I've made several cables, and wired a few amps using my favorite (Cardas) wire, and here's how I do it.
I fan the wire out, lay it flat on my table, and use an Xacto knife to gently scrape the enamel off one side, then flip it over and do the other side.
Then I twist the wire together back together, put a bit of Cardas paste flux on the freshley scraped part, and apply heat from my iron.
Next, I apply a generous amount of solder and leave the iron on it to burn off the remaining enamel (Cardas uses Teflon sleeving so it doesn't shrink back
too much). Then I use the iron tip to wipe off the excess solder and burned off enamel. I should mention that I have my iron turned up quite high.
Labor intensive, but I feel that it is worth it. BTW, as far as I know, the Cardas #24 chassis wire is the same wire that's in the 4 x 24 cabling. I've stopped
using the 4 x 24 stuff and just use the chassis wire. I loosely braid it and cover it with multifilament nylon. It's more flexible, and considering how the
price of the 4 x 24 stuff is heading into the stratoshpere, a heck of a lot cheaper. I know that I lose the shielding doing it that way, but I haven't noticed
any problems with hum at all.
FWIW