I'm building that circuit, figure it might be the easiest way to go about this... But I'm not sure what the Cb is on the 100nF cap between the +12V and the -12V terminals.
What does Cb mean? I've never seen that designation. Is it just a ceramic disc?
Yes, just a bypass wired across the two power voltage rails placed as close to the op-amp as practical. Any small ceramic cap in any package style is fine. And yes Cb is not a common symbol, maybe it's just an Aussie thing?