Interconnects - heatshrink v Teflon tube v tape, gauge v length

[otto88]

Hi

Several of us here at the local Melbourne (Australia) Audio Club are soon doing Mark Houston's Silver RCA Interconnect Cables project.
http://www.diyaudioprojects.com/Power/diySilver/index.htm

Mark's "recipe" calls for 3 silver wires (0.7 mm = AWG 21, from jewellers supplies here, c US $4/ m) which are sheathed individually; then a larger outer overall wrap.
For ease of building, Mark uses heatshrink for all four sheaths.

I lean towards Teflon because of its dielectric advantage. I have only a basic underdstanding, but electrical signals are propagated on the surface of a conductor.

Would that advantage more likely come in the *individual wire sheaths, or the outer wrap?

I intended to keep one of the two layers as heatshrink, to exclude oxygen.

Someone just then suggested Teflon insulation tape.
Some DIY interconnect projects have used it, available at your friendly plumber suppliers.

That would of course directly contact the silver wire, vs Teflon tube which would have to be a bit bigger, to allow the wire to be threaded through. So Teflon tape would both exclude oxygen, and may/ should keep the dielectric advantage?


most ICs will be about 1 m. I'm also doing one longer IC - 4 m (c 12 feet) - for that should I use a larger gauge, eg 1 or 1.2 mm (AWG 17 or 18)?

Comments welcome.

 

[rabbitz]

Isn't air a good dielectric and better than teflon etc?

I know you are trying to prevent corrosion as well.

 

[otto88]

Hi rabbitz

> Isn't air a good dielectric and better than teflon etc?

Yes indeed

> I know you are trying to prevent corrosion as well.

Yes again . . maybe it'd be better to use heatshrink on the 3 inner sheaths, and Teflon tube on the outer sheath?

Thanks

 

[Magura]

Enamel.


Magura

 

[otto88]

Enamel may be a a good dielectric (I don't know), but if going enameled silver wire, where could it be sourced for c $5/ m?

Cheers

 

[jacco vermeulen]

PTFE heat shrink.

 

[ssmith]

Enamel.

Magura

That's a good suggestion. I've made some IC's copying the anti-cable recipe using 22ga and 20 ga magnet wire. Costs next to nothing! Would suggest you give it a try even if you make the silver/teflon design, just to compare.

 

[otto88]

PTFE heatshrink - for inner sheaths, outer, or both?

(and what is PTFE?)

Thanks

 

[Magura]

PTFE heatshrink - for inner sheaths, outer, or both?

(and what is PTFE?)

Thanks

Google is your friend.

http://en.wikipedia.org/wiki/Teflon

Magura

 

[Magura]

That's a good suggestion. I've made some IC's copying the anti-cable recipe using 22ga and 20 ga magnet wire. Costs next to nothing! Would suggest you give it a try even if you make the silver/teflon design, just to compare.

Great way of making such, unfortunately too cheap for some.


Magura

 

[otto88]

Wikipedia says in summary

* Teflon-PTFE is a Polytetrafluoroethylene used in GoreTex and nonstick cookware.
* Teflon-PFA is a Perfluoroalkoxy used to make tubes.
* Teflon-FEP is a Fluorinated ethylene propylene

So is PTFE better for sonics?? or just more likely available (somwehere) for diy audio projects . .

Thanks

 

[otto88]

maybe for the outer sheath, cotton sleeve would also be good.

Anyone know a source for diy quantities, c 5 mm diameter?

(Diy HiFi Supply sell it, but only 2 mm)

thanks

 

[Magura]

Maybe magnet wire could also be good. Available at every second street corner, twisted pair, like 20g, will set your bank account around 2 beers back. Heatshrink in your favorite color will set you back another beer or two at the same place you got the wire.


Magura

 

[ssmith]

this is the design I tried -- somebody's attempt to copy these.

You will need:

magnet wire
a cotton shoelace
cheapo RCAs
solder

they are so cheap that there really is no reason not to make them and compare them to more fancy/expensive diy designs you may be doing.

 

[dave_gerecke]

Hello otto88, you should be able to find teflon based heatshrink, PTFE, from just about any electronics supply company. Try the website of Farnell, Newark or RS Components. These are just three companies off the top of my head. I'm not sure what distributors you have on your side of the planet, but they should have PTFE heatshrink available. Check the websites.


Peace,

Dave

 

[otto88]

Hi,

ssmith
Thanks for your info & the endorsement . .
I might do an IC shootout

Dave
We have Farnell and RS Components
Thanks, I’ll check the websites

Cheers

 

[maxro]

Just a heads-up, I recall reading somewhere about issues with teflon and silver wire. All I could find with a quick Google was:

http://www.residues.com/pdfs/foresite_teflon.pdf

 

[Steve Eddy]

I know you are trying to prevent corrosion as well.

Silver won't corrode in air at normal temperatures.

se

 

[Steve Eddy]

maybe for the outer sheath, cotton sleeve would also be good.

Why not use cotton for insulating the individual wires as well?

For that matter, since the cable is braided, why do you need an outer sheath in the first place? Just cover the individual wires with cotton, braid them up, terminate them and you're done.

Why's he using three wires for an unbalanced cable? Why not use four and double up for both the hot and ground leads? Never saw much sense in using three for unbalanced ever since I first saw the Kimber interconnects back in the 80s.

Anyone know a source for diy quantities, c 5 mm diameter?

(Diy HiFi Supply sell it, but only 2 mm)

Reference Audio Mods sells the Audio Consulting cotton braid in 2, 4, 6 and 9mm sizes.

se

 

[otto88]

> Silver won't corrode in air at normal temperatures

I think he meant oxidise, though I don’t know how much oxidation of silver effects conductivity etc.

cotton for insulating the individual wires as well?

(The idea I’ve now evolved to is heatshrink for the individual wires).
The advantages of heatshrink being easy to do, and preventing further access of the air.

> why do you need an outer sheath in the first place? Just cover the individual wires with cotton, braid them up

The outer sheath provides more robustness . .

> Why's he using three wires for an unbalanced cable? Why not use four and double up for both the hot and ground leads?

I’d have to try to contact him . .

Thanks