Power Cord Length


Here's one for the electric wizards to kick around. Whilst attending Axpona this weekend I was doing some power cord shopping. At one particular display I was being told by a very well known cable company representative, I'll not mention the name so it doesn't influence any responses, that the rule of thumb is that in order for the pwr cord to be effective it needs to be at least five feet long. This allows the current to be in the cord long enough for it to be effective. Ok, I'm really dumb when it comes to this sort of thing so maybe I said that in the most simpliest of words but that's pretty much how it was explained. Anyone care to elaborate on this good or bad?
jackcoke
Jim (Jea48), thanks for providing the Nordost quote and link. I’d have to say that those recommendations don’t say anything positive about their credibility as a cable manufacturer, as far as I am concerned. In addition to the lack of supporting rationale, the recommendations for analog interconnects, tonearm cables, and speaker cables are one size fits all recommendations that make no sense IMO.

The degree of virtually all explainable effects of line-level analog interconnects and speaker cables (including those whose audible significance is debatable or doubtful) is directly proportional to length. That would include the effects of resistance, inductance, capacitance, skin effect, proximity effect, dielectric absorption, and propagation delay, among several others that could be cited. Therefore if the goal is for those types of cables to behave in as neutral and uncolored a manner as possible, the shorter they are the better. In fact an advantage of monoblock power amps that is often cited is that they make the use of very short speaker cables practicable, thereby minimizing their effects.

The only effects of line-level analog interconnects and speaker cables I can think of that would not be directly proportional to length would be antenna effects, that could conceivably result under some circumstances in audibly significant pickup or radiation of RFI/EMI. But even in that case it would seem expectable that the shorter the cable is the better.

And when it comes to tonearm cables, their one size fits all recommendation ignores differences between moving magnet cartridges (for which the sum of cable capacitance, phono stage input capacitance, and tonearm wiring capacitance should conform to the recommendation of the manufacturer of the particular cartridge), and low output moving coil cartridges (for which minimization of capacitance is generally desirable, but the significance of which is highly dependent on the particular phono stage and the particular cartridge).

I’ll give them some credit, though, for the 1.5 meter digital cable recommendation, which as you are aware has been well explained technically, and well documented anecdotally. Although even that recommendation will in many cases not be optimal (that possibility also having been well documented anecdotally). 1.5 meters should be thought of as having the best odds of being optimal (unless a very short length is practicable, such as 6 or 8 inches), but there will be a significant number of cases in which 1 meter or some other length will prove to be a better choice, as the optimal length depends on many unknown and unpredictable component and cable dependent variables. The risetimes and falltimes of the signal provided by the component which drives the cable being one very significant variable, that is almost always unspecified and unknown. Numerous other variables that affect what length will be optimal could also be cited.

Regards,
-- Al

Almarg wrote,

" I’d have to say that those recommendations don’t say anything positive about their credibility as a cable manufacturer, as far as I am concerned. In addition to the lack of supporting rationale, the recommendations for analog interconnects, tonearm cables, and speaker cables are one size fits all recommendations that make no sense IMO."

I hate to judge too harshly but it would appear the high end audio community, I.e., the high end shows, the reviewers, the magazines that publish Class A components and the audiophiles themselves disagree with your assessment as Nordost has been at or near the top of the pecking order for quite some time. What is it, 25 years? You would be wise to audio Nordost Valhalla cables. 

Cheers

geoff kait



Geoff, my post was not an "assessment" of Nordost cables, and said nothing about their sonics or their desirability.  It appears that you've read things into my post that it didn't say.

Regards,
-- Al
 
Post removed 

I hate to judge too harshly but it would appear the high end audio community, I.e., the high end shows, the reviewers, the magazines that publish Class A components and the audiophiles themselves disagree with your assessment as Nordost has been at or near the top of the pecking order for quite some time.

I hate to judge too harshly



geoff kait,

Then don’t!