#1
what exactly is a ring modulator?

also is that the effect heard in the intro on David Bowie's "Kooks" from the Hunky Dory album? or what is that?
#3
Its apparently what Iommi used in the solo of paranoid to give it that edge. But arent many companies who make em. Last 1 I saw was 250 bucks. Theres one in my MFX pedal but doesnt have any usable settings. The moog one has a bunch of knobs so would take a little bit of time to figure out.