Do I need a power cable - if so what brand?

While I believe that those who may have contrary opinions are sincere, and many among them are astute judges of sound quality, for whatever reason I believe that opinions that power cords can make a significant difference in sound quality are utterly mistaken. I assume in saying so that your contacts are clean, plugs and jacks make secure contact, and wire gauge is adequate (all of which can be assured with some contact cleaner and a $5 power cord).

With probably hundreds of feet of wiring inside and outside of the house to the power company's transformer on a nearby pole (that steps down 10kV or so to 115V), and miles of wiring on the other side of that transformer to the power sub-station, what difference will the construction of 6 feet or so of wiring from the ac outlet to your system make? And even if it does make a difference, by what mechanism would the use of exotic and expensive materials in the cord correlate with improved sound quality? Putting it another way, are the differences essentially happenstance, which would mean that a cheaper cord might be just as likely to outperform a ridiculously expensive cord as vice versa?

I should add, to put my comments in perspective, that I have two degrees in electrical engineering and several decades of experience as an electrical design engineer, and more than 25 years experience as a high-end audiophile (Levinson, SOTA, Grace, Grado, various tube and solid state amps, Pentagram speakers, etc.).

Regarding power line conditioners, I'd imagine that their effectiveness or lack thereof would be dependent on the design of the power supply sections of your preamp and amp, and on the quality of the ac coming into your house. Which would mean that trial and error is the only way to tell.

I can readily envision that in many homes dedicated lines for the stereo system may be helpful, notwithstanding my comments about power cords not making a difference. For instance, if other devices such as heaters or refrigerators are pulling large currents through lines in the house that are also supplying the stereo system, the system would see less voltage than if fed via dedicated wiring. The miles of wiring outside the house are typically much larger gauge than those within the walls, and are designed to support much larger currents without significant voltage drop. Also, dedicated lines could conceivably help isolate the system from rfi produced by those other devices.

In general, the better the design and quality of the power supply circuits within the system's electronic components, the less sensitive I would expect those components to be to dedicated vs. non-dedicated lines and ac line conditioning.

Dave (Dlcockrum) -- Let me answer your well phrased thoughts about my not validating my opinion via experimentation by drawing an analogy to the businesses you have successfully managed. You were no doubt required to frequently and almost continually make decisions as to what tasks should be given priority in allocating limited personnel, time, and financial resources. In so doing you used reasoned judgment that drew upon your experience and education, and upon analyses and thoughts that others may have presented to you.

Similarly, I choose to allocate my audio-related investments of time and money to where my judgment tells me it is most likely to be most productive. That is why I choose to not devote time and money to assessing the sound of power cords.

I cannot explain why many sincere and intelligent people believe that they hear significant differences between power cords. I do feel, though, that the marketing hype surrounding them is generally techno-babble that fails to provide a rational correlation between the cord design and the claimed sonic effects. Therefore, as I implied in my earlier post, if there indeed are effects, they are likely to be system-dependent, they are likely to be findable only through trial and error, and they are likely to have no signficant correlation with price.

Regards,
-- Al

Good! But in your most recent assessment of the power conditioner, did you compare the sound with everything connected through the conditioner to the sound with nothing connected through the conditioner? If not, and you had some things connected through the conditioner and other things connected directly, as I explained earlier your findings may be misleading and your setup is probably not optimum.

Regards,
-- Al

Dave -- Thanks for your response and your suggestion. I'll try to do that, perhaps in a couple of months because right now my pre-amp, amp, and phono cartridge are all in the process of changing, and obviously I want to become thoroughly familiar with the sound of the new components before trying to evaluate subtle cable differences.

Satiger -- I'm wondering if perhaps the reason the receiver sounded better through the conditioner was not the fact that it was connected through the conditioner per se, but the fact that it was then connected through the same path as all of the other components. I presume that the conditioner has some inductive as well as capacitive filtering in it. The inductors would be in series between the ac line and whatever components are plugged into the conditioner. But when you plug the receiver directly into the wall, with the other components plugged into the conditioner, the inductors create an isolation at high frequencies (probably much higher than audio frequencies) between the ac power and neutral going to the receiver, and the ac power and neutral going to everything else. It's hard to predict what sort of sonic effects that might lead to, but it seems conceivable to me that that could be the cause of the differences you heard.

I have always used a mundane but good quality power strip/surge suppressor to protect my system from lightning strikes, power surges, etc., with all components being plugged into it. Corresponding to the question you raise at the end of your last post, I'd welcome opinions from the others as to where a quality power cord would be likely to do the most good -- between each component (or at least the most critical ones) and the surge suppressor or conditioner, or between the suppressor/conditioner and the wall, or both.

Regards,
-- Al

Almarg, is it possible that a power cord can act like an antenna? Remember that we used to use wire inside a plastic covering to pick up radio signals for our tuner.

People do sometimes have problems with phono inputs picking up radio signals, due to the very high amplification that follows, the highish impedance levels, and the fact that those lines are directly in the signal path. In fact there are two threads presently ongoing here involving that kind of problem.

But it seems extremely unlikely that a similar situation would arise with a power cord. First, impedance to ground is low, which would tend to "short out" any rf that was being picked up. Second, there is no subsequent amplification. Third, there is no direct path between the ac input to a component and the signal path. Assuming the design is well done, the power supply section would include filter capacitors that have good performance at high frequencies (in addition to the large electrolytic "cans" that provide energy storage and ripple filtering but don't do much at high frequencies). And the amplifier stages themselves presumably all have "decoupling" capacitors that filter out high frequency garbage from the power going to those stages, right at the point of use.

Regards,
-- Al