DIY piezo wiring

[bcslaam]

Hi all, happy xmas!

I am still a little unclear as to:

1) How to diagnose if my piezos are too hot and require a resistor or variable pot. What are the tell tale signs? Putting gain at zero gives a usable range of sensitivity but there's double triggering, excessive xtalk and no middle dynamics, level always quickly jumps to max no matter what curve I use.

2) I've read dmitri say that put the resistor/pot inline with the centre wire. All my drums have rim sensor so would this require a pot for each peizo? Or can I wire it like this



EDIT: THIS DIAGRAM IS CONFIRMED AS INCORRECT BY DMITRI. READ ON.

my 50k pots have 3 terminals like this and it would save me a little work and money if this were possible. I have snare with PS and toms that Im not fussed about PS yet, can they both be wired as above? Seems like this wiring may bridge rim and centre piezo though I am not sure.

Cheers

[airflamesred]

If you reach hi level very easily then your pads are too hot. I'd be tempted to look at changing how he piezos are mounted (perhaps some damping) in the drums rather than cooling the signal.
In fact reading your post again, post a pic showing how the piezos are mounted.

[bcslaam]

The other thing was I read airflamesreds piezo behaviour was improved by "deadening" by dmitri.

How would one deaden both the centre piezo under the cone and the rim piezo stuck to the shell?

For shell would you rip it off the existing double sided tape and put another layer of db sided tape? Currently my metal disk of piezo is touching the shell either side beyond the one layer of db sided tape due to the curve of the shell. Should I be raising it with db tape so that it doesnt touch the wood?

What are the other types/methods of deadening? Tape over the piezo strapped to shell or cross bar? To save trial and error what are your ways of deadening in small amounts to achieve good results and to not have to rip off the cone from its tape and risk damaging it for example.

Cheers.

PS: Thanks airflamesred I will take a pic and post

[bcslaam]

OK so this rim closeup is of my 14" snare. With my 10" tom the radius is smaller thus the problem possibly worse.

[bcslaam]

Any comment on the piezo wiring to utilize one pot for both piezos? The diagram was from this thread

http://www.vdrums.com/forum/advanced/di ... 1207617052

[airflamesred]

For the rim I used blue tack but you can (and should) use double sided foam tape.

As I understand for the head, the distance between the cone and head is the important thing (As they touch, this is a sort of negative distance) so try adjusting the height. What high level reading are you currently getting?

[ignotus]

I don't think you can wire two piezos through the same pot - the module wouldn't be able to know what piezo was triggered. The way I wire mine is: ceramic -> pin 1; pin 2 -> jack input (tip or ring); pin 3 -> sleeve (ground).

I use trimpots (instead of regular "large" pots) in all my pads. I also find that with some pads, even though I get a highlevel of, say, 700, the mid-range dynamics just aren't good, in addition to the other issues you describe (double triggering, etc), no matter what settings I use. Trimpots are cheap, and once installed in the pad they give you an extra level of control over its output. In some cases they're just left open and in others they've considerably improved the triggering and I couldn't do without them. It's easier, more effective and gives you more control than trying to "deaden" the piezo physically, where you keep having to go through trial and error to reach an elusive "sweet spot". The trimpot gives you a gradual and continuous sweep from "open" to "dead".

As for rim piezos, one way to avoid the curve of the shell is to use a small angle bracket. Screw it on with a lug screw and then stick the piezo on the angle bracket. Another is to use a big dollop of hot glue. My snare has it this way - the problem is that if you have to remove the piezo you'll destroy it, though mine has been there for 9 years and I haven't needed to touch it.

[airflamesred]

In some cases they're just left open and in others they've considerably improved the triggering and I couldn't do without them. It's easier, more effective and gives you more control than trying to "deaden" the piezo physically, where you keep having to go through trial and error to reach an elusive "sweet spot". The trimpot gives you a gradual and continuous sweep from "open" to "dead".

Does the trimpot not do the same job as turning the gain down though (if possible) ?

[ignotus]

You might have gain at 0 and a highlevel of 500 - apparently all's fine. But then you see that the velocity goes from, say, 30 to 90-127 too easily, skipping all the mid-range velocities, no matter what curve you use, and if you set highlevel to 600 it maxes out at a velocity of 100 or 110. With a trimpot you can get back all that mid range and adjust your gain so you can have a highlevel of 800 if you want. You also have to find the sweet spot but it's easier to turn a trimpot than to mess around trying to physically dampen a piezo by "exactly" the right amount.

[airflamesred]

You also have to find the sweet spot but it's easier to turn a trimpot than to mess around trying to physically dampen a piezo by "exactly" the right amount.

Yes, of course, and don't doubt you for one minute Ignotus. Looks like I may have been labouring under an illusion with this one.
Thanks