The Truth About Power Cords and there "Real" Price to Performance


This is a journey through real life experiences from you to everyone that cares to educate themselves. I must admit that I was not a believer in power cords and how they affect sound in your system. I from the camp that believed that the speaker provided 75% of the sound signature then your source then components but never the power cord. Until that magic day I along with another highly acclaimed AudioGoner who I will keep anatomist ran through a few cables in quite a few different systems and was "WOWED" at what I heard. That being said cable I know that I am not the only believer and that is why there are so many power cord/cable companies out there that range from $50 to 20-30 thousand dollars and above. So I like most of you have to scratch my head and ask where do I begin what brand and product and what should i really pay for it?

The purpose of this discussion to get some honest feed back on Price to Performance from you the end user to us here in the community.

Please fire away!


 


128x128blumartini

twoleftears
1,947 posts
11-20-2019 10:36am
"Any way you slice it, Noel Lee has a lot to answer for."

What exactly should Noel Lee answer for? 
It is not a Zobel network, though it looks the same, it performs a much different function.

A Zobel network is placed, typically across the woofer, so that as the impedance of the woofer goes up, the Zobel network simulates a constant impedance. That constant impedance allows the crossover to work properly. These were used in speakers well before Polk.


Polk patented putting an RC-damper/snubber across the speaker terminals. The purpose of this was to dampen high frequency oscillations.

turnbowm50 posts11-20-2019 2:14pm
atdavid
432 posts11-20-2019 10:10am"Originally patented by Polk 30ish years ago."

Matt Polk did indeed patent the use of Zobel networks in loudspeakers. That was in response to power amps self-destructing when using Polk’s high-capacitance Cobra speaker cables.

The concept of Zobel networks, however, was developed by Otto Zobel of Bell Labs in 1923.

atdavid,

How is the series R-C network (Zobel) that is used to provide a constant impedance different from the series R-C circuit used by Polk to dampen power amp oscillations? To me, they serve a dual purpose.

I thought you might find this excerpt from Nelson Pass's discussion of speaker cables to be of interest. ...

"After a period of confusion, Matt Polk and I realized independently tahat the lack of a characteristic termination was causing the problem. Polk developed and patented a "damper" consisting of a .047uF capacitor and 6 ohm resistor in series placed across the loudspeaker, while I used the same network but with .1uF and 5 ohms. The results of this network are seen in Fig. 8 where the resonance in the pulsed waveform is damped out, restoring stability to an otherwise oscillating amplifier. Since Polk's commercial introduction of the damper circuit we have found it cures oscillation problems caused by the other exotic low inductance cables. It is necessary whenever a reasonably long length (>3 feet) of low inductance cable is mated with any wide bandwidth amplifier. It interacts unfavorably with twin lead conductors (Fig. 8) which require higher impedance values (say, .01uF, 60(2); however, twin lead's higher characteristic impedance and resonant frequencies are in any case unlikely to induce oscillation in amplifiers now available."  
https://www.passlabs.com/press/speaker-cables-science-or-snake-oil
For the same reason an RC-snubber across a diode or FET is not a Zobel network ....
atdavid438 posts11-20-2019 1:00pm"For the same reason an RC-snubber across a diode or FET is not a Zobel network ...."

They both have a resistor in series with a capacitor. To me, that makes them the same except for the name. I guess we'll have to agree to disagree.