Yamaha DTXpress/DTXplorer/DTXtreme

--- In DTXpress@yahoogroups.com, "Keith" <keith@...> wrote:
>
> Jeff,
> 
> If it is the speed of the pulse then you need to try adding some
> capacitance to the output (transistor collector).  If the rock band
> input impedance is 10k ohms then something like 1uF on the output
> (collector) to ground is worth a try.  It is a bit of guesswork but
> 100nF to 10uF is the likely range that would work.  Too high and it
> will stop working altogether (the capacitor will stop the output being
> pulled down).  Too low and it will have no effect.
> 
> Keith.
>
 
Thanks for the info Keith.  I'll give that a try as soon as I get the 
parts.  I'll assume the cap goes in series from the collector.  I also 
verified that the ground coming out of the RB kit is actually a ground 
(connected to the USB ground) with zero impedance on it.  Your circuit 
works rather well as long as I give the KP65 a pretty hard kick.  
Although once in a while it will miss a kick in a series when hitting 
at the same force.  The only thing I can think of is that the piezo is 
dropping below the trigger voltage before the RB controller can 
register the kick but again it is just a guess.  If I get well tuned 
circuit I'll post it up here.