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DeFrag
Moderator
USA
3409 Posts |
 Posted - 02/26/2008 : 18:24:25
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Lets talk about the actual physical propagation of current for a moment.
At high frequencies, current travels near the surface of the wire because of the skin effect, resulting in increased power loss in the wire. Stranded wire might seem to reduce this effect, since the total surface area of the strands is greater than the surface area of the equivalent solid wire, but in fact a simple stranded wire will in fact have worse skin effect than a solid wire, because of its increased average resistivity, due to inclusion of air gaps within the wire. However, for many high-frequency applications, proximity effect is more severe than skin effect, & in some limited cases, simple stranded wire can reduce proximity effect. For better performance at high frequencies, litz wire, which has the individual strands insulated & twisted in special patterns, can be used.
I concur that all other things being equal, that welders cable or jumper cables which being physically larger in dimension should in fact transmit signals more efficiently & with little loss, they are still in fact stranded. Even in the average stranded guitar cable, there have been strides in different shielding configurations & jacketing techniqes which also contributes to lower signal loss from brand to brand. For instance, the shield can be woven, wrapped, etc.
Another interesting idea is the purported advantage to using oxygen-free copper (OFC) or copper which has been annealed in an oxygen-free atmosphere. We all know that copper oxidizes in the presence of oxygen & turns green & flaky; in so doing, it loses its high conductivity & deteriorates. But the amount of oxygen present in conventionally annealed, non-OFC copper is so tiny that it simply isn't a factor in cable quality. People have cut into pieces of Belden coaxial cable 25-years old that have been used in radio transmission applications & found them clean & bright, completely lacking any sign of oxidation. Modern coax is better still, with nitrogen-injected foam dielectrics that keep oxygen entirely away from the center conductor. As it is with silver, there's nothing wrong with OFC; but electrically speaking, OFC wire is indistinguishable in audio & video applications from ordinary annealed copper wire. |
Edited by - DeFrag on 02/26/2008 18:25:30 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/26/2008 : 18:41:30
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All good points DeFrag!
From Wikipedia: in copper, the skin depth at various frequencies is shown below:
frequency skin depth
60 Hz 8.57 mm
10 kHz 0.66 mm
100 kHz 0.21 mm
http://en.wikipedia.org/wiki/Skin_effect
So in normal "fine strand" audio cable, the "skin" is the entire strand and all the current would be carried by all the copper? (i.e. skin effect is negligible)
For audio power applications (speaker leads) I think it still comes back to the total surface area of the strands.
I agree 100% with your OFC comments. I have 25 year old cables that are as clean and shiny as new when you cut them.
Hence... buy welding cable for your speaker leads and spend the $23,430.37 you save on beer 
Regards,
Laurie.
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/26/2008 : 19:25:02
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Alright.. I can see now its time for the Battle of the Wits!
Princess Bride is such a great movie.
Say lauries, I think we beat this to death so.. what say you tell me about your background etc..
I think Dr. Bob would probably be as interested as I given our technical backgrounds & experiences.
Hmm.. 23 posts in only 3 days ~ 7.67 posts/day. At that rate you'll best ol' Dr. Bob in exactly 659 days, or more specifically Dec 15 2009, if he continues at HIS same rate. Two trains are... 
Wikipedia is dangerous.. I can get lost for hours following link after link..
Btw, I brew my own beer & have a couple to cook up this weekend! 
I yield.. |
Edited by - DeFrag on 02/26/2008 19:42:27 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/26/2008 : 19:53:10
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Well... honours degree in electrical engineering (started study in 1979 and finished in 1989), but haven't really ever done anything with it (been in "management"). Just futzing around with pedals etc at the moment and joined this forum because I was having trouble with a DS-2 and you guys looked both technically knowledgable and passionate. Thanks for the warm welcome!
PS: to Dr. Bob - I'm a fellow Australian - my current "Canada" location is just for a few years
PPS: don't let the "Laurie" fool you - in Australia it's short for "Laurence"
PPPS: my sincere apologies to Right Foot Boss for (almost) hijacking the thread...
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Mr Arkadin
Bronze Member
United Kingdom
119 Posts |
Posted - 02/26/2008 : 19:55:48
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Oh, yes, audiophiles  . i saw a wooden volume knob on one site (now sadly removed otherwise i would have the link) for $450 that supposedly improved you hi-fi amp's definition by removing vibrations. Or something. Anyway it was a wooden knob - that's all it was. i'm thinking of replacing all the pesky plastic knobs on my Boss pedals for wooden ones, i'm sure my tone will improve. |
Edited by - Mr Arkadin on 02/26/2008 20:01:42 |
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Mr Arkadin
Bronze Member
United Kingdom
119 Posts |
Posted - 02/26/2008 : 19:58:17
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Best cable i ever had was the Whirlwind UltraSnake with Belden cable and those solid brass connectors with a distinctive white plastic cover. Sadly they no longer make these, but i have some that have lasted me 25 years. Maybe that's why they stopped making them, because once you had a few you never needed to buy any more  . |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/26/2008 : 20:01:47
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Mr Arkadin, you ROCK! Hey... how about rock/stone knobs? "the added mass dampens undesirable audio defects"...
Of course, I can't hear all the subtle differences this audiophile stuff makes because I have cloth ears, and I don't BELIEVE. Sigh, I guess I'll have to contimue through life as a Philistine.
Laurie.
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DeFrag
Moderator
USA
3409 Posts |
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Right Foot Boss
Gold Member
USA
881 Posts |
Posted - 02/29/2008 : 03:13:39
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No problems here. Threads get hijacked all the time. I'm pretty amused by it all. Some thing to laugh at while I drink beer by myself. You guys and your technical terms and scientific knowledge.
Oh, and DeFrag I'm coming over to your place for a pint. It better be good. |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/29/2008 : 04:33:08
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| I'll cook us up a lovely smoked stout! |
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Right Foot Boss
Gold Member
USA
881 Posts |
Posted - 02/29/2008 : 04:36:24
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| Cheers to that!!! |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 02/29/2008 : 10:32:39
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quote:
Originally posted by Right Foot Boss
Some thing to laugh at while I drink beer by myself. You guys and your technical terms and scientific knowledge.
Don't be fooled, I'm usually under the affluence of incohol and just makin it up 
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 02/29/2008 : 11:51:38
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| whats the story with you guys drinking all my guinness.......anyone ever used an active lead...? our singer bought one a while back with a little graphic eq on the battery compartment for his yamaha acoustic..personally i prefer the sound he gets out of this with his cheapo yammy than his ovation electro acoustic...if he would only put a good pickup in the yamaha things would sound a lot better........... |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 02/29/2008 : 16:07:36
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| Guinness is the beer of the season! I do like Newcastle now & again. |
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jack
Platinum Member
USA
1418 Posts |
Posted - 02/29/2008 : 21:11:31
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I prefer Red Stripe... |
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Monster Cables
