I have gradually changed and upgraded my system over the years, moving from NAC 92 NAP 90 to my now NAC 82, Supercap, NAP 135s driving SBLs. All the time I have used the same lengths of NAC A5. I was having a poke about the other day… as you do and looking at the wire behind the black sleeving it is very green, verdigris is clearly there, this goes at least 15cm up the cable, probably more, I didn’t look any further. Is this normal and will it be degrading the sound? It can’t be seen unless you look for it but it just doesn’t seem right to me.
This is a quote I just found on the net, can’t comment if it’s accurate but interesting.
“it’s caused because over time and exposure to environmental variables such as temperature, the PVC degrades to form hydrogen chloride as one of the decomposition by-products. The reaction product, copper chloride, is green.”
Yes, that was my thought, but I would have to cut them back so much they would not connect the speakers to the amp!! Sadly, sounds like new cable time. Have you heard of this happening before Richard? Thanks for your advice.
I have heard of it (IIRC there was a post about it on some cables many years ago on one of the old forums) but I’ve never actually ever seen it. I’ve got lots of runs of A5, some vey old indeed, and they look fine.
Interesting. According to Wikipedia, “In a fire, PVC-coated wires can form hydrogen chloride fumes” but says nothing about normal temps. I guess the hydrogen chloride would indeed react with copper to Copper(II) chloride, which looks like this: https://en.wikipedia.org/wiki/Copper(II)_chloride
These effects of metal mixes with different whateveritiscalled occasionally reappear and it’s maybe expected as most people who take any kind of chemistry in school hear about it. And certainly there are situations where it is an important considerations but I am not aware of it ever bearing out in home electronics situations. I remember around the early nineties there were stark warnings against putting RAM with gold connectors into sockets with a different material (forgot what it was) and vice versa. However, in 30 years in the home and business desktop computing industry I never came across an issue from it, and remember to have read an article maybe ten years ago saying that it had been all hogwash, with some chemical reasoning.
Just get new cables. A lot of older designed cables did this. Monster cable was notorious for this. I hate to say this, but this can also happen to internal wiring . I hear a lot of folks here loving the Witch Hat cables might give those a try.
Is the room very humid, or is there damp in the floor or walls in the vicinity of the cable? I have seen corroded copper in a cable that had lain for years along the floor edge, and investigating revealed damp in the wall. Whether that was definitely the cause wasn’t proven, but seemed a possibility, and anyway pointed to some remedial work needed.
Being a plumber and using copper, obviously. I would say that damp has caused this.
Either its got wet at some point, or been in humid air.
It would have crept down from the un shielded ends between the copper and plastic.
Copper goes green, naturally, ever seen a house with a light green roof, thats a copper roof, copper pipe the same, starts of nice and shiny, but soon dulls of, add in condensation on the pipe surface and it will start to go green
Thanks for your thoughts. So you think damp more probable than PVC breaking down, do you think it would have to to have been more than damp in the air in the cooler garage? Thinking about it can’t see how damp would get into the sealed wire. Condensation possibly, but again it is sealed.