At audio frequencies the impedance of coax is quite low. For instance at DC, the Belden 1505A has only 10 ohms per 1000 ft (or 0.01 ohm per foot). The conductor is solid copper, not copper coated steel. I'm not sure on what basis you are making your statements...
Here's the MFG datasheet on 1505A:
http://www.belden.com/techdatas/english/1505A.pdf
-Charlie
I've been away from the forum, but two points:
1] Co-ax RG6-QS (Quad Shield) is optimized for CATV and cable TV, TV channel frequencies. It's as far from good audio interconnect cable as you can get.
2] That 75 Ohm value refers to the radio frequency characteristic impedance. It is measured from the center conductor to the shield, at radio frequencies. If you measure the characteristic impedance at DC the value approaches infinity. You can easily do this with your Ohm meter.
For good unbalanced analog interconnects, you want a co-ax cable with very low end to end shield resistance. (something that RG6-QS fails)
1] Co-ax RG6-QS (Quad Shield) is optimized for CATV and cable TV, TV channel frequencies. It's as far from good audio interconnect cable as you can get.
2] That 75 Ohm value refers to the radio frequency characteristic impedance. It is measured from the center conductor to the shield, at radio frequencies. If you measure the characteristic impedance at DC the value approaches infinity. You can easily do this with your Ohm meter.
For good unbalanced analog interconnects, you want a co-ax cable with very low end to end shield resistance. (something that RG6-QS fails)
Even though I'm using "respectable" speaker cables and interconnects (Kimber Kable 8TC's and PBJ's), and they sound fine, they don't have anything to do with DIY, and I think I can build better.
I'm going to try a variation of this design, at .5 Meters (Minus the ferrite core)
DIY Silver RCA Interconnect Cables
I expect them to sing.
I'm going to try a variation of this design, at .5 Meters (Minus the ferrite core)
DIY Silver RCA Interconnect Cables
I expect them to sing.
I did make interconnect according Christ VH design but using material I bought from ebay and add little improvisation.
For silver wire I bought 28 awg upocc from someone in taiwan, teflon core from local shop also other materials except 3mm cotton tubing from partsconnexion.
RCA is Eichmann cooper CuTe + WBT solder.
The improvisation I made is to cover the entire teflon core with big cotton tubing before I attached silver wire in double helix configuration which is also covered with small cotton tubing, anything else was the same according Chris design.
Sound character I describe is live and dynamic sound but smooth, good detail and good staging but still maintain the musicality. I compared with my stock Harmonic Technology Prosilway mk II, Chris's interconnect easily beat the HT interconnect, honestly no comparison.
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If that is what Whitlock says then it is not as simple as that.
In some situations a twisted pair performs better than coax.
Andrew, why and how could that possibly be?
We are talking about unbalanced analog RCA interconnects, aren't we?
We are talking about unbalanced analog RCA interconnects, aren't we?
From Henry W. Ott:
"Balanced vs. Unbalanced Audio System Interconnections"
Use cables with a copper braid (or even spiral copper) shield instead of a foil shield.
Use cables with the heaviest shield possible, or with double shields in order to minimize cable shield
resistance. Do not use cables with aluminum foil shields, since their resistances are much
higher. (Note: A foil-braid combination shield is fine, as long as the low resistance
copper braid is present). Also keep cables as short as possible, since this will also reduce
the total shield resistance.
http://www.hottconsultants.com/pdf_files/Audio Interconnections.pdf
"Balanced vs. Unbalanced Audio System Interconnections"
Use cables with a copper braid (or even spiral copper) shield instead of a foil shield.
Use cables with the heaviest shield possible, or with double shields in order to minimize cable shield
resistance. Do not use cables with aluminum foil shields, since their resistances are much
higher. (Note: A foil-braid combination shield is fine, as long as the low resistance
copper braid is present). Also keep cables as short as possible, since this will also reduce
the total shield resistance.
http://www.hottconsultants.com/pdf_files/Audio Interconnections.pdf
From Table in Figure 2-27 (page 72):
Coax = 27 dB Attenuation
Twisted pair = 13 dB Attenuation
and that's at 50 kHz.
Note: There are several pages of fine print that go along with that simple table.
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