Hey Pete -do you mean to say that a Varitone bucks hum on single coil guitars? I've been real curious about dummy coils too, very few guitars use them, and look at the Gibson Hawk series: a Varitone AND a dummy coil on one guitar... The Qfilter is an LCR network too by the way! That's why i thought there might be some simliarity when I learrnt that Varitones use an inductor.