Yamaha DTXpress/DTXplorer/DTXtreme

I have been experimenting with the DTXpander/"Magic box" with a
Pintech Concertcast snare on my Yamaha DTXpress.  One problem I
noticed was that it wouldn't respond to a small hit after a very
strong hit when using the box.  I tracked the problem down to the
series diode, D3, in the DTXpander, which has an optional jumper on
it.  With the diode shorted out, it works fine.  What seems to be
happening is the positive pulse caused by the diode charges up an AC
coupling capacitor in the DTXpress and that takes time to discharge
(presumably through R3).  Reducing R3 may also help, but I haven't
tried it.  Shorting the diode works well.

I thought I would post this information in case anyone else has had
the same problem.

Keith.