I recently bought a 682DRUMS ribbon trigger, fitted it, however the piezo is very cool and no matter how high the gain the signal was small. So looking as to how it was made, produced my own. A square of aluminium, mouse mat, ribbon, piezo and home made cones from a yoga block.
They work a treat very little cross-talk, easy to fit, no alteration to the drum. Take off the head replace with a REMO silent stroke lay the ribbon over the rim, position in the middle with the cone 2-3mm above the top of the rim. retain temporarily with tape. Tighten down, fit a 3.5 of 6.4 jack socket through the air hole, solder done.
I made 7 of them in a couple of hours, they have transformed my kit. If anyone needs any more info let me know.