Yamaha DTXpress/DTXplorer/DTXtreme

Stewart,

This is what I did.

I opened up the TP65S and left the two leads coming from the PCB to 
the pad piezo connected. .

Trial 1: 
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I physically isolated the rubber pad containing the piezo from the 
bottom housing with the PCB and the rim switches.

I wacked the rim switches, one at a time. No sound.

I wacked the pad, and the piezo triggered the snare sound.

Trial 2:
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I then allowed about 1" of the edge of the rubber pad containing the 
piezo touch the bottom housing. So that when I hit the rim switch, 
the piezo should pick up some of the vibration. 

I wacked the pad, and the piezo triggered the snare sound.

I wacked both the rim switches, no sound.

Trial 3:  
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I set the rubber pad almost completely on the housing except for a 
small edge to expose a piece of the rim switch.

I wacked the pad, and the piezo triggered the snare sound.

I wacked the top rim switch, no sound.

Trial 4:
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With the rubber pad sitting on the housing, I used my fingers to tap 
the pad and rim.

If I hit the rim slightly before I hit the pad, no sound.

If I hit the pad slightly before I hit the rim, only the piezo 
triggers the snare sound.

If I hit the pad and the rim at exactly the same time (micro-seconds 
here) only the rim triggers, the top one triggers the cross-stick 
and the bottom triggers the rim-shot.

The moral of the experiment.The piezo and the rim switch have to 
triggered within micro-seconds of each other or the rim will not 
trigger the sound assigned to it.

So if you could create a magic box that could transform the piezo 
signal into a rim closer, you would still need a gizmo to 
simultaneously trigger the piezo in the first pad or at least put a 
strong signal on the tip/sleeve, as well as, on the ring/sleeve, so 
that module is tricked into beleive the two inputs (rim/pad) had 
been struck simultaneously. Because without simultaneous triggering 
the rim input won't produce a sound.

The secret maybe in the physical location of the magic box. It may 
have to go between the module and the pads. And it would provide 
the "smarts" for determining whether to just trigger the pad voice 
or the rim voice (or in the case of the inputs 2,6,7 one of the two 
rim voices.)

In other words the magic box has one stereo output jack that goes to 
the module.

It then has one mono jack to pad1, a mono jack to pad2 (and in the 
case of inputs 2,6,7,  one additional mono jack to a third pad.)

If the MB gets a signal from pad1 then it passes the signal directly 
to the module on the tip/sleeve conductor. If the MB gets a signal 
from pad2, it then sends both a "piezo" and a "rim" switch signal 
simultaneously on the tip/ring/sleeve (and in the case of inputs 
2,6,7, a signal from the third pad would send a different signal 
simultaneously on the tip/ring/sleeve cable to the module.)

This all sounds logical to me now, tomorrow I'm sure I look at it 
and go "Huh???"

Any other suggestions, I game to try it.

OGD