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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
pbnaudio's avatar
pbnaudio
1,534 posts
 
Here’s a test for you - go to Home Depot and buy what ever length of cord you need replace your CAT5 cable with this
http://m.homedepot.com/p/Southwire-10-3-SOOW-Black-600V-By-the-Foot-55809799/204632922
Its 10 gauge too so you will compare apples to apples, then let us know if you - truly - hear any difference. This wire is designed for what you use it for.

Good listening

Peter
ericsch
180 posts
 
As a retired insurance manager, I can tell you that only intentionally set fires are denied, i.e. arson. There is no exclusion for stupidity. For example, you leave a frying pan unattended on the burner, house catches fire, covered loss.

terry9
931 posts
 
To address your point about 24 x 0.6 ~ 15 (amps), and braiding together,  the current carrying capacity of multiples depends on their exact physical relationship. That is, if insulated wires are close together, they will not be able to radiate heat as efficiently as if they were separated. Then wires might get hot. Hot (copper) conductors have higher resistance. This has the potential to create a positive feedback loop, and we are back to the potential for HF.

joeylawn36111
574 posts
 
How much current does each monoblock pull? (on the rear of the amp somewhere it will say "120V xxxW" W being the power in watts the power supply pulls at maximum draw, not the rated speaker power output.) Then divide watts by 120 to get the current draw.

Also, there's the fuse rating of each monoblock. Let's say it's 8 Amps. Then you can use wire that's rated slightly higher than that, say 10 Amps. 14-Gauge wire is rated at 15A, so this would be about the minimum gauge for this example.

I can't guarantee that you won't have problems with your homemade PC, but if your wire is well-terminated (won't come loose/disconnected), and doesn't run hot, I don't see a problem with it. But if it gets moved around much/bent, some of the small wires of the CAT cable could break, which would put more heat strain on the remaining wires because they're still connected, and the same current has to go through less wires.

Like was said above, the ideal thing is to get some proper power cord to be sure.
steakster
720 posts
 
Yes, calculations and specs must be factored.  Terry9 nailed the concern about quality of the insulation and the quality of the mechanical wire connections.  Have you ever felt a really cheap extension cord that was carrying a large electrical load over an extended period of time?  The insulation is warm to the touch.  If the load is beyond the cord's safety specs, it is actually hot to the touch.  A serious safety hazard is imminent!   You can try the same thing with your DIY pc's.   A simple un-scientific test is to create as much load on the pc's as possible by pushing the amps to play loud, dynamic passages for a while.   Are they warm to the touch?  If so, dump them.  They should be room temperature.
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