2. cables
  3. 128414-84541

Please assure me I'm not going to burn my house down.

I recently bought some new mono class D amps to replace a stereo class D. I had a pair of identical diy power cords connected to the stereo amp and my preamp.

Well, with monos I was obviously going to use the identical power cords. So I needed a new PC for my pre, as the older diy version I had laying around just used thhn wire from Lowe’s and didn’t sound great. So, after some thought and research, I decided to make a PC out of cat 5 plenum cable. I kept it in its blue sleeve (containing 4 twisted pairs) and then I braided 3 lengths together for each conductor. I then took those three braids and braided them. What I have sounds incredible and I’m fairly confident that it is safe electrically.

Please reassure me. Or tell me I forgot about x, and that I should cease and desist. Or laugh at how cheap I am...

But really, I’m not going to start a fire here, am I? 8 conductors per length x 3 lengths for each conductor equals 24 strands of 24awg. Which equals 10awg for each conductor...
128x128toddverrone
tom_hankins
928 posts
 
www.signalcable.com as low as $49. I have zero affiliation with them, other than buying a couple. Save yourself the headaches for a few bucks.
alpha_gt
155 posts
 
Please use a standard IEC power cord until you can buy or make a proper power cable. While the copper in the CAT 5 may be up to the task, the insulation most certainly is not. Way too thin for the amount of current flowing through a 120v 60Hz power cord. 

Nothing wrong with a home made cable, as long as the cable you choose is made for the voltage and current you are using.  That's why regular power cords have that thick rubber coating on each wire, with a thick rubber coating over all conductors. It is rated for household current. CAT 5 is not. CAT 5 can be brittle and break from too much bending, it's rather fragile compared to a stranded copper wire used in an IEC power cable. A custom cable may sound better, but a standard UL approved wire won't destroy your sound either. It'll be fine until you get a proper cable. 
bigkidz
3,381 posts
 
I'd keep the local fire departments number on speed dial for sure!  Maybe go down there and get a few firefighters cell phone numbers also!  Go to the local hardware store and get a few fire extinguishers on hand and a large bottle of water laying around.  Make sure you have access to the main fuse box to cut the power to your home electric when the smoke and flames start billowing up to the ceiling.  Other than that, I think you are fine.

Happy Fire extinguishing Blaze!
 
terry9
2,333 posts
 
I would be most concerned about termination. It is easy to braid wire together - and it's easy for wire to become unbraided at the termination. If the wire does unravel, then you may find one or two conductors carrying all the current. Then things unravel.

Second problem is teflon. If things unravel, those few conductors are going to get hot. If teflon gets hotter than about 500 F, things go badly wrong - it decomposes into highly toxic gases, including HF. You don't want to risk HF. Really, you don't.
toddverrone's avatar
toddverrone OP
840 posts
 
@terry9 the cable is well terminated. I stripped the individual wires and crimped spades at the end of each bundle. I then put heat shrink up over any bit of exposed metal, other than the spade. These babies are solidly terminated.

As for the Teflon melting, that will obviously not be a problem with all the conductors functioning, which they will be. 

Great points, though.

So far, I've not really heard any valid reasons backed by theory, other than @erik_squires suggestion that the insulation may not be up to the task..
More to discover