DIY Copper Foil Speaker Cables Insulation Material

[moley]

Hello,


After reading hrough many threads on here about DIY copper foil speaker cables I am going to build a pair of 3.5 metre long from Mundorf copper foil.

I haven't quite got my head around what materials I am going to use to insulate the copper wire or how I will do this but I would like to ask if anyone would be so kind to answer my question on this.

One of the options I was looking at was plumbers PTFE thread tape which I would wrap around the copper foil, but as these PTFE tapes are very thin at around a tenth of 1 mm thick, I was concerned that this may not be thick enough to safely insulate the + and - runs from each other which I intend to lay on top of each other in the construction. Would voltage spikes be a concern with a thin insulation material like this? My amplifier is a 18watt SET valve amplifier so it is not a high powered beast if this is a consideration.

Perhaps a second layer of PTFE tape or a layer of packing tape made of Polyurethane or Polyester. If anyone who has made these could chime in I would be very grateful.

I saw in one of the threads someone mentioned polyurethane spray, has anyone used this in ths construction? From what I read this would help prevent oxidisation. Would a second layer of material still be needed here?

Many thanks in advance.

[weltersys]

Sounds like you are trying to make capacitors .

Packing tape will give plenty of insulation, but the whole mess will not be very flexible, if kinked it could easily short your 18watt SET valve amplifier.
I hate it when that happens

What qualities are you trying to add (that work within the audio range of hearing) compared to a speaker wire of normal construction and similar AWG?

[moley]

Hello,


Many thanks for replying. Yes it is rather like a large capacitor. I understand that this is the way that the Goertz ones are constructed and also the ones from Allen Wrights cable cookbook.

I have read alot of positive comments about these here on the forum enough to make me interested in trying this for myself. I currently have a 3.5 metre pair of TNT Ubyte DIY speaker cables that were great for the cost and would like to try something different now.

Yes cables kinking could be a problem so extra layers of insulation and something to allow strain relief would be in order.

I do not know how important the dielectric constant is or how much this would influence the performance but if I am going to take the time to build these I would like to use something with the lowest possible dielectric constant if possible.
Unfortunately the polyurethane spray looks to have a dielectric constant of around 3 vs teflon at 1.2 but I need to ensure that the cables don't oxidise. I understand that polypropylene packing tape could be used but the adhesive itself can cause a reaction and oxidisation.

[Cal Weldon]

How much will these cost to build do you think?

[454Casull]

The only thing that would happen if the foil were to oxidize would be that resistance would go up only a tiny amount.

[moley]

Hi,

It will be around £50 for the copper foil depending on which width I go for (28mm or 44mm) plus whatever I buy for insulation.

I can't find any copper foil inductors in the UK which I know some have used.

[auplater]

spray paint them black so that light reflecting off of them won't be a hindrance to your experience. You could use flexible undercoating spray for automotive applications, or maybe truck bed liner.

or you might wish to suspend them on wooden dowels so that the floor bounce effect won't create a reflection back to the amplifier... :-;

[Cal Weldon]

Hi moley. Boy that seems rather dear for cabling. Are you wanting to use the flat wire so you can place them under the carpet?

[cyclotronguy]

Not that you asked:

Back in the day a number of amps were known to go up in flames when presented with capacitive speaker cables. Might be worth investigation before you go too far.

Cyclotronguy

[dantheman]

You can buy flatwire and solid, not stranded, speaker cable at Fry's for pretty much the same cost as normal speaker wire. Might not be a bad idea to try that first. Its jacket is paintable. If I remember correctly, you'd have to fold them in half lengthwise to really make a capacitoresque wire out of them, but it could easily be done. I think they even come with a sticky side to make it easy.

Dan