how can a line cord affect frequency response ?

Metro04: I was basing my comments on basic power supply engineering. I'll start a new thread on the bandwidth requirements of line cords shortly.

Dpac996: Actually, what you want to use in that experiment is not a differntial probe, but a current probe. This is a device you can clamp on the wire and monitor the current flow through the wire. Tektronix makes several of these types of probes; the basic one with a DC to 50 MHz bandwidth is fine. I plan on doing this in the lab this week, just to see the what the bandwidth is of some cheap basic line cords versus the more expensive ones. I'll post the results in a new thread.

Mrtennis and Tvad: Gee, a cable designer said it makes a difference, so therefore it does. But, he gives no explanation for the reason, no facts, no information based on his own experience in the lab, no experimental data, nothing other than his own opinion, which is what he uses to sell cable at 500 to 2000% markup. If he could sell lots of cable based on opinion, think what hde could do with solid data and facts! What is wrong with this picture? As I have stated numerous times in the past, I am happy to be proven wrong on my opinions, but please, someone show me something other than profitable based opinion that I am wrong.

To all, a general note: Please keep in mind that power supply performance is always improved by adding large inductors in series with the capacitor filters, not by removing inductance. So simply stating that "adding inductance is bad" is wrong. Yes, it can be bad, depending upon where you put it, but let's assume the power supply engineer knows what s/he is doing. After all, you must have some faith in their skills, as you bought their amplifier! Other than cost, and they are expensive, an inductive input L or capacitive input Pi filter, are impossible to beat for power supply filters.

Tvad: Gee, a cable designer said it makes a difference, so therefore it does. But, he gives no explanation for the reason, no facts, no information based on his own experience in the lab, no experimental data, nothing other than his own opinion, which is what he uses to sell cable at 500 to 2000% markup.

My opinion is that no designer is required to provide any information which is proprietary to his product. Not providing a technical explanation does not by default correlate to fraud. Coca Cola does not share its recipe for Coke, and yet few argue that people enjoy the beverage without having to know the formula.

If you want some technical discussion about the effects of resistance, inductance and capacitance on cables, you might take a look at this from Alpha-Core.

Also, many recognize the benefits of wire geometry and shielding to reduce EMI/RFI. Canare (and others) utilize a four conductor starquad array, which is explained here.

I realize this is a discussion of speaker wire, but the principles apply to other wires.

Finally, having read enough of Mrt's threads, it is clear to me that he does not ask a question to get a definitive answer as much as he asks the question to provoke heated discussion. He is a baiter in poor disguise. So be it. This debate over wire is a no win situation, as has been proven time and time again in a dozen or more threads on the topic of wire. Eventually entropy prevails, and the threads unwind into posts that convey frustration and anger.

This one will get there eventually, too.

In the meantime, if anyone cares to learn some science behind cable design, then take a look at the links above.

"Not providing a technical explanation does not by default correlate to fraud. Coca Cola does not share its recipe for Coke, and yet few argue that people enjoy the beverage without having to know the formula."

Coca Cola isn't marketing product based on performance/technical claims that can be verified by the end user. Food companies are not obligated to disclose trade flavor secrets. Two different comparisons.

All of your other audio "electronic" products must meet manufacturer's performance claims, or can be held liable for mis-representation or false advertising. Where is there ANY equivalence to this in audio related "tweaks"? Notice how "vitamin/health food" companies can no longer make health claims?

There should be some agreed upon (and regulated) standards within the industry, just like the rest of your "electronic" components.

OK, Metro04.

In the meantime, did you read the information presented in the links I provided. Does ANY of what is written on those pages provide anything valuable to you?

SpatialKing,
Sure that could work too. Do you plan to trigger on the ac-line frequency and run some test signals into a power amp, or do you have some other arrangement in mind. If you have a typical amp and speakers in your lab that would be best of course, to correlate the fluctuations in the musical signal to the changes in current as picked up by your inductive probe.

Please let me know how it goes.

I also agree that BIG expensive power inductors can be used to stretch the charging pulse and therby reduce ripple. It is rare to find this on most amps out there. I think Nelson Pass discusses this very technique on his DIY website devoted to the designs of his Aleph knock-offs.

Thanks for not giving in to the entropy.