Piezo vs. FSR on Sleeve Input

[Guest]

I have been building my own V-drums to go with the TD10 that I just bought. I built them just like the Roland PD-120: A wooden shell, mesh head and a sheet metal bridge across the middle. There's one piezo mounted a platform in the center of the bridge with the foam cone on top, and another piezo glued directly to the bridge, close to the drum shell.

Thankfully, when I plugged it into the snare input on the module, it worked as expected. I get the snare sound when I play the head, and I get the rim shot sound when I strike the rim. (I isolated the center piezo from the bridge a little, so it's easier to get a pure rim trigger than with the PD-120.) Anyway, I tried the other inputs and found that I can trigger the rim sounds on all the other inputs except for Tom 3 and Tom 4.
I've read a lot of posts talking about how the Snare input is the only one that is truly piezo-piezo, while the rest are piezo-FSR. This does not seem to be the case. Obviously, there is some FSR circuitry incorporated to get the choking capability, but I have built all my drums to be dual-piezo (for interchangability) and I now have rim-shot capability on Tom 1 and Tom 2.
(I built 5 dual-piezo toms, so, utilizing another input, I can get 2 sounds out of "Tom 5," as well.)

Maybe I've been misunderstanding a lot of what I've been reading, but it seems like simply wiring in a bridge-mounted piezo to one's PD-100 (or replacing them with PD-120s) would give one the ability to trigger rim sounds on Tom 1 and Tom 2.

The implications are also interesting for people like me who are going the acoustic cymbal route and have all those cymbal inputs to play with.

Thanks in advance for your feedback,
Jason

[clymore]

I would like to see some pictures of those drums. I am interested in building a few myself!

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TD-8, TD-7, Roland rack, Pintech AX14, ConcertCast and Roland PD-9/7/5 pads, Yamaha and Pintech cymbals, Dingbat, Nimrod, Vertikik & KD-7, FD-7 , DrumKat DK-10, Fender Bassman 60.......2000 Eclipse GS

[Boingo]

You're saying you are triggering a rim sound using a stereo cord and dual piezo triggers when plugged into the tom 1 or 2 input? You're saying that the rim trigger light comes on when the rim is struck? You're saying that if you program a tom sound on the pad and a cowbell on the rim that they work separately?

Just want to get this straight because it's contrary to everything I have read on this forum for the past couple years.

[dr. kildrum]

Hmmm. I'll swith the cables of toms 1 and 2 with the cables of toms 3 and 4, so my PD120s are going into 1 and 2 (and I'll change the settings to reflect PD-120s instead of PD-100s and vice-versa), but something tells me that rim light isn't going to light up. I'm almost sure I tried it when I first got my kit. But I'm an eternal optimist, so I'll give it a try unless someone beats me to it.

[Guest]

Boingo,
Yes, I used a TRS-TRS cable with a dual piezo pad, just like a PD-120 and yes, the rim light does come on.

Clymore,
I hope to borrow a digital camera and get some photos on this site once my kit is complete. (Well, no drumkit is ever complete, but you know what I mean.)

Thanks,
Jason

[Guest]

feefer,

That explains why rim sensitivity cannot be adjusted for anything but the snare input.

Here's something to think about and perhaps do some experimentation with: I can't detect any difference between the snare and the toms in the reliability of triggering rimshots. I think this may have to do with the fact that for my drums I mounted the center piezo on a sheet metal plate that straddles two dense foam supports. This isolates the center piezo from vibration when the rim is struck. The isolation is partial, of course, but may be just enough to allow the module to more consistently determine which part of the pad was struck.

I'm operating under the assumption that for a rim shot to sound, the module must detect a signal simultaneously from both piezos, but with the ring-channel signal being some amount greater than the tip-channel signal. (Tinkering with different combinations of triggers with the raw piezos led me to this conclusion. I may be off base, though.)

Thanks for the responses everyone. I've lurked around this site for some time while building my pads and preparing to buy a module. Now that I've taken the plunge I hope I'll be able to add some worthwhile info to this site. I know I've already gleaned a ton.

Jason