Original poster: "Richard Modistach" <hambone-at-dodo-dot-com.au> hi all, i know stacking 2 nst's to double the amperage is common and standard practice. what's the story with stacking 3 or 4 nst's ive got accses to 4x11\100s and it would be nice to stack them up to 400ma for a larger coil down the track or are the problems going to be more than the headache is worth. regards richard