My build - the mini megadrum

[christian.j.king]

Hi, my megadrum goal is to create a somewhat small module that can be used with a variety of piezo instruments I hope to build that will connect through breakout boxes or directly through IDC. I am new to DIY electronics and am going to be asking some laughably basic questions, please forgive my ignorance; I'm trying to learn.

I'm still in the planning stage but would like to prototype some ideas and I temporarily mounted my megadrum kit into a small Avon cardboard box.

Here's the box:
https://drive.google.com/file/d/0ByyCR6q_2pL3UWZZR0szMWsyXzA/edit?usp=sharing

My first question is: How do I ground this? Should I bolt it to a grounding wire in the box?

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I'm still working on my drums. I've purchased some very inexpensive kids' size drum kits off of craigslist, split them in half, and started hand-stitching the mesh heads. I've used two strips of mesh to cradle the piezo element in the center of the head; the piezo is glued to a soup can lid to increase surface area and separated from the head by a foam cube. I have had varying success in maximizing sensitivity while avoiding super-sensitive hot spots. Any suggestions/criticism?

images:
https://drive.google.com/file/d/0ByyCR6q_2pL3OVNDcmw4Q0FGSms/edit?usp=sharing
https://drive.google.com/file/d/0ByyCR6q_2pL3akhLY2pvSjlNSHc/edit?usp=sharing

video test 1:
https://drive.google.com/file/d/0ByyCR6q_2pL3cE9CREo3Zlg0cW8/edit?usp=sharing

PS - Thank you Dmitri!

[dmitri]

By grounding do you mean earth? You don't need to do this, there is no high voltage anywhere in MegaDrum.

[airflamesred]

Welcome. Is that a cardboard box?

[christian.j.king]

Thanks! I had read about grounding issues but I think that was more in reference to the triggers than the module.

[christian.j.king]

Thanks!

Yeah, it's a cardboard box. I have designs for a finger drum thing, full kit, and a playable mouse-onesie (yeah, you read that right); so, I'm trying to make this as small and light as possible. I also have a 19" rack mount that ties it in with my recording setup, hacked MPD24, and breakout board.

https://drive.google.com/file/d/0ByyCR6q_2pL3Wm9hSDFSOXpwVW8/edit?usp=sharing

https://drive.google.com/file/d/0ByyCR6q_2pL3YWxoWGZOY2c1b00/edit?usp=sharing

[christian.j.king]

I love my megadrum; thank you, dmitri. I'm having an issue that I'm sure is a grounding mistake on my part. I am using the megadrum with abelton live and I keep getting double midi notes when I use a single drum. I've tried using the megadrum manager to fix this; but, everytime I change a note value, the change applies to all the drums, even when I don't apply to all intentionally. I have looked into it and tried the ground of each drum on 15, 16, 15-16, and 40 because I've found different documentation in different places, nothing really helps. Any ideas on what I'm doing wrong? The intervals between double midi notes isn't even constant; so, I really am not sure what's wrong... possibly a megadrum manager setting or method that I'm not utilizing correctly?

Thank you,
Christian

PS: I've been creating a prototype for my guitar bikini hand drum instrument for my mini megadrum.. here are some pics
https://docs.google.com/file/d/0ByyCR6q_2pL3b2Y2cVVleUx2LTA/edit
https://drive.google.com/file/d/0ByyCR6q_2pL3Zld6N3l3Z19RblE/edit?usp=sharing
https://drive.google.com/file/d/0ByyCR6q_2pL3RzhiUENnQnhsZjQ/edit?usp=sharing

[dmitri]

I love my megadrum; thank you, dmitri. I'm having an issue that I'm sure is a grounding mistake on my part. I am using the megadrum with abelton live and I keep getting double midi notes when I use a single drum.

Describe your pad, make a screenshot of all your settings on the input and make a screenshot of the MIDI Log showing double triggering on the input.

I've tried using the megadrum manager to fix this; but, everytime I change a note value

Why are you changing Note to eliminate double triggering? You really should adjust Threshold, DynTime, DynLevel and in worst case Retrigger.

, the change applies to all the drums, even when I don't apply to all intentionally.

Describe what you do in step-by-step for me to reproduce the problem and if it is a bug in MDM, I will fix it.

I have looked into it and tried the ground of each drum on 15, 16, 15-16, and 40 because I've found different documentation in different places, nothing really helps.

Pinout of MegaDrum kits is described in a single place - "MegaDrum kit instruction manual" in viewtopic.php?f=3&t=1420 - which clearly shows that ground is on pins 15 and 16. Where did you get ground on pin 40?

[christian.j.king]

Thanks! I'll get on it this weekend and post a more descriptive reply.

I think where I found pin 40 was on a schematic from 2008; I probably got confused after hours of frustrating troubleshooting and research.

Thanks again,
Christian

[christian.j.king]

Okay, so I've spent the better part of a day troubleshooting and reading the documentation. So far, I've discovered:

Every time I try to sync the megadrum manager and the megadrum, I get a SysEx Timeouts alert and it does not seem to update.

I get midi from most of my inputs except some like 33 (snare H), which I still have not been able to figure out why. I am trying to stay with the pre-assigned input names but I can't figure out if they are not passing midi because of the settings or a wiring issue. Right now, I'm using bare wire with insulated european-style terminals; so, troubleshooting is much easier. Since the settings don't seem to have any affect whatsoever, I'm not sure what the issue is.

The double triggering is consistent for all the triggers but their intervals seem random.

Changing settings on the megadrum itself is helpful but has not fixed the double triggering and I would like to be able to send them to the computer for friendlier editing.

Obviously, I'm ignorant when it comes to this. I am sure that I'm oblivious and making some silly errors. I certainly amazed by how the megadrum is so much more sensitive than my old Alesis DM5 right "out of the box." Rolls are amazing and my soft playing style is treated well by this great product. I just want to overcome this learning curve so that my megadrum knowledge can catch up to my musical and piezo-electric knowledge.

Thanks again for any and all help!

Here are some screenshots that might help:
https://drive.google.com/file/d/0ByyCR6q_2pL3Qk0ycURYYmdYTFU/edit?usp=sharing
https://drive.google.com/file/d/0ByyCR6q_2pL3dmVvYkhUc3lOMDA/edit?usp=sharing

[dmitri]

Every time I try to sync the megadrum manager and the megadrum, I get a SysEx Timeouts alert and it does not seem to update.

Does MDM show 'FW version' in green? If not, then either you selected wrong ports in Options or you have some other program running which is trying to access the same MIDI ports.