OK on all that Al and the IXDD414CI mention.
I think that my rig is a first in that few now build VTTCs and when they did,
musical modulation was not popular until SSTCs were built.
Of the many coils I have seen running on the web, VTTCs, none use modulated sparking for music, only plasma producing the non bass stuff.
That is what I first started building for, but changed horses ( or sparks
) in mid stream and wound a new coil.
I wouldn't put my laptop anywhere near or connect it, when the sparks fly!. Only a cheap portable CD player. I don't know what the possibility is of a flash over from the GU81 anodes to the centre tapped filament but so far all has run OK.........….Beginners luck?
Of all the many interests I have had and have, this sparky lark is the most
dangerous of all, but so, so intriguing.