried one. I bought a tube power amp from a guy and ended up talking him out of a $400 power cable he was selling on another auction which he used to use on the power amp I won. I was just in a mood and figured it looked cool and for $75, well, as I said, at the time I was just in a mood so I bought it. I used it for a while and at some point I plugged in a standard cable and noticed the sound just sounded dull. That is when I started playing with it. Sure enough, this cable added a lot of excitement to the sound. Since then I have made a few cables from parts at www.partsexpress.com and have been fairly impressed with them. I just got my Pioneer elite DV-47Ai DVD/SACD/DVD-Audio player. The cord on the thing is VERY impressive. Someone other than me seems to think it is important. I agree with the wall plug idea and if you go a step further you always end up with a cheap connection somewhere. I use a power conditioner and everything on the output side of the conditional definatly makes a difference. I can hear a difference with the tube stuff for sure but I have never played with SS equipment concerning power connectors. I have to wonder if it would make as noticeable of a difference because there seems to be a higher noise floor on the SS stuff. Not a hiss or any thing but more of a dynamic noise that changes with the signal which probably masks most of the improvement. I think I am on the audio fringes here but I've heard the differences and at the least, there are differences.
madmax

[rlw]

Powercords are audio black magic that works. Depending on your system, you might notice a large change or no change.

FWIW, I've tried a variety of DIY cords, and never heard any appreciable difference. I have had excellent results with TG Audio Power Cords and Audience PowerChords.

However, take my views with a grain of salt, as I am a dealer for these products.

[TroyD]

Oh JEEZE, another professional. ;)

Sorry, rlw, I couldn't help myself.

BDT

[polkatese]

thanks guys!

Gidrah, the link that you gave is interesting, the second picture of the braided cord looks great (can't you tell that I am easily impressed with great looking accessories?)
Do you guys agree that, if the cord will make a difference, then it should be matched with the gear's type of power requirements? for instance, for the power amp, the characteristics of the cables should be such that it promotes its ability to deliver high currents (such as thick 12 gauge cables, braided or not) more so than eliminating noise (provided that it is connected to a power conditioner) or did I miss the point? or does it even matter?

[madmax]

I used large guage cable but since I don't know where the improvement came from I cannot offer advice other than the guage must handle the given power the unit requires. I would assume a larger guage gives you a larger outside surface area (where all the electrons move) which would be better?
madmax

[mantis]

I haven't tried out swapping out power cords to see if there is in fact a audio difference.I'd like to give it a try.
I talked to the Monstercable rep not to long ago and he told me about the Monstercable replacement powercords coming.They might be out now,I haven't been in the store in a awhile.
Back when I worked at Soundex,alot of guys where swapping there cords for Transparents,they also claimed a big overall sound quality improvement.
I think when we get in the Monster powercords,I'm gonna give it a run and see.Interesting to say the least.Why not.

[polkatese]

PowerLine® 300, 8ft High Performance Power Cable

For high-performance hookup of high-powered audio and video components.
Multi-bundled wire technology with large gauge conductors for maximum current transfer.
Long 8 foot length provides greater flexibility for longer installations.
24k gold contacts for maximum conductivity.
Dual 100% mylar and 95% copper braid shielding for maximum EMI and RFI rejection.


MSRP: $99 available Feb 2003

[polkatese]

or its sibling for $49

[mantis]

Thanks brother,
I'll keep an eye out for them, try them out and post back.

[rlw]

Originally posted by TroyD
Oh JEEZE, another professional. ;)

Sorry, rlw, I couldn't help myself.

BDT

Nothing to apologize for: I'll always freely admit that I'm just a tool with a real little weenie.

Geez, maybe I should change my sig line to show that I'm a tool, in keeping with the image of a professional?

[TroyD]

heh, heh, heh.....

I do have a question about this though. OK, let's say you buy a new, expensive power cord, aren't you still somewhat hampered by the cheapie 99 cent outlet and non-dedicated circuit you are plugging in to?

Really, I'm not being a smartass, just asking as little as I know about audio, I know less about electricity.

BDT

[RuSsMaN]

I say skip it all, remove the outlet from the wall, and solder the in-wall wire directly to your gear (amp, power conditioner, etc).

Troy, you can buy 'upgraded' outlets. Some are referred to as 'hospital grade'.

Cheers,
Russ

[rlw]

Yes, you are hampered by everything else in the chain: remember, I think you're wasting money to upgrade any cables, whether speaker, IC, or power, until you have dedicated circuits.

Outlets can certainly make a difference: think in terms of good contact area, no slippage, etc - maximizing the transfer of electrons.

As far as direct soldering, that's great, until your house burns down, and the inspector determines that your outlets weren't wired to code, and you get to buy a new house out of pocket.

[schumach]

I would agree with the outlet and dedicated circuit. I have put in a 20amp circuit with 10-gauge wire to an insulated outlet (hospital grade). That alone, got rid of any noises emitted from appliances.

I believe it was rlw that mentioned that he has not used a DIY power cord that has made a difference. At some point these high-end power cords that are made were DIY power cords. Maybe not published, but somebody made them for others to test and decided they were good enough to market. Just a thought.

[HBombToo]

OK... I'll jump in here and then get slammed. ;)

Clean power is very important IMO but I see another marketing ploy here.

The "Plug and Wire" on the component was selected by the manufacturer to ensure it could handle the required load as per code. If the wire could not handle the load then there would be a fire and some really large insurance claims would be filed as a result of negligence.

Providing clean power on dedicated lines is a great idea because it provides dedicated breakers for protecting the electronics from lightning but I fail to understand how it can provide sonic benifits.

I have been deploying very expensive electronics for over 15 years now and we run the standard 12 guage electrical without any problems. If I proposed to the Senior staff that we should engineer our systems with esoteric products that the benefits could never be quantified... I would be LAUGHED out of the presentation.

If your power provider has problems or the wiring in your dwelling is bad then those are the issues that should be addressed. If so then please "Call a registered Electrician", for your own safety.

HBomb

[madmax]

At the minimum you loose the refrigerator noises (sometimes) and your lights stop flashing. One thing that amazes me is playing with X10 devices. They send their signal over the power lines. Often times they don't work if you get on another circuit. Whay does going through a breaker break this transmission from one circuit to another? They are all originating from the same input, right?
madmax

[HBombToo]

Originally posted by madmax001
At the minimum you loose the refrigerator noises (sometimes) and your lights stop flashing.
madmax

Agreed if there is a bad ground or there are too many outlets on the run this will cause problems.

QUOTE][i]
One thing that amazes me is playing with X10 devices. They send their signal over the power lines. Often times they don't work if you get on another circuit. Whay does going through a breaker break this transmission from one circuit to another? They are all originating from the same input, right?
[/B][/QUOTE]

This is a very interesting subject and now your getting into actual transmission line theory. Because the messaging is high data rate TTL, there are limits on the length of the run and reflections that must be considered. Without getting into a lot of messy uwave engineering lets just say that the reflections are 180 degrees out from the input and whatever is remaining from the incident signal after line losses the reflected energy must be subtracted out. After long line losses and reflected energies are accounted for the signal typically has less energy than the digital receiver can decode and hence the problem.

For every outlet and every breaker there are very small changes in impedance which cause these reflections. This is an issue for higher frequency messageing but for a 60hz power transfer it is almost unmeasurable unless there is a serious issue.

Hope this helps

HBomb

[madmax]

I guess there are the two phases as well. I just thought of that. I wonder if under one phase you put all your audio circuits and under the other phase you put the other household items if there would be any difference?
madmax

[HBombToo]

You would not want a large imbalance across the 2 phases. It would be more important to ensure a good balance across the 2.

I forgot to add in the 2 phases regarding the x10 box. This will definetly break the path if that was where the signal path was. I was thinking that the messaging is on the ground and not the power side... if I had to engineer it I would rather use the ground for the signal path but I don't own any of these devices and can't say. What if you connected the Box with an extension cord without the gound? would you break the signal path or does it still work??

I'm very curious about this.

HBomb

[madmax]

Many of the modules do not have a grounded input. Just the two blades. Maybe the ground would be too massive for the transmission?
madmax

X10 stuff is pretty cool. Check out www.x10.com
They have just about everything.

[HBombToo]

Originally posted by madmax001

X10 stuff is pretty cool. Check out www.x10.com
They have just about everything.

What equipment do you have that connects over the house wiring?

Thanks
HBomb

[madmax]

Recently I bought quite a few in wall outlets and a few RF video cameras. So far I have only played with the stuff but it is pretty cool. They have an rf remote which transmits to a receiver which plugs in the wall. Also, there are several programs out there which uses an rs-232 input device that allows you to set up macro's. So pretty much you could sit down on the couch, hit one button on the remote and it will turn on all the equipment through an IR device (have not got that yet), set all the lights, close the drapes, set your house alarm, water your dog or start the popcorn popper, whatever you can come up with. With little motion detectors, you could have someone walk up the front steps and cause the front lights to come up, volume on the stereo go down and turn on the camera and show it on your video screen. Imagination is about the only limit. As I say, I am still in the playing stage but it definately has a big potential.
madmax

[brettw22]

Originally posted by madmax001
Imagination is about the only limit.

And the almighty Franklins.....................

[polkatese]

amen to that, Brett.....thank you all for the great feedbacks, I learned a lot on this topic and will ponder some more, dedicated outlet seems to be the starting point, followed by a MC 3600 /5000 power conditioner, and then moving into the gears' power cords....by then, who knows, I might be able to afford thiel et. al. ...;)

[madmax]

Originally posted by brettw22


And the almighty Franklins.....................
You would be surprised how few!
madmax

[rlw]

Originally posted by HBombToo
OK... I'll jump in here and then get slammed. ;)

Clean power is very important IMO but I see another marketing ploy here.



Only too happy to oblige - but remember, it's all in fun :lol:

While you might "see" something, I follow the rule that audio is about trusting your ears. My ears tell me that I hear enough of a difference with power cords to justify the investment.

The "Plug and Wire" on the component was selected by the manufacturer to ensure it could handle the required load as per code. If the wire could not handle the load then there would be a fire and some really large insurance claims would be filed as a result of negligence.

The power cord, and everything else about the component, was also picked b/c of a product price-point. That price point typically does not include a good power cord.


Providing clean power on dedicated lines is a great idea because it provides dedicated breakers for protecting the electronics from lightning but I fail to understand how it can provide sonic benifits.

Breakers do NOT provide protection from lightning. A tripped breaker still has 1 phase connected, which is all it takes: lightning will travel through that 1 phase, as it seeks the shortest path to ground. To guarantee the safety of your gear in a lightning storm, YOU MUST UNPLUG IT FROM THE WALL [or find another way to disconnect both phases and the ground].

Dedicated circuits provide sonic benefits by providing enough current with a lower noise floor.

I have been deploying very expensive electronics for over 15 years now and we run the standard 12 guage electrical without any problems. If I proposed to the Senior staff that we should engineer our systems with esoteric products that the benefits could never be quantified... I would be LAUGHED out of the presentation.

So what does this have to do with audio, and improving the sound of a system? I've been programming computers for 20 years now, and I still run the standard power cords on PC's; minis and mainframes do get special power cords to meet current capacity demands. This has nothing to do with audio either.

As far as quantifiable results: I can hear the difference. That's the only quantifiable result that matters when I sit down and listen to the music.

If your power provider has problems or the wiring in your dwelling is bad then those are the issues that should be addressed. If so then please "Call a registered Electrician", for your own safety.

HBomb

Now that makes sense. Still has nothing to do with audio, though. :D

[goingganzo]

i have a surge protector/power condishoner and that is good enough for me

[weavercr]

Troy those are the expensive ones. Mine cost 19 cents at Home Depot. I however have a dedicate power line run for the HT and 2CH rig. 12 gage.

RLW 115 volt power is one phase power. 1 hot and 1 netural. If the breaker trips the netural / ground is still connected to the equipment. You are correct that breakers wont protect from lightning but it not because of the neutral wire it the fact that the breakers are too slow in reacting to the lightning transient.

[rlw]

Originally posted by weavercr
Troy those are the expensive ones. Mine cost 19 cents at Home Depot. I however have a dedicate power line run for the HT and 2CH rig. 12 gage.

RLW 115 volt power is one phase power. 1 hot and 1 netural. If the breaker trips the netural / ground is still connected to the equipment. You are correct that breakers wont protect from lightning but it not because of the neutral wire it the fact that the breakers are too slow in reacting to the lightning transient.

Hey, whaddya want for 2AM?

You're correct - 115 is single phase, but each leg can be balanced wrt load.

I do take issue with the "speed" of the breaker. If the "neutral" side is still connected to ground, that's a viable path for the lighting to seek ground - and that can be right through your equipment.

[polkatese]

Another great looking power cord from AQ nrg-2 for $119...looks great, but, can I tell the difference? :p

[madmax]

I find the tube stuff almost always presents a difference but the SS stuff seems to be masked somehow.
madmax

[polkatese]

madmax,
I've been reading a lot about power cords, and actually quite surprise that there are so many brands out there....there is a site that allows folks to demo the cords at home for 2 weeks. Anywhoo, since I am not into tubes (yet), if you have to take a quantifiable swag on the degree of "sonic quality improvement" of SS gears, by replacing its power cord, given a relatively brand new house (2 years old with electrical up to code from respectable builder, and living in a state that has codes for everything; currently no humming noise from emf/rf at all), what would be your take? thanks.....


"in pursuit of sonic excellence without breaking the bank....." :p

[gidrah]

The ultimate in cheap upgrades would be to go to a computer show (expo, flea market type thing) and pick up some used monitor power cables. These are usually pretty thick and have the ferrite rings.

I've already talked to my pseudo-electrician about running dedicated circuits in what will be the sound-room in my new house. I'll buy the materials and let her put them in.

[polkatese]

Gidrah,
that would be too easy...I've got several of those cables, I think....but isn't it serves a different purpose? at least, just by reading the spec on those oem audiophile power cords, or perhaps it says the same yada yada that the monitor manufacturers never bother to brag about??? thanks and let's see. magic eight ball says you are on your third coronas tonight..right? happy new year, bud!

[gidrah]

Originally posted by polkatese
Gidrah,
magic eight ball says you are on your third coronas tonight..right? happy new year, bud!

The magic eight ball underestimates my needs. I drank 3 beers while the ball was in flight.

Sure, it may not be the best solution, but considering the thickness, possible shielding, & ferrite blocks to stop RFI, I wish I would've thought of this sooner.

At $2-$3 a pop you won't get the audiophile magi doing a magic dance or counting the oxygen purity, but it seems like a viable alternative.


Damn I'm happy. This has the potential to be one of my best replies yet. I'm sure somebody that knows more will come along and shoot me down, but I've gotta just rave un2 for the moment.

[rlw]

Originally posted by gidrah


The magic eight ball underestimates my needs. I drank 3 beers while the ball was in flight.

Sure, it may not be the best solution, but considering the thickness, possible shielding, & ferrite blocks to stop RFI, I wish I would've thought of this sooner.

At $2-$3 a pop you won't get the audiophile magi doing a magic dance or counting the oxygen purity, but it seems like a viable alternative.


Damn I'm happy. This has the potential to be one of my best replies yet. I'm sure somebody that knows more will come along and shoot me down, but I've gotta just rave un2 for the moment.


I'm not sure how anybody can shoot you down - what you're suggesting is the soul of this hobby, playing around with new ideas to get better sound.

Good luck, and let us know how it turns out for you.

[mantis]

the soul of this hobby.........better sound.......I love it.Playing around with new Ideas is what I live for.When we get in the Monstercable replacement powercords,I'll be sure to buy first.Hell if it yields better sounds,I'm totally game.If it does nothing,they will go back......we will see......I mean hear.Stay tuned!!!!!!

[madmax]

Sorry I didn't get back sooner. I'd say if you could try the cord for 2 weeks it would be worth a try. Make sure you know a particular disc inside out and do a good comparison between the original and replacement cords. Try it several different times too, don't be in a hurry. Send it back if you don't hear a difference.
madmax

[HBombToo]

I really figured I'd be beat about the Head, neck and chest over this one... It must be the Holiday chear.;)

In all seriousness though, the only piece of gear I have that does not have a removeable high end power cord is my h/k 520.

With that said I like the fact that a lot of my stuff is a little higher quality, remember this is a hobbie, but I don't think it is absolutely necessary for an enjoyable listening experience.

HBomb

:D

[mantis]

HbombToo,
With that said I like the fact that a lot of my stuff is a little higher quality, remember this is a hobbie, but I don't think it is absolutely necessary for an enjoyable listening experience.
This will change from each persons perspective.I can't wait to try the powercord trick.

[weavercr]

I was not able to hear any significant differences
due to highly specialized power cords when I listened
exclusively to a Class A SS amp, other than using the
heaviest gauge to minimize voltage drop due to the cord,
and if the cord has shielding. The heaviest gauge commonly
avaialble for a pre-molded IEC type cord is 14 Ga. The
shielding available is usually a foil type shield (although some
have a copper braid), and this can help with RFI problems
sometimes.

Once I started listening to a Class AB tube amp, then I
noticed more of an effect with power cords.

It is easy to underestimate how much drop a typical 18 gauge
AC power cord will have on a power amp, and even how much it
might affect a preamp or CD player. Sheer heavy gauge AC
power cords will minimize any dynamic fluctuations and shielding
will help with localized RF or EMI interference problems.

By way of further explanation, I provide this copy of a post on
AC power cords I have made before:

AC Power Cord Effects

So, how in the world can a power cord make any difference,
if it is properly rated for the current draw, and is UL listed?
Like many questions about audio systems, this one seems very
logical and reasonable. Just use Ohm's Law to calculate the
current draw, and viola, we have the voltage drop, and we have
the cold hard facts, Yes?

No.

Like many overly simplistic answers, this one does not take into
account all the facts. Let's look at a hypothetical power amp to
start. Lets say it is a moderately high power design, and is rated
to draw about 8 amps from the wall at full rated power. That's
about 960 watts from the wall. We won't even get into side
issues of switching power supplies, which play total havoc
with the simple Ohm's Law approach, we will stick to linear
power supplies.

So if the AC cord is UL listed for 10 amps, it is likely an 18
gauge cord. Many 18 gauge power cords are rated for 10 amps
of current. How is this rating determined? By how hot the cord
gets while carrying the rated current, NOT how much voltage
drop there is.

In our hypothetical amplifier, the RMS voltage drop in the 6 foot
cord would be approx. 2/3 of a volt according to Ohm's Law.
This does not take into account the wall outlet contact, or the IEC
connectors if present, nor does it take into account any other
factors, just the resistance of the 18 gauge wires in the AC cord.

On the face of it, this seems quite harmless. How could two thirds of
a volt make any difference? Well, because the voltage drop is NOT
2/3 of a volt! Has Ohm's Law been repealed? Are engineers all
insane?

No, just an overly simplified analysis that failed to take into account
ALL the factors. So what could possibly make that much difference.
Well, for one, it would help to know that linear power supplies
refresh their DC reservior from the AC line in bursts of current,
current peaks that are in time with the peaks of the AC line. That
is when the filter capacitors are refilled, when the AC line voltage
its it's peak value, and the output from the secondary reaches a
level above that which the PS capacitors have been drained to.
Instead of a nice steady drain of 8 amps, we have current peaks that
last only for a brief moment, and the 8 amps is an RMS amount.

What this means is that because the current is being drawn only for
a fraction of the AC voltage cycle, or for about 1 thousandth of a
second (one half cycle lasts for 0.0083 seconds). The peak currents
can easily reach ten times the RMS value. What is the voltage drop
for 80 amps? At this point, the resistance of the AC plug contacts,
and even the bond inside the cord between the plugs and the
internal wires become a significant factor. It is not hard for the voltage
drop to reach 5 volts or more. The AC line peaks never reach the full
value, because the line cord has lost some of it.
Power amps depend on receiving the full measure of AC line for
their full rated power, so such a drop will reduce the actual output
power in a seemingly disproportionate amount. A 200 W amp may
be reduced to 170 watts before clipping.

The above (still simplified) analysis assumes a steady signal, and a
steady current draw. Musical dynamics make it a much less
consistent thing, and the dynamic demands will cause dynamic
perturbations.

This is not the only effect on the power amp. These current peaks
can easily cause AC line distortion, and the heavy current draw can
generate harmonics on the line, the hash from the rectifier diodes
can increase, a whole series of events occurs that are not
immediately obvious just by thinking of the amp as a simple resistor
and using Ohm's law.

Most house wiring is either 12 gauge or 14 gauge, while many OEM
cords are 18 or at best, 16 gauge. Most OEMcords do not have
shielding or any provision for reducing radiated EM fields, do not
have premium AC outlet plugs or premium IEC plugs for better
electrical contact at these junctions.

So what happens with a bigger power cord? Replace that 18 gauge
cord with a 14 gauge cord, and the voltage drop will go down by a
factor of about 2 and a half.

Include shielding in that cord, and the possiblity of radiated EMI/RFI
goes down compared to an unshielded cord.
Shielding and radiated EM fields might not seem relevant since the
house wiring has neither advantage. However, the house wiring is
not laying right next to the other component's AC line cords, or right
next to the line level or speaker interconnects. Reduced levels of
induced RFI and radiated EMI/hum fields would not hurt SOTA
sound reproduction.

Since the AC power cord is usually laying right in there with all the
other AC cords, and probably the speaker cables, and the
interconnects (some people even bundle them all together for
neatness, OUCH!), it is quite possible that a premium AC cord
will help reduce interference in the system, and raise the amount
of power available before clipping, and smooth any AC line
distortions, etc.

This is all without even going into secondary effects, or other
more esoteric aspects. Just a more nearly correct way of
applying Ohm's Law to the real situation. Add in ferrite filters,
built-in filter components, shielding effects, and the esoteric aspects,
and it should be obvious that AC cords are not at all simple, nor are
they a no-brainer.

There is the issue of resonant situations. Certain power cords and
power supply transformer primaries might tend to resonate at RF or
high frequencies. This resonance might make RFI/EMI problems
worse, changing to a different cord will change the resonant
frequency, and change the RFI/EMI effects.

The plugs are not a trivial issue either, and may be more responsible
for sonic improvements than the other factors. Hubbel and other
premium plugs and sockets will increase contact area and pressure,
reducing contact resistance and other contact related problems.
It has been claimed that poor AC plug contact can cause micro-arcing,
with it's attendant hash being injected directly into the audio component.

It is not as simple as just simple wire resistance. The connection at
each end of the cord adds resistance, the wall outlet socket adds
resistance, etc.
For the raw wire, round trip:
12 gauge, approx. 6 feet = 0.0206 ohms
14 gauge, approx. 6 feet = 0.0328 ohms
standard AC power cord
18 gauge, approx. 6 feet = 0.0830 ohms

Measuring real AC power cords, I get around 0.128 ohms for an IEC
18 gauge power cord, and about 0.022 ohms for a 12 gauge IEC cord,
not including the AC wall socket connection.

Why is the 18 gauge resistance so much higher than just the wire
resistance? Ever tear one of those cheap cords apart? poorly crimped
or barely soldered connections are responsible for the bulk of the extra
resistance.

Preamps and CD players all have their special requirements:
CD players require shielding to help keep the digital hash that
back-feeds from the circuitry out of the rest of the equipment, preamps
need a nice steady voltage for minimum noise, and freedom from
RFI, etc.

Fancy AC power cord geometries might also reduce the inductance
of the 6-8 feet of line cord, raising the available voltages, but this
would be limited to the ratio between the length of the power cord vs.
the wall run. Such geometries often reduce the radiated energy,
and aid shielding of the cord.

Some power cords might have a built-in filtering action, like the
water jacketed ones, that have the conductors and insulation
surrounded by a conductive fluid. This fluid might short out and
reduce/damp any EM fields the cord would conduct to the component
besides the 60 Hz AC power signal.

It also helps to keep in mind that we are not supplying a Sears rack
system, that any system which aspires toward the SOTA is going to
be more sensitive to minute effects and minute improvements. How
much does a big fat shielded power cord help things? Probably
about as much as upgrading from an OEM interconnect or zip cord
speaker cable to some decent aftermarket cables, some systems
are more sensitive to AC cords, some are less sensitive to cords.

As always, the bottom line is: you have to listen for yourself, and see
if their is any benefit for you, on your system, with your listening habits.

Do AC cords have the potential to influence high end sound? Yes.
Does anyone who believes this also believe that high end cord
costs are justified? No.

Some of the cord/cable manufacturers get carried away with using
only the very finest materials and assembly techniques, carrying
over the technology and costs from their high end audio
interconnects and speaker cables.

Is this necessary? I don't know, I will not discount it out of hand.
Does it make the cords cost a lot? Yes.

Does this make them dishonest or imply that they are deliberately
trying bilk the customer? Not at all.

While AC cords made from certain models of speaker cable may
provide some extra benefit, I have not been able to hear distinct
improvements when comparing them to just plain heavy gauge and
shielded cords when listening to a Class A SS amp. When I
started listening to a Class AB tube amp, then power cord
differences became more apparent.
Results in your system may vary. I have not
tried Belden 89259 in the cross-connected speaker cable hook-
up as an AC cord, but plan to sometime.

Below, I have listed information on DIY heavy-duty AC cords, both
pre-molded and raw wire.

Commercial numbers for these types of cords are:

PREMOLDED
****************
Belden
17604 6 ft. (Around $10)
17605 10 ft.

Still a big heavy cord, but 16 Ga. (and still better than
most OEM cords) are:

17602/3

17608/9 (right angle into gear)

copied from a post by Jon Risch

[polkatese]

weavercr,
thank you for the great article, appreciated very much....

[rlw]

...is an oversight on your part.


Originally posted by weavercr

By way of further explanation, I provide this copy of a post on
AC power cords I have made before:




Unless you are Jon Risch, you really should make sure to credit him. Jon has put a lot of effort into his website - he's a good guy and deserves the recognition.

If you are Jon R., well, hi Jon, long time no talk.


The Real Deal (http://www.geocities.com/jonrisch/ac-cords.htm)

[gidrah]

:eek:

Coincidence.

[madmax]

Wow,
Three pages on power cords! I'm surprised. All parts of the system are important. I'm happy to see consideration going to some of the less thought of parts. I'm wondering if power cords effect tubes more because of the higher supply voltages? SS equipment normally have +/- supplies of 35 to 70 volts. Tube equipment has -400 volt supplies for the grids and some other voltages. Just wondering if anyone has ideas about this?
madmax

[RuSsMaN]

//Side note to everyone else EXCEPT MM//

Anyone else think he's either

A. Full of shit, or
B. Has the ears of a bat?

This guy isn't an Audiophile, he's a tweak-o-phile through and through.

Just hackin' on ya Chuck. ;)

Cheers,
Rooster

[RuSsMaN]

Chuck, I hope you took that at face value, I'm jealous, if nothing more. Much respect amigo.

Cheers,
Rooster

[mantis]

Russ,
Ever consider EXPERIENCE????O I forgot THEY didn't want you.

You talk more TRASH then anyone I ever read.Looser.Ever consider adding to the eff in thead instead of cracking asshole jokes?You are a Clown.

[RuSsMaN]

...edited for content...

[mantis]

I don't have hardly any experience with powercords.But I don't go around saying whatever,lets skip over it,can we move on,blah,blah,blah.
I'd like to learn more about powercords and if they make an audio difference.Like the rest of the people on this thead digging into it.
Not everyone on this forum feels like you do Russ.Some people like to read what I write/type.Even if I do misspell words.

Russ I really think you need to go relax.Your so tense these days.

[rlw]

Click the button marked "profile". Click the menu item "Edit Ignore List". Click update.


Ahhhh.

There, that's better.

[rlw]

Originally posted by RuSsMaN
//Side note to everyone else EXCEPT MM//

Anyone else think he's either

A. Full of shit, or
B. Has the ears of a bat?

This guy isn't an Audiophile, he's a tweak-o-phile through and through.

Just hackin' on ya Chuck. ;)

Cheers,
Rooster


I'd probably go with (B) - Jon's been active in the industry for probably 30 years, and is currently designing product for Peavey. I'm guessing that his hearing is pretty good.

Is he a tweak-o-phile? I think what he does is great: he comes up with DIY stuff that offers an alternative to commercially available products. Remember, even Polk started as a couple of guys working out of their garage to make better sound - IMO, that's the soul of this industry.

Of course, keep in mind that I've been known to hang speaker cables from the ceiling, as they certainly sound better when they don't touch the floor.

:D

[HBombToo]

Originally posted by rlw


Of course, keep in mind that I've been known to hang speaker cables from the ceiling, as they certainly sound better when they don't touch the floor.

:D

I don't think I could get that 1 past the almighty WAF! ;)

[madmax]

I haven't tried hanging them from the ceiling yet but it sounds reasonable. I've heard that once cables are burned in, if they are moved around and vibrated that they will require another burn in. Read that somewhere.
madmax

[TonyPTX]

Originally posted by madmax001
Many of the modules do not have a grounded input. Just the two blades. Maybe the ground would be too massive for the transmission?

From a safety standpoint, it's not a necessity to have a dedicated ground wire within your 2 wire/blade plug. That's why if you look at most of the 2 pronged plugs, one is wider than the other to ensure that you have correctly inserted the plug into the recepticle. The wide blade is usually the "white" or neutral line (if memory serves me right). "Black" is usually hot. If you follow your "white" wire back to your breaker, you'll just noticed that all of them terminate on a common block. That block is then "grounded" with the common "ground" block, thus the white wire can be seen as a "ground" however to truely be labeled as a "ground" it must be on a dedicated circuit, thus the bare wire that is usually bundled in a 3 wire romex sheath. Most company's know that this is "official" NEC certifed wiring methods so the "white"/wide blade is usually internally grounded in the chasis of the AV equipment. Problem that comes to mind is whether or not the electrician wired your wall recepticles properly. (ie white to the white side and black to the black side).

[gidrah]

Originally posted by madmax001
I've heard that once cables are burned in, if they are moved around and vibrated that they will require another burn in. Read that somewhere.
madmax

I've read that also. Can't say I've noticed it or believe it's that big of an issue.

[HBombToo]

Originally posted by mantis
I don't have hardly any experience with powercords. I'd like to learn more about powercords and if they make an audio difference.

Perfect time for ya is right now during your construction. I'd start with a good ground ring for your dedicated HT. I have a friend who I consider and "EXPERT" on grounding and follows our Forum and would be happy to help you.

Also as Russ and a few others have mentioned you should consider Hospital grade outlets and make sure you run all 12 guage power lines.

This should really accent your already owned power conditioner.

Just my 2c

HBomb

[polkatese]

Guys,
to continue on the thread that I started off a while ago, I went ahead and order Signal Cable MagicPower cord from Frank (at $59 for 3ft, I can afford it and not loose sleep over the investment if it produces no difference). So, I got it a couple of days ago and hook it up. Remember that it hasn't go any burn in period (i.e. an immaculate virgin power cord :p ). Build quality is very good, thick, and robust. The cable is also pretty stiff (no Viagra involved..). Check out the signal cable web site for specification, if you are interested (www.signalcable.com)

Off the bat, once I power on the rotel 1065, I noticed a profound improvement of bass and mid immediately. For the source I use the philips SACD-1000 and a redbook cd that I am very familiar with (Joe Sample - Sample This). I will spend more time listening to the system and let you know, but, at this point, I will tell you one thing, you can TELL the difference, having the stock power cord replaced with a different power cord of different build quality (or perhaps, lower gauges)

[PolkThug]

Well after you upgrade your power cord, don't forget to upgrade the wall receptacle too.

I'm on the fence on the power cord/receptacle upgrade, simply due to lack of experience with such upgrades. It does however lean toward the audio 'voodoo and doodoo' section for me.

Cheers,
Russ

You should give them a try. ;)

[TN_Polk_Lover]

OH NO! Now we have 2 old power cord threads resurected from the dead!

Robert

[Deadof_knight]

HAHAHAAH upgrade the recptacle to a 100% pure copper OFC or buy the silver oxide model..... wait wait Im sure someone has some gold plated ones.. you also need to run stranded 4 gauge to your outlets and while your at it upgrade to the 50 amp plugs.......


Sorry having fun with this