Power Cord Shoot-Out: 22 Power Cords Reviewed

Power Cord Shoot-Out: 22 Power Cords Reviewed

Read marl of head-fi.org Power Cord Shoot-Out: 22 Power Cords Reviewed at http://www.head-fi.org/forums/showthread.php?p=2663648

Power Cord Shoot-Out: 22 Power Cords Reviewed

Guys, please read theaudiocritic.com before spending money on such things!!

Ravi

Here is the proper link: http://www.theaudiocritic.com/downloads/article_1.pdf

Cheers

The other side of The Audio Critic recommended here---
The Audio Critic started publishing somewhere in 1970 and went on for about 10 years with a good reputation and honest reviews and appraisals. Then the publisher unfortunately turned into a speaker manufacturer and the business bombed after a few years. The magazine was reincarnated (now it is only web publication) and its standards have gone down the drain, especially as if the publisher now wants to take on the entire audio world with venom and unreasonable and illogical conclusions. He now believes that except for speakers, all other components in the audio chain make no difference! His conclusions are that a $100 CD player vs a $10,000 player or a $500 amplifier vs $5,000 amplifier do not make any difference, and he is willing to prove these by ABC testing!! The biggest joke is that he considers digital sources superior to analogue ones!!!
So if you wish, welcome and try and follow The Audio Critic.
I wonder why with so much knowledge and information in websites now, people bring in such ideas.

> murali

Yeah I read the pdf, and it seemed a little extreme rejection of almost everything. He said tubes are not better then transistors etc etc ...

Thanks for the tip off.

Regards

In the audio critic articles, somethings might not be right, but that does not make everything they say as wrong. A lot of things that they say makes perfect sense.
I mean, come on, changing power cords to get a better audio performance, thats just plain ridiculous and gullible. Going by this logic, I should also change the power cords of my computer to get better audio video, change the power cords of the fridge to make beer chill faster, make table lamp give brighter light.

Just look at the power cables that are bringing power inside your house and the wiring in your house. Its probably costs like 5 bucks a meter. After this, even if you add a 500$ cable to carry current to your amp, it wont make a difference. Its just bullshit. How much ever you try to convince me that it makes a difference, it just wont cut. Principles of electrical engg, audio engg, physics, science, common sense, logic etc all dictate that its all bullshit and the guy who's selling you these power cords is conning you.

No offence to anyone, just my 2 paise.

Well..The internet is full of information very often conflicting...its your choice on whom you want to elevate to Guru status, whom as "another voice" and whom as an idiot !

Its a personal choice and each person may have his own opinion and result.

Regrading the Audio Critic he has his share of fans and detractors and not just from the audio manufacturers.

But in the end there are lot of people who feel there is a difference and many who dont.

for entry level equipment the difference may not be very obvious but just dismissing everything as Balderash will only hamper ones own learning in this hobby..the more open a mind you keep the more you will learn.

the points you have raised are logical

Jon Risch is a guy with a scientific bent who has experimented a lot with power. makes sense reading his site as he gives a logical view of the other side as well.

this is a hotly debated topic with a lot of arguments on both sides..suggest dont take a side just now go by the ears for the time being

but again there are quite a few Snake oil peddlers in the business as well..just becaus a cable is expensively priced does not make it good. but all powerchords are not alike !

The following is what Jon Risch published on this subject:

Quote:
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.

Ah the same old argument. Peter Aczel has a lot of valid points, especially in that classic "ten audio myths" article....and a few that don't make that much sense....but this "downfall" came about because of a controversy that was clearly engineered by his enemies including John Atkinson of Stereophile.....and yes, right now he is a bit too venomous, but don't discount everything he says......some of the points he makes are perfectly valid....someone mentioned tube amps....his points are spot on.....tube amps are less accurate than solid state amps.....and less "faithful" to the original recording.....people love their sound because the tubes add a colouration that adds warmth....by subduing the harsher aspects of the treble frequencies and emphasising the mids....but they are by no means dead-on accurate....the "coldness" that people complain about in solid-state amps is just the accuracy and lack of colouration....

it's like after drinking tap water regularly...if you drink water that has gone through an RO purifier.....you will say that the RO purifier has given it a taste.....the fact is that it is the tap water that had the taste....the RO purifier took it away to give you pure water.....but on a comparison, there seems to be a difference, and this is what people attribute as the "taste" of RO purified water...