I think it's clear from the entirety of this discussion that each system requires its own unique treatments in terms of electrical and mechanical conditions. However, I do agree that there are some activities which will transcend the individuality of the system, and be virtually universal in their behavior.
#1 - Make sure your power is clean, and constant, regardless of the methods used to achieve that.
#2 - Reduce stray hum, RFI, and EMI fields surrounding your equipment, and block, or otherwise deter these fields from affecting your equipment, including cables.
#3 - Consider your equipment and cables to be "vibration antennas" and attempt to reduce, or control, the mechanical resonances that may be induced by external sources. Attempts to control inherent, natural resonant frequencies can be counterproductive.
#4 - Remember that all signal carrying wires have an inductive field around them that is actually a part of the signal. Attempts to suppress this will affect the quality of the signal in the wire. Allowing these unsuppressed fields to interact with other unsuppressed signal carrying wires could be detrimental to sound.
#5 - Place transformers and other large magnetic field generating devices far enough away from sensitive items which may be influenced by the fields.
#6 - Just because it may be difficult/expensive to do something behind the wall does not mean that you may not reap improvements from these efforts. It is a known fact the the Romex moves enough from its own movement inside the wall, that it can cause a connection to sever from metal fatique, and this is why the Romex is to be stapled within several inches of the rough-in box. We haven't even discussed whether the conductive staples on the Romex could be a factor, when these are plentiful, and in direct contact with the Romex sheath, and even pinching the wire in some cases. Maybe non-conductive staples may play a part. Maybe distance between staples may have some electrical or mechanical effect.
#7 - Make good, clean connections wherever any connection is to be made, and periodically clean them. Including in the outlet boxes, and breakers.
#8 - Use good grounding tecniques.
#9 - If power conditioning is required in your area, due to grungy power from the street at varying times of day, use it.
#10 - Use your ears to decide the value of the modification. |
Albertporter - something just occurred to me form waht you said. I do not mean to kick a dead-horse, but since you say that the 2-channel system is affected when the subs are plugged-in, but not turned-on, I suspect a ground-loop may be at fault. Usually these cause hum, but not always. One way you can test this hypothesis is to leave the subs on and plugged-in , but disconnect the IC's to both subs. If this has the same improvement effect as unplugging power to them, then it is definitely a ground-loop at fault.
If this is the case, the cleanest solution to this is either to unground both subs with AC cheater plugs or run isolation transformers to one or both subs. |
Do power cables make a sizeable difference? I'm no technical expert, but I'd like to share my experience.
Until a month ago, despite having a high end system (comprising Capitole MKII, KR8000 monos etc.) I was a total disbeliever in power cords. All power cords in my system were stock cords. Soundwise, I was satisfied.
For quite a while I had been wanting to try quality power cords, but there are no dealers in my country, Mauritius, which is close to South Africa is very far away from the US and Europe and dealers whom I contacted for a trial often limited the money back policy to one month. Since postage & customs formalities would take about two weeks for the products to reach me, there would hardly be any time left to audition and return the cables within the specified limit. The risk was too much.
A few weeks ago, I decided to make my own power cords with some Audio Note AN-D speaker cables (retails for about $10/metre). I made 3 cords; those on the power amps were grounded while the one on the CD player was not.
Result: well, after two days, I could not believe my ears. A huge amelioration in musicality, smoothness, detail and soundstage. Almost creamy and gently massaging my ears.
To be honest, my experience tells me that the addition of power cords had a better impact in my system than my Audio Aero Capitole MKII replacing my Micromega Stage 6.
I don't know whether that would apply to every system, but my advice is, one audition is better than 100 debates, as already mentioned ealier in this thread.
Since I am curious to know how far the performance of my system can extend, I am still willing to try megabucks power cords but can't find any dealer willing to send me 3 so-called high end PCs for a 2 months trial period, everything paid in advance, but fully refundable. I am even willing to pay a fee of $100 for the trial if I don't end up buying any of the three cords sent to me. Anybody (including fellow audiogoners) willing to help? thnks.
Dr Jawa Lallchand
Mauritius |
My sub woofers can present a problem for the main system in that they affect resolution and distortion levels of my Soundlab U-1.
That being said, this is a two channel issue and since the subs are a deterrent to stereo sound quality, they are not supplied with signal.
However, power even being AVAILABLE to the subs in an inoperative mode damages the reproduction quality of the Soundlabs.
I have my own opinions as to the cause, but since the HT system is used three hours a week, and this is not a problem with Dolby 5.1, the solution is to save electricity and unplug the offending product.
I do the same thing with my DSS receiver, DVD player, and Dolby 5.1 processor. Disconnecting them from the wall mains is a small but audible improvement for two channel analog reproduction.
As for details of my system's wire and cable dressing, a visit by way of my provided link makes it apparent that it is not an issue in this discussion.
As for mechanical resonances, if a system is pushed to a high enough level, solving miniscule problems can be a significant improvement.
I think this dead horse has been beaten enough.
I am confident my Purist interconnect and power cables are not an issue, and wish you success in marketing your products. |
Albertporter wrote: My comments were meant to bring to light the fact that mechanical, electrical and magnetic interference all produce changes in a high end system. I certainly agree with this. Particular systems can have effects from all of these. What I do not agree with is that mechanical resonances are one of the most important factors in a typical system. What might be happening with your powered subwoofer is that it might be using a class-D amplifier or a switching power supply. These can create large switching noise on the power line and create fields that can get picked-up as well. If this is the case, I would recommend using a ferrite on the power cord to each subwoofer. Have you tried this? Unless the other cables are draped on top of the subs, It is hard to believe that they are picking-up noise this way. |
Audioengr said: This is certainly possible. Sounds like you have a combination of magnetic field coupling and mechanical coupling from the sub. Subs put out a lot of energy that can certainly resonate the shutters and probably some component chassis. Power cords make a difference for reasons other than mechanical resonance or magnetic coupling. However, if the subs are on the same circuit as your other components, they may be causing droops in the AC line that the other components are reacting to. Sounds like a complicated problem at best. There is no way it can be diagnosed over the internet. My comments were not a cry for help, my system is pretty much full out. Please see the thread: http://forum.audiogon.com/cgi-bin/fr.pl?vaslt&1022712214&viewI have a dedicated line for every component, including all six boxes that make up my preamp. My comments were meant to bring to light the fact that mechanical, electrical and magnetic interference all produce changes in a high end system. The sub woofer affects the Soundlabs when there is NO signal going to it and it is sitting idle, two feet from each Soundlab. The fact that the internal amp is on creates enough problems to hear during two channel playback. Hope that explains my point more clearly. For what it is worth, each position in my system has been tested with a dozen or more better known products. I liked several of these, but ultimately the Purist Dominus was first choice for two channel and Proteus and Venustus for the HT system. |
Nikkidanjo wrote: I'm not talking about mechanical resonance, I'm talking about EMI from equipment feeding back into the system through the power cord. This sort of phenomena would happen if you placed unshielded interconnects right next to your speaker wire. The output signal would then be fed back into the amp in some form. I got what you are talking about. This is a common misconception. It can happen from power cords or speaker cables to unshielded IC's. However, power cords are part of a very low impedance circuit, which as a result of being low-impedance,is not susceptable to pick-up of RFI or stray magnetic fields. This is also the case with speaker cables. Even if they did pick-up some high-frequency noise, this would be immediately filtered by the AC transformer in the component. Power cords radiate fields, but do not pick-up much because they are low-impedance. The ferrites that are on computers, for instance are there to prevent RFI that is generated inside the box from using the ground of the power cord as an antenna. This way they pass FCC regulations. The ferrite is not there to prevent noise from entering the computer chassis. Some AC filters for PC's are useful for "surge" protection and lightning strike protection, which can damage a PC power supply. I know about this because I have been a EE for 26 years and have worked in PC design, including for Intel for 16 years. On the other hand, if there are ground-loops created by several power cords being plugged into one or more circuits, this is an entirely different story. This ground loop makes a very nice antenna for RF or AC pick-up. Shielding these cords will have no effect whatsoever on the ground-loop unless it lowers the ground-wire resistance a bit. The only real fix is to break the ground-loop or go to balanced interconnects. |
Frap - I believe that resistance played a part in the added 2 feet, and inductance as well. The 16 gauge cable 2 feet long can have the resistance of 20 feet or more of 14 AWG ROMEX. It has the inductance of about 12 feet of ROMEX. So this was like adding 20 more feet of ROMEX to the circuit.
I agree with you on the air dielectric being the best, however the goal with a power cord is low inductance and resistance. This means large conductors or lots of smaller conductors that are tightly magnetically coupled. Some cords do not do this coupling well and the result is excessive stray magnetic fields. Power cords do not "pick-up" stray fields, but they do create them. If you have unshielded interconnects running side-by-side with a power cord to an amp, you might pick-up some magnetic crosstalk in the interconnect. Incidently, shielding a power cord is a bad idea, IMO, because it adds unnecessary capacitance. Typical shielding also will not stop the stray magnetic fields for the most part. You need MU metal shielding to do this. |
Albertporter wrote: "I have Soundlab Ultimate One speakers, and the brands of AC cables connected to them and to my (home theatre use only ) sub woofers make a huge difference in sound. Crazier still, disconnect the sub woofers from the wall and the performance of the Soundlab is improved. The amplifier and resulting magnetic field of the sub woofer ARE interacting with my Soundlab."
This is certainly possible. Sounds like you have a combination of magnetic field coupling and mechanical coupling from the sub. Subs put out a lot of energy that can certainly resonate the shutters and probably some component chassis. Power cords make a difference for reasons other than mechanical resonance or magnetic coupling. However, if the subs are on the same circuit as your other components, they may be causing droops in the AC line that the other components are reacting to. Sounds like a complicated problem at best. There is no way it can be diagnosed over the internet.
The thing I want to point out is that it is easy to get sidetracked from root-causing the real problem, particularly if the physics is not well understood. I have seen posters change interconnect cables over and over to solve a ground-loop problem, when the real problem is the AC power grounding. |
The reason is simple: They sound better. Have you listened to a better power cord yet? |
Audioengr,
To defend my honor I must clarify my statement about shielding,
"Shielding the cables as they near this big rack of electronics may make all the difference. Perhaps the worst dirt is the dirt generated by your own system feeding back into itself. This could explain why shielding may help."
I'm not talking about mechanical resonance, I'm talking about EMI from equipment feeding back into the system through the power cord. This sort of phenomena would happen if you placed unshielded interconnects right next to your speaker wire. The output signal would then be fed back into the amp in some form.
That being said, I do not make any claim how this could affect the system. I'm simply offering way that I think things could happen. I did say I know just enough to be dangerous :) |
In my own experiments, the introduction of 2 feet of stranded 16/3 extention cord onto the end of my preamp, turntable or power amp was enough to influence the sound negatively. Keep in mind, the typical 18 awg cord supplied on equipment, has a up to 7 amp capacity. Resistance played no part in the additional 2 feet. If your speakers have at least the resolving power of an LS3/5A, anyone with an open mind should be able to hear the effects.
A simple tool called an Elfix, can eaisily demonstrate the incredible amount of stray currents surrounding A/C wire.
Shielding almost always results in degredation. The ultimate dielectric is AIR, followed by glass. Since these are all near impossible to achieve in a wire, we are stuck with compromises like teflon.
As usual, everything Albert states is true. I tend to agree with BWhite as well. My guess is the wallplates will most definitely hurt the sound if they are metal.......Frank |
Audioengr, since you singled out the following quote that I gave credit as POSSIBLY being part of the explanation of why cables sound different.
"Shielding the cables as they near this big rack of electronics may make all the difference. Perhaps the worst dirt is the dirt generated by your own system feeding back into itself. This could explain why shielding may help."
YOUR RESPONSE WAS:
Sorry, but this is technically nonsense. Ask an engineer friend whether this makes any sense. You are mixing shielding from EM fields and mechanical resonances. Shielding eliminates susceptibility to crosstalk from nearby EM or magnetic fields. It does not help with mechanical resonance.
MY EXPERIENCE IS:
I have Soundlab Ultimate One speakers, and the brands of AC cables connected to them and to my ( home theatre use only ) sub woofers make a huge difference in sound. Crazier still, disconnect the sub woofers from the wall and the performance of the Soundlab is improved.
The amplifier and resulting magnetic field of the sub woofer ARE interacting with my Soundlab. This may also be proven by placing a large shield between the sub woofer and the power supply of the Soundlab. I had Purist Audio build such a shield and among a group of six listeners the change of inserting and removing was obvious to every member, every time.
I still contend that there are many things going on in an audio system all at the same time. Any number of changes in equipment and cables can effect RF, magnetic and electrical interference. I've tested TI shield, Purist's shields, Audio Prisms wall filters, dozens of audio grade power cables and ferrite blocks purchased from Ferishield in New York.
Bottom line is they all change the sound. Some can reduce one problem while messing up something else. Ferrite for instance, is not to my liking even though it can reduce or eliminate some radio signals.
As for the wall plate that Bwhite is discussing, I never said that it was effective, only that I am open minded enough to experiment.
I don't know if you are familiar with Marigo dots. They are varying size stick on dots that are manufactured from lead and other materials.
Placing a single dot the size of a pencil eraser on the end of an electrical plug DOES change the sound. The dots work on interconnect cables, equipment faceplates and even on amps beside the speaker posts.
Since these cannot possible have any electrical properties, they are effecting the mechanical properties of the component, regardless if electrical or mechanical in nature.
Seems logical then that electrical plates could contribute to the systems performance.
Anyway, the cost of such a test is miniscule. I have many failed experiments in attempt to improve my music system, but I have also found a number of things that helped.
I think it's important to keep an open mind and experiment with a eye toward learning. Closed minds seldom learn anything new. |
Audioengr - One thing I have learned in Audio is that measurements aren't necessarily worth the paper they're printed on. What measures good usually - in most cases -doesn't sound good. Measurements don't tell the whole story. I trust my ears and not fancy-schmancy SPICE simulations. Here is an Audioengr blooper: Audioengr wrote:Shielding eliminates susceptability to crosstalk from nearby EM or magnetic fields. It does not help with mechanical resonance. Duh! Anytime you increase the mass of an object you potentially change the frequencies at which the object resonantes. Adding shielding to a cable will change the mechanical resonance of everything it touches. Read a thread in Audiogon's Tech Talk Forum Entitled: Tweaks & How My System Disappeared by Jadem6 - a well respected Audiogon member who has been very diligent in tweaking his system. Most of the changes he's made have been in regard to the Mechanical Resonance of his system. But I am sure that's placebo too right? Regarding Audioengr's comments on Audiogon vs. what is stated on his website as it pertains to his discounting of the effects of Mechanical Resonance in this thread, Audioengr wrote: No contradiction. If you take the time to read the paper, you will see that I am talking about ELECTRICAL resonance, not mechanical resonance. Hmmm.. well given that the second sentence in your "FAQ on resonance" reads: Resonance can be excited by many phenomena. If you pluck a guitar string or strike a bell, they will ring at their natural resonant frequency and then decay over time due to losses in the systems. This doesn't imply that you are speaking of electrical resonance. Unless you have an electric bell. So I read further. ANYHOW get this!! I cut and pasted the text from his Resonance FAQ into a text editor, did a search and find on the text - and bingo! It doesn't even have the word *Electrical* contained in that FAQ. It doesn't say electric, electronic, or even electricity. Whatever Audioengr! What are you hiding? Audioengr wrote:
As for your metal outlet covers, I beleive that you are experiencing the placebo effect. There is no scientific explanation as to why this should make any difference whatsoever. Resonance requires a high-Q system, which this is not. Even if the outlet cover resonated, what electrical effect could this possibly have? Guess it depends on what science you subscribe to. So get this, DUDE!!! there is no electrical effect. This is what I keep saying to you. When you plug in your power cord and it snugly presses against the metal outlet cover, the mechanical properties of your power cord (and system) change. Maybe you will understand this: plastic plate + powercord + system = X metal plate + powercord + system = Y X sounds different than Y Nice math huh? When power flows through the power cord pressed against a plastic cover plate they resonate together. When power flows through the power cord with a metal cover - they resonate together (but differently). The cover plate has an effect on the power-cord and hence the rest of the system. Plastic is a bit dull sounding and metal is a bright sounding. The thicker the metal the less bright.. wood is odd sounding and not what *I* hoped it would be... the best is to just remove the plate all together. |
"I intend to purchase a couple of plates next time I visit Home Depot. Worse case I return them a few weeks later."
I cannot believe that you guys are inventing your own "snake-oil". Best of luck.
I have tried my best to actually do the science to prove which effects are significant with all types of cables. This is significantly more than 99% of the cable manufacturers do. I even publish the experiments and the results. Evidently the public is hard-pressed to read this and understand the significance. |
"Shielding the cables as they near this big rack of electronics may make all the difference. Perhaps the worst dirt is the dirt generated by your own system feeding back into itself. This could explain why shielding may help."
Sorry, but this is technically nonsense. Ask an engineer friend whether this makes any sense. You are mixing shielding from EM fields and mechanical resonances. Shielding eliminates susceptability to crosstalk from nearby EM or magnetic fields. It does not help with mechanical resonance.
"It may be a long wait before technology is developed that "proves" how some power cords work in our systems. Having heard significant improvements with several power cables, I don't intend to wait for a piece of paper telling me what I already know is true."
What is wrong with the analysis I just did above? It proves conclusively that lower inductance power cables reduce impedance to current flow by 22% or more in a typical home scenerio. Do you not understand the analysis? |
Bwhite wrote:
"Here are quotes from Audioengr's "Technical Papers" - seems he is contradicting himself in claiming that resonance is for the most part not audible"
No contradiction. If you take the time to read the paper, you will see that I am talking about ELECTRICAL resonance, not mechanical resonance. I have extensive measurement and simulation data on this effect proving that it is real.
Mechanical resonance is a second-order effect at best. Electrical resonance is more of a first-order effect.
As for your metal outlet covers, I beleive that you are experiencing the placebo effect. There is no scientific explanation as to why this should make any difference whatsoever. Resonance requires a high-Q system, which this is not. Even if the outlet cover resonated, what electrical effect could this possibly have? |
Nikkidanjo wrote:
"Basically, I don’t by the filter part unless some form of RF filter was deliberately added."
Agree 100%, power cords should not be filters, particularly on power amps.
The best analogy is that the pressure in the outlet of the pipe is the indicator of performance. If the pipe is 2" diameter for 25 feet and the last 6 feet are 6" in diameter, this will yield a much higher pressure at the outlet than if the pipe were 2" diameter the whole length. This is what happens when you add a low-inductance 6 foot cord to a 25 foot high-inductance wire in the wall. It really does work. |
Thanks Albertporter! Please - don't expect the plates to make an improvement. They will however add a noticable and somewhat annoying brightness to your system. Hopefully this will help folks understand how mechanical resonance can play a significant role in what we hear in our systems.
Also, while you're at it, and if you feel like playing... the tightness of the screws which hold the outlet to the wall make a change as well.
After trying this with several outlet covers I ultimately decided to leave them off all together in my system. Having no outlet cover so far seems better than any other material.
Now if I can just figure out how to firm up that giggly junction box in the wall without tearing my sheetrock to bits. |
Bwhite's comments may be describing some of the differences I hear with premium power cables.
Nikkidanjo may be onto something where he describes cable shielding:
"Shielding the cables as they near this big rack of electronics may make all the difference. Perhaps the worst dirt is the dirt generated by your own system feeding back into itself. This could explain why shielding may help."
It may be a long wait before technology is developed that "proves" how some power cords work in our systems. Having heard significant improvements with several power cables, I don't intend to wait for a piece of paper telling me what I already know is true.
I have not tried metal outlet plates as Bwhite describes. I would not prejudge it effectiveness, until and UNLESS I tried it for myself.
I would likely believe in Mr. White conclusion, even if it failed to improve my system. Every system is different and it would be foolish to pass up an opportunity that at least one member has been successful with, especially one that costs about what some of us spend on a large soft drink.
I intend to purchase a couple of plates next time I visit Home Depot. Worse case I return them a few weeks later. |
Audioengr. I knew you would reply! That's why I mentioned the steel or brass outlet cover. Its a sure fire way to prove mechanical resonance. Come on man, go get yourself a steel or brass outlet cover - they are cheap 2 or 3 bucks. Replace the cover you currently use with it and then let us know what you hear. Before you write this off as snake-oil you ought to experience what other people are hearing. Here are quotes from Audioengr's "Technical Papers" - seems he is contradicting himself in claiming that resonance is for the most part not audible - and discounting it as snake-oil here on Audiogon. Conclusions:
Resonance is a very real behavior in most speaker cables. The nature of the speaker load will vary both the amplitude and frequency of the resonance. The fundamental resonant frequency is primarily a function of the cable length, but
different loads can move this frequency. Resonances can become a problem if high-bandwidth amplifiers are driving high-impedance speaker loads.
Empirical Audio takes resonance seriously, so we design anti-resonant terminations into our cables to eliminate the problem. We believe that the audible "Haze" or "Veils" that often overlay music in high-end systems is in part a result of cable resonance. What he fails to mention is that there is no such thing as no resonance. Everything resonates. His "Anti-Resonant" terminations just change the frequencies at which the cable resonantes hence making it sound different - Did someone say SNAKE-OIL? Empirical Audio has taken steps to deal with resonance in our cables. We put anti-resonant terminations in our cables to reduce this effect. To understand the effect of the anti-resonant termination, we first examine a cable without the termination. Hmmm... so this confirms, you don't remove the resonance (you couldn't anyway) - you just change it. Isn't that what I said in my earlier post? -- Changing the resonant frequencies is one way that different cables sound different. |
OK I’m an electrical engineer who has never tried to play with power cords. This means I know just enough to be dangerous but not enough to really know what I’m talking about. I am not going to claim that power cords do not make a difference because I suspect they do. That said, here’s my 2 cents.
Electrical power cord as filter: I’m not convinced but… The parallel is a fuel or water filter. Water travels for miles in dirty pipes but the filter at the end is able to clean it up. This argument does not work with power cords. A power cord is the last section of pipe, not a filter at the end. As such the analogy would be miles of dirty pipe with a clean section at the end. Not adding dirt for the last few feet isn’t going to help. A power conditioner is a good analogy to the water filter. IF the power cord has some form of filtering built in, that would be different. A power cord might include a high frequency filter to clean RF noise or something. Even if the designer didn’t intend it, the geometry of the wire could make a filter of some sort (I wouldn’t put money on it). Basically, I don’t by the filter part unless some form of RF filter was deliberately added.
Electrical power cord as the last few feet of pipe: Using the water analogy
1. The original pipe was too small (ie wire gauge too small). If the power cord was too small to handle the current you could get voltage drops. My 240wpc Bryston amp came with a heavier power cord than my Bryston preamp. Thanks to V=IR loading on the power lines and cord the amp might see a significant reduction in line voltage. I would expect this to hurt amplifier performance. If your system is plugged into a power strip this voltage drop might be shared with the other components in your system.
2. The pipe has flashing around the fittings (ie the plugs don’t mate well). Maybe the issue isn’t the last few feet but the connections at the plug. Just like the issue with small gauge wire, a bad connection can cause a voltage drop. This would explain why high quality hospital plugs can make a difference.
3. The last few feet of pipe is where all the dirt is! Perhaps the power from the wall isn’t that dirty but all your equipment is really making the noise. Shielding the cables as they near this big rack of electronics may make all the difference. Perhaps the worst dirt is the dirt generated by your own system feeding back into itself. This could explain why shielding may help.
Take it for what it’s worth. Personally I think cables make some difference but I would rather spend the big money on components rather than cables.
|
Bwhite wrote:
"Make sense?"
Not to me. In fact, IMO mechanical resonances account for very little that is audible in most systems. Certainly if you put your components on a thin steel shelving unit, you might get some mechanical resonance effects, but most systems do not experience this. If anything, the electrical resonance of longer cables has a more pronounced effect. You are taking the snake-oil literature out there too seriously. Here are some papers that are not snake-oil:
Technical Papers and Audio FAQ at:
http://www.empiricalaudio.com |
Outlet quality and contact resistance is at least as important as the inductance of the power cord itself. Silver-plated brass outlets can work wonders for dynamics and detail.
Back to the question of the last 6 feet. Here are some calculations that I did to demonstrate the effect of a good 6-foot power cord:
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. |
For fun, do a little experiment, buy an inexpensive steel or brass outlet cover and install it in place of your plastic outlet covers. Plug in your system and listen.
You should notice a big change in sound.
WHY?
I will spit this out for discussion.
We cannot cure world hunger & explain every improvement we hear in audio as a direct result of decreasing capacitance and inductance while ensuring a low dielectric absorption. While this is important and the common angle to view how cables effect a system it is but a small piece of the puzzle.
Since everything resonates at certain frequencies, the wire (yes, the stuff inside our walls interconnects, and power cables) will resonate too. This is called (drum roll please...) Mechanical resonance. Mechanical resonance is particularly evident when energy is applied to something. Bang that drum again.... did you hear something?
While inductance and capacitance are very important in cable design and lets not forget dielectric.... Mechanical resonance is to a great degree what we hear when we hear differences in cables (and components). With power applied to the cable, it will resonate and thus emphasize certain frequencies, audibly changing the tonal quality you hear.
Cable geometry, and material used are key in producing neato sounding cables since they can effect the frequencies which resonate and those that don't. Different conductors will all resonate differently. For example: Copper resonates at 26.530MHz, Gold at 1.729MHz, Silver at 4.046MHz, and Platinum at 21.499MHz
The effects of the resonance of the material depends on the gauge of the wire and of course whether or not it is in contact with a sound deadening substance like Teflon - rubber - Shunyata Sand ... Virtual Dynamics Iron Powder or whatever. These substrates weight down the resonance to create the sonic signature.
Make sense?
Okay how about saying it like this:
Power coming into your house is already resonating - when you plug your cool aftermarket power cord into the wall, how do you think this could effect the sound? If the cable changes the existing mechanical resonance, it will change the way your system sounds.
So when you change your electrical outlet cover to a brass or steel cover and plug in your hefty power cord, you will hear a new mechanical resonance in your system and better understand as the topic of this thread reads -- WHY EXPENSIVE CABLES WHEN ROMEX BEHIND WALL... :) |
No flames--I read a post in the Asylum by Jon Risch where he says he suspects 50% of the sound in power cords is due to proper grip... |
I may be naive and this may garner some 'flames' but ... I've got to believe that the main impact of upgrading a PC is not to do with the cable but more the CONNECTION. Hello ? There are two of them. One to wall recepticle, and one to the equipment, if I understand correctly. My guess is that if you simply unplug and replug an existing PC you'll end up with a better connection and hence, hopefully, improved sound. Cleaning these connections would help to.
Freezing them (I'm in Tahoe) - does this help ? Bummer that it only gets down to -20c here in winter and the better half would be distinctly uphappy if I opened the windows and shut down the stove to improve the sound ;-) |
Psychicanimal - Just because a cord makes a difference does not mean that the last 6 feet is somehow magical. It still has to do with the inductance of the entire run to the panel. The last 6 feet reduces the overall resistance and inductance compared to a typical "rubber" cord. Cryoed cables can perform well because they are lower resistance.
I make cords myself and you can see all of the measurements, analysis and theory on my website:
http://www.empiricalaudio.com |
Florida is not to kind weatherwise either, sounds just like yours. Maybe FL Power had to change his transformer too and it drove him out? Who knows? The guy drove me nuts for 6 months, but anything I know about hospital grade wiring, I know from him. He even went in and red chalked the slab with notes to the drywallers where he wanted the drywall glued and not screwed. He drove my electricians crazy too, but they made a mint off of him. He was paying the installers all kinds of money for "electrical favors". At first I was charging him when I saw things I wasn't making a markup on, but there came a point I gave up as my electricians charged me only the bid amount. Just one question though, being as that you went to such extremes to make your supply the best it could be; wouldn't a power plant of ample size been a better move? So that no matter what transformer you ended up with, voltage drops, spikes, etc, the power was cleaned and constant? |
Trich, I have absolutely no doubt that your comments are true. My years of listening and testing have shown me that the only absolute is "we don't really know anything."
I have no idea about the transformer, it is a 25K VA model supplied by TU Electric, and is the third one on my home in the last few years.
Between the wet tree limbs, squirrels and Texas weather, this neighborhood is hell on transformers. That being said, the last two sounded identical as far as I could tell. |
Hi Albert. You are correct, I did not read your entire post. I got to where you were explaining the lengths you had gone to improve your service, and stopped there. Now that I have read the entire post, I have a couple of questions for you. Is your private transformer a pole or slab transformer? Can you tell me the manufacturer and model number of the unit. The reason I ask is that I was a custom home builder, built a home for a Doctor who had about a $150k system a few years back. This guy was driving me nuts trying to get me to change his transformer because he was having to spend thousands of dollars on hi end power cords, and he blamed the transformer (also private, but because of his location). I spent an entire evening at his home listening very carefully to his system, while he switched power cords to prove his point. And he was right, the expensive power cords did make the system sound better. But his argument was that he did not previously need them. Finally I called in a favor with a friend at FL Power, and had a new transformer installed for the Doc. It was by a different manufacturer. Not even a day passed and the Doc was on the phone to me inviting me for dinner and thanking me over and over. He wanted to prove to me that he was not nuts, so I accepted. We went through the identical listening tests as with the other transformer, switching pc's, but this time - NO DIFFERENCE could be distinguished between the expensive pc's and the stock Levinson pc's. And I have to say that his system just sounded better over all. There was one pc that did seem to sound different out of the 10 or more we listened to, but I can't honestly say it was better. At the end of the evening, the Doc gave me a $500.00 tip and told me I had "saved his system". So, if you have a room full of people that all hear when you switch pc's, I would say that it is very possible that you have a bad transformer. I don't mean defective, as FL Power tested his old transformer, found nothing wrong with it and installed it on another street. Jerry, my friend at FL P did tell me confidentially that the difference between the two transformers was aluminum. One used some, the other did not. So, if you can tell me the brand and model of yours, I will drive up to the Doc's home (he no longer lives there, but I can still check the transformer). And it just so happens that the very next home I built has the same type of transformer (I had become keen to noticing this by now) as the one I replaced on the Doc's home, so I can check it too. I doubt there are that many manufacturers of transformers commonly used by power companies, so I've got a feeling you may not have even heard your system at it's best yet. |
¿Nonsense?
1) I'm hearing it.
2) I thoroughly read Bybee's website and non-mathematical explanation.
3) This is also congruent with George Tice's viewpoints.
I have no electrical background, but I had a Materials Science Engineering roommate in college. Everything they do is related to crystal structure. Cryogenics deals with ordering (reducing the entropy) of the crystal structure. Electrons behave both as particles and as waves. Noise floor in the conductor lowers as a result of rearranging the particles in space--that's a no brainer to me. There's a lot we don't know for sure...
A few weeks ago I was studying for a pre-employment chemistry test and while reading about orbitals and crystal structure it all clicked in place.
What are the basic scientific activities?
1) Observation (hearing, smelling, etc)
2) Search for regularities
3) Investigating the why
4) Communicating findings
Will, just send one of your power cords that you have two of for cryo and do your own experiment. Other people have been doing it and posting their results in other forums.
Now that Sean has a ONEAC noise reading device we'll be able to conduct some experiments on noise control tactics and get numerical data.
Until then, don't knock it 'till you try it... |
"It's in the very last feet that the electric particles/waveform gets shaped prior to entering the audio component. As such, there will be a profound influence on sonics."
This is nonsense and technically incorrect. Just because some saleman says does not make it true. The network created by the conductors from the transformer and then from the panel to the outlet and then from outlet to the component all contributes. You can easily perform a SPICE simulation on this simple model.
There is nothing magical about the last 6-10 feet of wire unless perhaps it has a transmission-line termination in the plug or on the cord. An added network of this sort COULD prevent/reduce high-frequency reflections or resonance on the overall wired network. Whether transmission-line effects occur and if so, whether they would affect the delivery of power is debatable and difficult to prove. |
Psychicanimal,
Would you please provide references/documentation for this statement: "It's in the very last feet that the electric particles/waveform gets shaped prior to entering the audio component."
Don't hear more than I'm saying. I'm not challenging the statement, I just want to know its scientific basis, as opposed to the opinion of the individual that makes and sells the cords.
Many thanks,
will |
Trich727, you must have somehow completely overlooked my post. |
There's something that Bill Parish (GTT Audio/Absolute Power Cord) taught me: "The last eight feet (of power line) are the most important."
A year later I have a very clear idea on this subject--and also why cryogenics is the most cost effective treatment. It's in the very last feet that the electric particles/waveform gets shaped prior to entering the audio component. As such, there will be a profound influence on sonics. Tice TPT, cryogenics, Bybee filters--they all work on some aspect(s) of reorganizing the particles/waveform prior to entering the audio component.
This has been THE most important lesson I've learned since coming back to the hobby after a five to six year break. |
It's interesting that no one seems to disagree with what I said earlier in this thread, and no one is saying that expensive pc's are a good investment. That must tell you something. Tom |
Different wire guages, certainly, and different types of insulation so that some must be run in conduit, other run in open, etc. depending on local codes.
We're absolutely in agreement on this point: Buy what you can hear.
will |
Right/Exactly: The Absolute cords are probably UL and NFPA rated for a piece of audio equipment (so is lamp cord), not hospital equipment. They are giving the impression they are better than they are by putting in terms like Hospital Grade and then adding the fine print later. I have nothing against those cords since people find they work. I have no direct opinion on them, because I have yet to try one. I am on your side actually Will; and I may even be more skeptical than you. I am skeptical to any or all marketing claims. I am a big believer in people trying things for themselves and forming their own opinion. I guess if everyone did that, there would be a reduced need for salespersons. (Less ads actually sounds good.) The original post mentions Romex in the wall assuming it to be poor. I assume there are different grades of Romex???
Happy listening. |
With respect, Sugarbrie, your observation is (1) not correct and (2) not directed to the point I was making. There is no legal or regulatory definition of the term "hospital grade." The way that one COULD get into difficulty would be to advertise that a cord met the various UL or NFPA standards that I mentioned when, in fact, it did not. I suppose it is remotely conceivable that one could face a suit for false or misleading advertising based on the common usage of the term but for someone to bring such a suit against an audiophile vendor would be hugely improbable. De minimus non curat lex.
But that wasn't my point. My point is that the term "hospital grade" implies nothing of audiophile interest other than heavy wire and good quality terminations. It has nothing to do with the esoteric properties often claimed for audiophile power cords.
I'm NOT talking down high-end power cords; don't get your knickers in a twist about that. I'm just informing people of what "hospital grade" means. And, perhaps more importantly from a sonic perspective, what it does not mean.
As to the Taiwan cords, ignore their use of the term "hospital grade" and see if, in the small print, they assert that the cords meet the UL and NFPA standards. That's what really counts.
will |
Hospital Grade a marketing mantra? NOT! If you tried to market any cable for any purpose by calling the parts Hopital Grade when they are not, you could be sued at the very least, and maybe arrested for fraud; because Hospital Grade is an industry standard that means something. You could sell the cheapest, most poorly made audio cable on the planet; and call it "Audiophile Grade"; because there is no industry standard that I know of.
That's a marketing mantra. So if you buy a cable with Hospital Grade parts, there is no guarantee your system will sound better, but you can at least be sure you are getting a good quality cable for your money. There is no guarantee an Audiophile Grade cable will have good EMF or RFI protection, or make your system sound better either. The only difference is the Audiophile Grade has the potential to be a piece of junk. Those $60 Absolute power cords are audiophile grade solely based on the reports that the audio equipment using them sounds good. They are massed produced by a cable company in Taiwan that can produce 6 million cables per month. They claim hopital grade in their ads, but looking at them I wonder?? (a Taiwan Hospital, not USA?) |
OK, guys. I can stifle my comments about some of the arguments presented here but this "hospital grade" stuff is over the top. How many of you really know what "hospital grade" means?
Simply put, "hospital grade" refers to:
(1) Current carrying capacity--not required to be excessive, just consistent with the power demands of the device to which it is connected. I.e. a "hospital grade" outlet on a 20 amp circuit must be capable of carrying 20 amps at a 100% duty cycle without overheating.
(2) Strain relief--sufficient to assure that if the plug is jerked from the outlet by pulling on the cord the wires will not detach from the plug and create a shock hazard.
(3) Freedom from leakage--microshock is a major concern when dealing with pacemakers (for example) thus leakage must be very, very low.
(4) Adequate grounding capacity--which many audiophiles then turn around and defeat.
(5) Assurance of power transfer from outlet to plug--accomplished by wide plug blades and outlet contacts with sufficient spring loading to assure that the contacts make tight contact with the blades. No gold, no silver, just good honest brass.
Nothing, repeat NOTHING about the "hospital grade" designation bespeaks any kind of rfi or emf protection, filtering capability, exotic capacitance or inductance characteristics, "oxygen free" copper, special conductor configurations, rocket-science dielectrics, or other esoteric properties claimed for high end power cords. The sole concerns are safety, reliability, abuse tolerance, and durability.
"Hospital grade" in audiophile circles is primarily a marketing mantra. Just wanted to clear the air a bit.
will (with 30+ years in healthcare)
References:
Underwriters Laboratories Standards UL 2601-1, UL 1778, UL 1363, UL 1449
National Fire Protection Association Life Safety Code 101 |
I once read an article about using home electrical wires for networking all the computers/control devices in a home togeather. The article went into all the well known sources for noise on the power lines and how the carrier waves were tuned to the higher frequencies to avoid all the garbage. It could be that the high dollar cables are simply acting as high pass filters for the electric signal. Different cable sound then being the result of different filtering, much like a parametric eq for power but with each cord having its own eq shape. |
I agree that relatively nominal amounts of hifi budget may be far better spent on room treatments than on the "upper level" (in price)powercords. I think part of the reason this doesn't always happen is that it is very easy to buy a PC and swap it out with the stock cord. What isn't easy is figuring out what room treatments to do, in what combination, and with what materials to address specific sonic problems.
That being said, I think there IS benefit in going with a "decent" upgrade to the power cord, but no real benefit in going hog wild on, say, a $500+ PC, unless of course you have more money than sense and don't mind lining a few pockets other than your own. I have Harmonic Tech and Ensemble PC's and they did improve the sonics of my system over the stock wire. However, I tried several more expensive cords recently (which shall remain nameless in THIS thread) and could not tell much, if any, difference. |
I also agree Fletchj for a small system; but will add that simply replacing those OEM 18 AWG cords with similar 14 AWG ones ($6 each), or the Belden Voltex shielded cables ($12 to $15 each) will still have a noticeable change for a few pennies. |
Fletchj, I could not agree more. |
If one thinks it makes an improvement to the sonics, of his system, then why not? If you have a $1000-$3000 to invest, to improve a $100,000 system, then it makes good sense. Where it doesn't make sense, in when that $300-$800, is spent on a PC, when it would make a much greater improvement, being spent elsewhere, in a $3500-$7000 system ie; room acoustics, dedicated lines, etc. |
Hi Meby,
You are mostly correct, as that is one of the concerns providing it is being plugged into a hospital grade outlet, that it will not arc. If you do not plug it into a well designed outlet, it still could. The other design approach is to limit the possibility of a short because wires can not come in contact with each other unless the cable is completely torn from the plug, and by then it wouldn't be live anyway (providing it was wired properly). Hospital grade really means nothing more than very well designed. Tom |
Ok, here is my current thought train on this; Yes, I agree that I would not want to be "hooked up" in a hospital with lamp cord and a $1.49 plug. Fortunately for me, none of my gear came with such low grade pcs. I truly doubt that when Nelson Pass sits down to design military grade circuit boards for my equipment, that he is going to cut corners on the pc. I don't think top notch designers put cheap pcs on $3k+ amps or preamps, why would they? Sure, mid-fi and lower does not go to extremes, but then you are not paying the arm and a leg in the price for those extremes. So where do I think money would be well spent as far as power goes? Drop a dedicated line from your breaker box to your gear. Get a quality 20 amp breaker (hospital rated) and use hospital rated romex, carefully run the line without staples or cable nailers to your location, and then use a hospital grade outlet(s). I really can't imagine anything better than this other than buying a power rectifying device (PS audio, Threshold), which would nullify the need to do this providing it has the capacity to meet the demand placed on it. If you buy a power supply that is not big enough for the demand, you have gained nothing. The dedicated outlet is a LOT less expensive, but would not provide all the benifits that a well designed power plant would provide. In MHO, I would keep the pc's that came with good equipment, and do one or the other properly depending on your budget. If they want to use the pc off my Threshold gear on me at the hospital, I have no problem with that. Tom |
I heard a rumor that the infamous Robert Lee @ Acoustic Zen is coming out with an inwall a/c powercable made of his Zero Crystal Copper to address this specific issue. I can't wait to try out some of that stuff. |
