Another pc non-believer hits the dust

S Clark · « **on:** 4 Sep 2009, 05:54 am »

Jeez I just love it when you tell an engineer how much difference a power cable can make in the sound of a source in you system. Invariably they give you that look that says " I'm an engineer, and I know that that's BS. Obviously the last 5 feet of wire that carries current.... blah, blah, blah " Then you set them down and make them listen. Next come the questions . Did you change the volume? Are you sure that the only thing you changed was the power cable? Then the denial . "That can't be." "It isn't possible". And finally the acceptance..
"I'm stunned", "I wound never have believed it" etc.

After the wives went to bed, I put a set of regular power cords on my Cambridge cdp, listened to several bits, and replace it with the Electra Cable 6 wire braid cable. My engineer buddy was floored. No arguements from him about placebo effect, just acceptance that the Electra made a difference in clarity and reality.

nonoise · « **Reply #1 on:** 28 Sep 2009, 04:38 am »

My friend, who brags "who has the degree here?" claims he doesn't hear a difference but I know he does. Then he claims that his hearing was damaged during the military and then goes on about his time as a camera man and his editing experience (which is all true) and requires a keen ear but it all boils down to an indifference on his part to all things musical. He loves his I-pod based car system and there's no convincing him of the difference.
Yet every time I change a cable there is that difference that is so easy to hear.
Go figure.

mfsoa · « **Reply #2 on:** 28 Sep 2009, 02:59 pm »

I did the same thing to the engineer who actually built the amp we were listening to, with the same response -
'It can't be...there's no way...but how could..." turned into "Wow, that's really an amazing difference, I never would have thought so"

Fun stuff!

-Mike

Charles Calkins · « **Reply #3 on:** 28 Sep 2009, 04:52 pm »

Hard for me to believe that just a power cord would make such a difference. Not saying that it isn't a fact but just hard to believe.

Cheers
Charlie

BobM · « **Reply #4 on:** 28 Sep 2009, 05:17 pm »

Hard for me to believe in aliens either, but we have several who are members of the NY Audio Rave.

Seriously, the only way to relieve doubt is to try it for yourself. Textbooks will not give you the true answer.

Charles Calkins · « **Reply #5 on:** 28 Sep 2009, 05:45 pm »

Quote from: BobM on 28 Sep 2009, 05:17 pm

Seriously, the only way to relieve doubt is to try it for yourself. Textbooks will not give you the true answer.

I wouldn't have a clue as where to start. I do know that PC's can be very expensive. I use an Oppo 980 as a CD player. Maybe a top notch PC won't do it any good.

Cheers
Charlie

zacster · « **Reply #6 on:** 28 Sep 2009, 07:25 pm »

I never much believed in them either, but I did hear a distinct difference at the last NYAR I was at over at Paul's with his own built cords. That said, I still have 18ga lamp cord going to my amp.

hoxuanduc · « **Reply #7 on:** 28 Sep 2009, 07:37 pm »

Quote from: Charles Calkins on 28 Sep 2009, 05:45 pm

Quote from: BobM on 28 Sep 2009, 05:17 pm

Seriously, the only way to relieve doubt is to try it for yourself. Textbooks will not give you the true answer.
I wouldn't have a clue as where to start. I do know that PC's can be very expensive. I use an Oppo 980 as a CD player. Maybe a top notch PC won't do it any good.

Cheers
Charlie

Here's a DIY recipe that's not too expensive...

http://audiotweaks.com/diy/bobcrump_pc/page01.htm

Duc

Browntrout · « **Reply #8 on:** 28 Sep 2009, 07:45 pm »

This is something I've never understood. You see text books DO explain why having a thick low resistance good quality conductor as a power cord for something that requires current in a time dependant manner is beneficial.

Quite simply the number of electrons available is determined by the material and the amount of it. So where the number of electrons passing a point in a certain time is current then the larger the number of electrons per cross sectional area the less 'flow' of electrons is required for the same number to pass that point in a certain time and therefore the TIME needed to provide that current (charge / time) is LESS.

So a thick pure polished conductor will provide current more quickly when demanded by the device and as music is pretty time dependant we can hear the difference. It's not rocket science.

Regalma · « **Reply #9 on:** 28 Sep 2009, 07:56 pm »

Without getting into the PC debate I'll just point out that once the conductor gets above a certain size the rate that current can flow will be greater than the rate the device consumes it. In rare cases peaks flow rates may exceed that level, maybe, but the various components in the power supply of the device will act to buffer this very effectively. Besides, most people seem to notice the greatest difference between PCs when they are used on source devices, which use very little current.

Further, the largest gauge wiring you are likely to find in houseiwiring is 10 AWG. That will be the real limit of current flow rate.

I believe we need to look elsewhere to explain any effect.

Browntrout · « **Reply #10 on:** 28 Sep 2009, 08:10 pm »

In fact while I'm here I'l explain why the common argument about ''the last five feet of wire when the power comes all the way from the power station'' argument is laughable.

If the current and voltage measure the same across the high end power cord attached to the amp and across the ring main cable how can there be any effect? Well the cable nearest the amp provides the greatest determining factor with respect to current delivery.
So if you had the amp attached to ring main cable then the high end power cord you would not hear any where near as much an improvement. Why?

It is all to do with the compressive nature of electron flow, now some people will tell you that the moment a potential acts across a wire an electron 'flow' starts and the idea that there is no time delay between an electron at one end reacting to the potential and an electron at the other end reacting is incorrect.
I hope you bear with me as I've realised how difficult this is to explain half way through typing

The best way for me to describe it is to say that there is an available 'front' of charge a bit like the wall of a high breaking wave and it is the proximity of this 'front of charge' and it's breadth that most affects the devices ability to draw current and how 'instantaneously' it appears to the device.

In stupid simple terms if you suck on a thin long hose pipe that is full of water and sealed at the other end you will manage to get a small amount of water into your mouth, yes?
If you suck on a thick long hose full of water and sealed at the other end you will manage to get a larger amount of water into your mouth.
I hate to use water anaolgies for describing electricity as it is not actually what happens but it (to me at this time) seems analogous of what I'm trying to get across.
There you go, few, we never have to ask why power cords work again, feels good does it not?

Browntrout · « **Reply #11 on:** 28 Sep 2009, 08:12 pm »

Regalma it is not the peak current but the time it takes to respond to the demand that makes the difference.

BobM · « **Reply #12 on:** 28 Sep 2009, 08:26 pm »

I don't think the pipe full of water analogy truly holds up. Yes, it rings true and creates a nice visual, but it doesn't explain the fact that power cords do make a difference, while larger plumbing does nothing to improve the sound of my system.

bpape · « **Reply #13 on:** 28 Sep 2009, 08:41 pm »

Nope. But, it does give you more consistent pressure and keep you from getting just a drip in the shower when the washing machine turns on...

Bryan

Wayner · « **Reply #14 on:** 28 Sep 2009, 08:46 pm »

I'd like to correct a few comments about the nature of electricity and I promise to keep my mouth shut about the PC theories in this thread.

First, electron displacement travel at the beginning, middle or end of a conductor is at approximately the speed of light. The ampacity of any given conductor is it's ability to pass current with out becoming "plasmatic" where it's shape and structure become at risk. If you will notice the usual writing on cables, they may say something like 16/3 awg, 75 degree C, dry location. What this statement says is that the ampacity of the cord is 13 amps in an environment of 75 degrees C or less and not in contact with water. If the temperature of around the cord became hotter then 75 degrees C, then its amperage carrying would have to be derated, buy the number of conductors, the actual temperature and other factors. In a bolted dead short situation, that little 16/3 cord could carry 50,000 amps for a short period of time and would result in a massive explosion, described by the NFPA 79e as "Arc Flash", tho it is usually associated with much higher voltage/current carrying conductors such as those found in 208 or 480 volt 3 phase power feeds. During the micro-seconds after an arc flash explosion, the temperature of the air will exceed the temperature of the surface of the sun, the copper conductor will vaporize and the resulting explosion will hurl the victim to other area some distance away, usually resulting in death.

Now lets say we have a CD player that draws 13 watt. At 120 volts that would make the current draw (I=P/E), 13/120 = .108 amps. At this amperage draw, we are allready at 120 times the actual size needed for the device.

If we look at the DC resistance of the wire for 16 awg, it is 4.99 ohms per Kft. 10 awg would be 1.24 ohms per Kft. The ampacity for 10 awg wire @ 75 degrees C would be 50 amps, or 462 times the required ampacity of the device.

Considering that most cables are only 6 feet long, the resistance factor is basically non-existent. So, While the CD player's power supply has lots of weird things going on inside, like conduction, capacitance and resistance, the ability for the 16 awg cord to deliver the goods (electron flow) with a safety factor of 120 is very interesting, no?

Wayner

S Clark · « **Reply #15 on:** 28 Sep 2009, 10:53 pm »

Well, I certainly don't have an explanation, but it isn't really a concern for me. The fact is that I heard a very big difference, not subtle, not slight... but a BIG difference when changing from the stock PC on my Cambridge cdp to the 7 wire Electra. It took me perhaps, oh maybe, 5 seconds to overcome my rather ingrained skepticism about PC and wire in general. Therefore, the need for a technical explanation is academic.

Bob in St. Louis · « **Reply #16 on:** 28 Sep 2009, 11:54 pm »

Quote from: S Clark on 28 Sep 2009, 10:53 pm

Therefore, the need for a technical explanation is academic.

Kinda like requiring an explanation of why drinking alcohol or having sexual intercourse makes you feel good?

Bob

Wind Chaser · « **Reply #17 on:** 29 Sep 2009, 12:02 am »

Drinking alcohol does not makes me feel good... stupid, yeah... but not good.

Sexual intercourse? What's that?

Bob in St. Louis · « **Reply #18 on:** 29 Sep 2009, 12:06 am »

Sounds to me like you're not doing either one correctly.

Sorry for the OT.

Bob

brj · « **Reply #19 on:** 29 Sep 2009, 12:10 am »

Just a quick note from your friendly neighborhood co-facilitator, folks...

Topic wandering is definitely expected up to a point, and this conversation has been entirely civil so far (kudos!), but this is a review thread rather than a lab discussion. Past experience has shown that cable debates can get ugly quickly, so please try and stay focused on the specific cable under review.

Thanks!