aah, the yin and the yang of life. go too far one way and you tip over. too far the other and you tip over that way. Somewhere in the middle you are stable and can perform well...
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Originally Posted by apatN /img/forum/go_quote.gif
Sorry if I don't use the right terms but isn't it so that the resistance is bigger in thin wires and that is also one of the tricks to up the ohm on a headphone (beyer for example)? So, if I'm right it would pick up less noise..?
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I could be VERY far off, but beyer does not use thinner wire to increase the impedance, but so they can make the voice coils lighter. The extra impedance is a result of the goal: less moving mass.
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| And the reason for a thicker ground is that it 'flows' easier, right? |
the idea behind a "thick and thin" cable is mostly in that.
The resistance of 3FT of 40-ga wire is about 10-ohms. certainly FAR more than any practical length of 22-24ga. 3ft of 30ga has much less resistance for that length, but still more than the ground wire.
By making the resistance in the signal wire greater than the ground resistance you can sometimes avoid ground loops by FORCING the ground current through the ground wire. When they are both the same size, the ground current can flow in the signal wire and poof, you have a ground loop.
as far as capacitance is concerned, the thinner wire has less surface area. Capacitance is proportional to distance between the 2 "plates" or wires in this case and surface area. you could increase distance from wire to wire, but then you loose some noise rejection (unless you use the shield as ground as in coax). aah the fun games we play: see the balancing act.
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Originally Posted by JamesL /img/forum/go_quote.gif
How is it different from a twisted pair with single signal and single ground wire?
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if you mean using both wires in a "starquad" cable for a single ended cable, it is very similar, except that the capacatance is far higher.
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| Likewise, how is it different from a cardas litz? |
Litz-wire is a technique for making the individual wires, not the "quad"
cardas litz uses several sizes of wire in its core. cardas also individually coats EACH strand to insulate from its neighbors. most other brands use a bunch of one size of wire without coatings. there are some advantages to doing this compared to other stranded wires, but its expensive.
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| I've heard of braiding being used to minimize parallel wiring, but that's usually used for 2-channel cabling. |
braiding INCREASES capacitance. BUT if you use a whole bunch of strands you can minimize inductance (at the expense of still more capacitance). This is good for a speaker cable where you want LOW inductance, but are using a power amp which can drive a very reactive load without concern.
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| I think coax cables minimize this effect, as the shielding is distributed 360 degrees, thus canceling out the effect, but on the other hand, i've heard that shielding shouldn't be used to connect the ground. |
coax cable minimizes capacitance by using a VERY thin conductor. they also "hold" it a uniform and far distance from the shield. Both things combine to reduce capacitance. I agree, the shield should not be used as an audio ground though.
As a VERY good place to start looking into "thick and thin" cable design is the "anticable." you will need a pencil, or something similar and a decent bit of time. take a couple breaks while winding
, besides 2 feet shouldn't make a difference at all. 
