The DKDI-21 expander is a simple electronic interface which allows the expansion
of the number of inputs on the Yamaha DTXpress I, II and III drum modules.
It has also found many uses with Roland modules and users making their own dual piezo
DIY drums & cymbals.
Anywhere where you have a dual piezo but need it to be piezo/switch type for the
This site is not affiliated with Yamaha (or Roland).
I have finally stopped making the DTXpander PCBs. While I have quite a lot for people
over the years, demand is now quite small and after completing the latest batch it
isn’t economical to make any more. I will still do my best to assist people making
their own where I can.