I received a couple 10 packs when I bought my Brent Sig. They play and sound a bit softer than my usual Slinkys. I did a search and a few posts mentioned they were made by D'Adario spec'd with pure nickel wraps instead of a nickel plated steel. Can anyone verify they're nickel wrapped? A bought a set of SOS nickel strings a few years ago, and the PRS strings do remind me of them.