>I did a rough block diagram of this. The implementation is
>relatively easy up until you get to the part about eliminating the
>crosstalk. Believe me, I know what you guys are talking about. I
>have a set of V-Drums.
>
>The crosstalk issue could be dealt with one of two ways. You could
>compare the peak level of all four triggers and only allow the
>largest, or you could compare the timing of the triggers and only
>allow the first one. I'm not sure if the propagation delay between
>the pad being triggered for real and the other pads would be long
>enough to make this practical. In fact this is the feature most
>likely to introduce latency.
>
>It's probably worth playing around with this.
>
>I'm thinking you have a very fast envelope follower. As soon as the
>incoming signal reaches a certain level a trigger is generated,
>probably with a schmitt trigger. The follower also drives a peak
>detector. The peak level is the CV. A pot on the input controls
>the sensitivity. A pot on the output of the peak detector controls
>the curve. The trigger drives a gate with a variable on time.
>Thats it for one pad. You do have to decide when to drop the peak
>in preparation for the next peak. Possibly the leading edge of the
>incoming trigger could reset the peak detector.
>
>For four pads you have to either compare each peak to the other
>three and only the largest would generate a gate and trigger. Or
>you have the first trigger recieved lock out the other three for a
>set time interval. It would take some experimentation to determine
>the best method.
>
>Food for thought. How about it Scott. Any way to MUUB this one?
Taking a trigger and converting it to a gate can be done with the
TLN-866 gate processor. But I've never tried it with any kind of
V-drum or piezo trigger, so I can't say if the levels from the drum
pad are hot enough. Of course, you only need to change a couple of
resistors to make it work with smaller signal levels.
It is possible to make a peak detector and crude envelope follower
using MUUBs. But I think if you wanted a really good circuit you'd
have to design a really good circuit and not limit yourself to what
can be built using MUUBs, particularly when you want to minimize
crosstalk. It's definately worth trying.
Wasn't Paul S. going to have an MOTM quality envelope follower this
year? Could it also be used with this type of drum pad?