A to E drum conversion : Megadrum + Acoustic drum + Junxion

[kimouette]

Your pot is used for your pedal and is wired tip/sleeve and connected to the hihat pedal input on the MegaDrum. The MegaDrum will then use that to generate CC4 data. That's completely separate from anything else on a hardware level.

Does the following image represent the right way of connecting the whole thing? (if so, that would mean that the "ring" remains unused)

potentiometer-question.jpg

So if you build a 3 zone cymbal, lets say Yahama style, and connect to MegaDrum the MegaDrum will be able to do the following:

Zone1: open note, closed note (lets say this is the bow)
Zone2: open note, closed note (lets say this is the edge)
Zone3: single constant note (lets say this is the bell)

Does choosing that setting involve 1 piezo (zone 3) and 2 more piezos (one for each switch)?

If so, I guess I'll have to wire the chokes like the following image is showing but TWICE (one for the bow + one for the edge)

singlechoke.jpg

And finally, is the piezo located right under the top switch?

[gastric]

For the slider you're way off. You need 2 wires only, positive/negative, wired tip-ring. Since there's more than 2 posts on the slider you need to determine which is positive and which is negative with a multimeter or reading the data sheet for the slider you bought. Usually the positive and negative are on the same end of the slider, at least for those that I've purchased. One end will have 0ohm the other 25kohm depending on which end the switch is located. That's how you determine which end to solder to and how to physically orient the slider.

To start just wire a single piezo on the bow of your cymbal tip-ring and ignore the sleeve. Stick the piezo about 1/3 back from the edge. Enjoy having a working cymbal for a while before you wire in additional zones. Baby steps.

I suggest reading here: http://derksens.com/Beatnik_mirror.htm It covers the standard build techniques in a simple and well documented fashion with good photos.

[kimouette]

Gastric thanks for the clarification about the potentiometer! That's not a problem anymore.

Unfortunately I cant do whatever I want, whenever I feel like it! I depend on someone who owns a soldering kit, a multimeter, a "solder-sucker", and great advices!
So "Baby steps"... yes I wish I could, but at this point I need to be prepared in terms of jacks (male+ female) cables and switch material, and manage to make the whole project fit with my friend's schedule : I have to wait about 2 weeks between each visit!

I did read a lot during the last two weeks (thanks for your references!) to make sure I understood the basics of choke,switch triggers, but I still have questions that I know I will have to face real soon (probably this coming saturday).

So like I already mentionned, I have chosen the following setting :
Zone1: open note, closed note (bow piezo/switch)
Zone2: open note, closed note (edge piezo/switch)
Zone3: single constant note (bell simple piezo)

I looked at Sarge's choke switch and I noticed that the piezo was standing in a box...

Does the piezo have to be 100% isolated from any vibration or could I just stick it somewhere underneath the cymbal? In other words, is there any way to avoid building boxes just for the piezos?

What are the advantages or inconvenients in using Sarge's switch compared to Hellfire's or Cheapthrill's?

And finally, could you confirm that Beatnik's wiring diagram (see picture) is the one and only diagram to follow in order to wire the setting I chose correctly? If so, then I'll need only one Jack for my 2 switches and one extra jack for my bell piezo right?

diagram.gif

[gastric]

What are the advantages or inconvenients in using Sarge's switch compared to Hellfire's or Cheapthrill's?

Functionaly they're identical. You're creating a "film switch" using aluminum. Hellfire uses two pieces of flashing with a thin plastic separator to keep the two pieces from touching. Strike or squeeze the switch, the two pieces touch, the circuit is created, and viola! Let go, they spring back to their original, open circuit form. It's an extremely simple switch design. Sarge improved on it by using his acoustic cymbal as 1/2 of the switch, thus negating the need for 2 pieces of aluminum. I've done both methods for use with a grab choke (never used nor tested for edge hits since my Trigger IO doesn't support that) and they both work, Sarge's improvement is simply a time saver. But it only works with metal (acoustic) cymbals, and you have to have a screw in the cymbal or some other way to make contact with the cymbal itself so it can be used electrically for 1/2 of the switch. CheapThrill's is the same just on top of the cymbal which is easier to strike with the stick. Supposedly Sarge's, though under the cymbal edge, works too. But I'm assuming you have to really whack the cymbal, or have a thin cymbal that can flex under the strike so the cymbal can bend and touch the aluminum flashing.

The absolute best and most robust method for you to build a cymbal for use with your MegaDrum would be to use the 3-zone Yahama style. I'm speaking theoretically as I have not yet done this myself. But plan to.

It uses one piezo, and two switches, all wired to a single TRS jack. And can provide bell, bow, edge, and choke. It provides the most functionality using the least components and does it all while providing the best isolation (no crosstalk) since it uses a single piezo.

* Piezo goes on bow of cymbal, probably about 1/2 to 1/3 back from the cymbal edge, wired to Tip-Sleeve.
* Hellfire-type switch goes on playing surface along cymbal edge, wired to Ring-Sleeve with a 10K resistor. Strike it with stick to generate edge hit, grab it to generate choke. MegaDrum processes the strike VS grab intelligently to generate 2 different events using the same physical switch.
* Hellfire-type switch goes on the playing surface of the bell, wired to Ring-Sleeve, no resistor.
* The box you see is simply to provide protection to the piezo, jack wiring, and to provide something solid to install the jack into. You can put the jack on the cymbal, on the cymbal stand, or use no box at all. But without a box your piezo is exposed (not a real problem if the cymbal sits on the stand for all eternity), and you'll have to run your wires to the jack somehow. Or use no jack at all and just run the wires all the way to the MegaDrum plug, and connect them to the MegaDrum.

That's it. I'd probably just build all my cymbals that way and be done with it. The only disadvantage is that the surface mounted switches likely don't feel as good as a pure acoustical cymbal surface. But purely from a functional standpoint it'll provide the most functionality possible.

Here's the Yamaha cymbal schematic. viewtopic.php?p=3878#p3878

More general details and discussions on the Yamaha support viewtopic.php?f=3&t=293&start=10&st=0&sk=t&sd=a

I can say that building the triggers is a LOT easier than building a MegaDrum. The components are larger and easier to work with. The soldering is all soldering wires to posts, or maybe soldering 2 wires together. You could even use telecom crimps to join the wires if you wanted. All I am saying it's the triggers themselves is a great way to cut your teeth on soldering and understanding simple electronics (piezos, switches, positive, negative, a circuit, etc.) I've built a full 5 piece e-kit, another snare, and then another full 7-piece kit as you can see here: http://www.vdrums.com/forum/showthread.php?t=42514

I've spent far more time trying to build my MegaDrum that it took to convert my entire 7-piece kit to an e-kit.

[johnvpr]

i've tried this wiring but I cant get it to work right!

the only way to se a small change is to set param low to 171 and high to 172

[gastric]

As I said before you don't wire the slider pot like that. Most likely you wire the top 2 posts Tip-Sleeve, and it probably doesn't matter which post goes to the tip/sleeve. That's it, no third wire. You'll need to figure out how to orientate it (which end of the slider goes up) so it generates open/closed properly.

[kimouette]

Are there any chances that the bitumen tape under my cymbales and both hats will take off some of the choke's sensitivity?

[gastric]

Not if you build a Hellfire style switch and mount it to the TOP of the cymbal. You'll be hitting the switch directly with your stick so there's cymbal dampening won't have any affect.

[johnvpr]

I' have connected the Tip and Sleeve and I have between 0 (closed) and 11K(open) but I cant figure how to configure the MD. anyone can sugest me some configuration in MD?

Thanks

John

[dmitri]

As far as I can judge from the pics your top and middle tips of the potentiometer are misplaced. The slider tip has to go to the HiHat input and the top tip has to go to the HiHat power source.