After Market Power Cables - Gold or Snake Oil?

People who argue against the sonic benefits of powercords either, in my opinion, haven't tried them, or have equipment designed such that they don't make much difference (either because they don't resolve the information or are designed with spectacular power supplies: I gather this is true to some extent with certain brands of electronics such as Bryston). In my system, which includes Audio Research electronics and Transparent cabling, the differences between power cables and the improvements they can offer are both shocking (to me, a former skeptic) and instantly obvious to anyone. It's not subtle. Forget electronic logic on this one. Bumblebees can't fly either, according to aeronautics. The history of science is the recognition of clear phenomena, and trying to find a way to explain apparently anomalous conclusions after the fact.

Indeed, in medicine, particularly in Britain, there's a movement towards what's called "evidence-based medicine." When I naively suggested to a group of doctors at a party that I assumed all medicine was "evidence based" they could barely contain their laughter. Figure out what works first, they said, figure out why later... or maybe not at all (no one really understands even now why aspirin works, an analogy I've cited in these forums [fora?] before). Same here (if towards less serious ends).

Pure Note Sigma: I use to think all this talk about power cables made no sense. But, this relatively inexpensive cable transformed my $60K Krell/B&W system.

See my review under Pure Note and go to purenote.com

Try it!

Richard

I personally use cheap Cardas power cords ($79) only for mechanical superiority to computer grade power cords. I've
tried some $200+ power cords in the past. They appears to make a difference but it largely disappears with time or during a blind test. Have you ever wonder why your system sometimes sounds good but not other time even without any
change in your system? You must do reliable listening test to determine the difference. I am not so called audio objectivist since I do own audiophile brand name equipment and cables but PC is where I draw the line.

My advise, try it before buying it. Most systems will get a
modest improvement with a good quality power cable like
PS Audio Mini Lab, 10 awg shielded cable for around $150.00 . Unless you have very exotic or power hungry amps
you won't need an expensive power cord(>1K). Like others have said before you must start with dedicated lines, isolated ground preferred, and quality outlets. In the past
I have tried different power cords, on some brands of amps
(Krell) they did made a noticeable difference, on others like Linn the difference was very subtle, Linn do have great transformers, shielded in the case of the Klout amp.
I took one of my Klouts to an audio store to try one really
expensive power cord, the salesman gave a lecture on the big difference this cord will make with it's 8 awg wires, at
that point I removed the cover of the amp to show him that the amp was internally wired with 18 awg cable from the power connector to the transformer. I asked him why would I need a 8 awg power cord when the amp only draw 6.3 amps, he
had no anwser for my question. Anyhow the expensive cord didn't improve over the $150.00 one. So please be advised that I am not telling that you will not get an improvement,
all I am saying is that because someone says that he or she got a huge improvement in their gear it may not do the same on yours. Like I said, try them first, if you hear an improvement buy them. Select the brand you like and start with the cheapest model, you will find that you will reach
a point where the next model will not sound better than the
previous, the previous will be a good match to your system.

Amplifiers demand current from the power-line when the capacitors in their power-supplies become momentarily discharged due to high-current transients in the music signal. This discharge condition must be quickly recharged from the power-line, through the power-supply transformer, or a voltage sag will occur. Such voltage sags can cause audible distortion at the loudspeakers. If the power-line has significant series inductance in the path from the power panel to the amplifier, this can prevent the capacitor bank from recharging in time to prevent a voltage sag from occurring at the amplifier output transistors. With a low-inductance cable, the voltage drop across the cable will be insignificant during high-current transients, minimizing the voltage sag. This allows all of the current needed by the output transistors to be supplied when they need it, resulting in fast, dynamic response to transient signals.

What is important to understand is that typical rubber cords have many times the inductance of the ROMEX in the wall, so adding a rubber power cord is like extending the ROMEX from 20 feet to 30-40 feet. Here is a calculation based on actual measurements:

A typical 6-foot 14 AWG rubber cord and 25 feet of ROMEX has inductance of 7.2 uH and resistance of 235 mohms, ignoring the plug resistance effect. Therefore, the voltage drop at 20kHz will be I*(wL+R)= I*(.905+.235) = I*(1.14). With a 6-foot Magnum2 and 25 feet of ROMEX, the inductance is 5.9 uH and the total resistance is 147 mohms. This is an 18% reduction in inductance and a 37% reduction in resistance. The voltage drop for this combination will be I(wL+R) = I(.741+.147) = I(.888). So at a fixed dynamic current I, the voltage drop in the entire power feed at 20kHz is 22% smaller with a Magnum2 power cord. I would consider 22% to be significant. The reality is even more compelling. When you add in lower plug and receptacle resistance and the fact that the di/dt on the power cord will have spectra well above 20kHz with some amplifiers, the low-inductance cord makes an even bigger difference.