testing pads

[grandpayum]

i'm at work right now but i was able to get a scope so I'll try that out and the loose piezo idea when I get home. I will recheck all joints and wires but I checked continuity as I built as it should be okay but you never know. I would be surprised that every pad built is bad because of joints; I don't mean to sound cocky but I'm pretty good at soldering.

as for the construction of the pad they are acoustic drums with a 6 spoke MDF crossbar with a neoprene coated metal riser for the head piezo, rim piezo is mounted on reverse of crossbar. Here is an image of an open drum before piezo installation: http://i.imgur.com/0Unfd4X.jpg?2 . cone is poron soft layered (4 layers of 1/4" and one layer of 3/8") cut into a cone ~35mm tall with a width of 38mm at the base and 7mm at the top (roland style cone).

edit: tested continuity again, fully open on all. the scope showed a signal though, slightly cooler than the roland pads (0.2v versus 0.5v resolution). Waves were comparable although the rolands were more complex (or possibly noisy). Taken through the cable and at the solder points on the jacks in the drums. Noted that wiring is rim to tip and head to sleeve; in addition i noted the ceramic side is up. would the brass side being down/mounted (with double sided tape) pose an issue? i doubt it but figured i'd ask. the only difference noted with a bare piezo was a slightly hotter signal but I expected that. Still have to try making a piezo only trigger to connect directly to MD. Connected 9vdc to piezo and noted that it emits a click which is expected for the diaphragm to my knowledge. Gonna eat dinner now but can post waveforms later if that would help anyone dx?

[privatex]

Well now everything sounds very complex.
Correct wiring: head to tip and rim to ring (you tried I know...), but I don't know haw you can have problems at this stage. Bad piezos or... we will see
'would the brass side being down/mounted (with double sided tape) pose an issue?'
No that's not a problem...
update: The only thing I can think of now is that maybe you are using a 3pins piezo (piezo with two ceramic areas).

[grandpayum]

Well now everything sounds very complex.
Correct wiring: head to tip and rim to ring (you tried I know...), but I don't know haw you can have problems at this stage. Bad piezos or... we will see
'would the brass side being down/mounted (with double sided tape) pose an issue?'
No that's not a problem.
update: The only thing I can think of now is that maybe you are using a 3pins piezo (piezo with two ceramic areas).

nope, 2 pin. Later today I will attack it more - maybe an issue with patch cables or jacks or something. I guess there's an outside chance that by luck the roland pads were happened to get the good cables/jacks or something?

[privatex]

Try with roland pad and one cable, if it work use same cable and connect single piezo... you know what to do... test piezos,cables, jacks...problem must be in connection

[grandpayum]

Try with roland pad and one cable, if it work use same cable and connect single piezo... you know what to do... test piezos,cables, jacks...problem must be in connection

you are right. i tried roland pad in all jacks and they all work but i noted that it detected no rim shots, head only. Also, I tried just attaching two piezos to a jack and they operated as they should in the midi log and head and rim were differentiated as they should be. The issue has to be with the pads or the cables but I'm scratching my head thinking what I could've screwed up on each pad? I'll tear them apart this week and keep testing

edit: figured it out! at least for one pad. So i was using these ( http://www.mouser.com/Search/ProductDet ... -ACJS-MHDR ) for stereo jacks and i had connected to the wrong side. one set of legs is input and the other set is cut off when a cable is inserted- this is why I had so many misleading tests. As for the rim shot detection with the roland pad i must have messed up a setting because I reflashed the firmware and it works. Thanks for help everyone!! excited to fix the rest and start configuring!

edit2: sure enough, did it on every drum except for kick. I had kick wired with a mono jack that put head to tip and was using a stereo cable though so I've replaced that with a stereo jack with T/R shorted to head and that seems to have solved that issue. Thanks again to all! time to work on cymbals!!

[Elegantdrum]

Long ago, I wired up a Tama pad (1985 simmons type) with 3 pizio's in parallel. The signal was so hot, I blew an input on an alesis D4.

The point being, if you are having a problem with low level, you could put two there and also level out your hot spots by using two in parallel.

The problem is, once you start experimenting like this, don't be surprised when you find your limit by blowing up an input.