Gastric's MegaDrum build

[elrules]

Let me give you a piece of advice. Some of your solder points seem to be cold solder points, they may not contact well. To avoid those type of bad soldering (the solder is like a ball around the lead) let the solder get more heat. THe correct soldering points are the ones similar to a mountain.

Maybe the solder tip has a bit of oxid. For my tip, as it was solid, I sharpened it with a knife sharpener each time it got too oxid. THen the tip starts to work and heat well again

[gastric]

Nearly all of the solder points have mountain-like peaks, but I do see some roundish ones. Though they all still have the appropriate shine and aren't dull and grey as you normally see on cold solder joints. I think it's more of a result of too much solder on the iron where I touched the iron with the solder instead of the component and board, then it clings to the iron when pulling away or sometimes drips off.

Like I said, I have a big clunky iron. And no, I can't file the tip down as it's a cheap coated tip. I tried that while building my edrum conversions and wasted a tip. Like I said, a good quality iron was the only tool I didn't buy and now that I'm almost done I don't plan to. I'll hobble along with my cheap-O for the rest of the project. I just means de-soldering the occasional mess. I also have pretty thick solder which probably doesn't help the accuracy on the small components either. I'm assuming they make it in thinner lines and just used what I had.

[elrules]

If some solder is melted with the surface of the PCB then altough it looks like a ball it must do good contact. If something doesn't work, then you know where to begin checking

[gastric]

I gave a feeble attempt at ironing on the top artwork. Note you have to flip the image Synthex provides for it to match properly if you want to apply it to the board. So I just printed one and used it as a visual reference which is fine.

I have all of the board components installed with the exception of:

* LCD header. Mouser didn't ship me one as best I can tell.
* IDE header. I accidentally only ordered 2 and used them on the jacks board.
* HE-14 header for the MIDI. The JACKS board used a ton of them for the pedal jumpers and I ran out.
* Cable ends to connect to the HE-14 headers.

I still need to construct my ISCP cables as well so I can program the chips. And of course mount everything to the chassis which I don't plan to do until I have the board tested functional.

I used my handy dandy multimeter to check traces and solder points. I found it most helpful to test as I went and to have a printout of the board traces as reference as the solder often hides whether a trace was isolated, grounded, supposed to connect to the adjacent solder point, etc.

Other notes: I ordered a surface mount 47uF but simply bent the leads out and it mounted fine. Some of the components require specific orientation on the board for positive/negative and the components are not clearly labelled with a plus/minus sign so I had to reference the data sheets to confirm. But thankfully the components have some generic identifier to indicate the positive such as a marking, longer lead, odd shape to that side, etc.

[dbreaston]

Is Mega Drum Positionally sensitive?

[elrules]

Is Mega Drum Positionally sensitive?

Not yet , if you are referring to having different midi notes depending on where you hit on the mesh head, as the Roland TD-20 does.

[kimouette]

Gastric,
I noticed that you've put 3 or 4 rim piezos on your snare....
What are the advantages?
and do you connect all your rim piezo to one single jack or multiple jacks?

[gastric]

I wired the rim piezos to the same ring/sleeve on the same jacks. Multiple piezos just provide better and more consistent triggering across the entire rim. If you only use a single piezo the velocity will be loudest around that single piezo.

I'll be adding 1-2 more bow piezos to my ride as it has a hot spot within 2" of the location of the peizo and I'd like to get consistent velocities across the entire playing bow area of the ride. This isn't an issue with the bell since it's a small physical area, nor crashes since you generally just whack them fairly hard as opposed to playing a wide variety of velocities like you do on a ride.

[kimouette]

Since I currently have only one piezo to make some tests, I didn't get to try lots of different settings. But already, I'm disapointed at the snare's lack of naturalism. Hitting the cone directly sure works, but near the rim, and while doing drum rolls, it doesn't sound quite real (even though I used a great snare kit)!

I might just stick extra piezos to each instrument and solder them to the same jack, like you did!
Are you sure the signal doesn't get all "messy" when hitting hard between two or 3 piezos?

[gastric]

Multi-piezos is for the rim ONLY. You still use a single piezo for the head. As far as the sensitivity or overall performance of head hits you are likely to always find that hits directly over the piezo are louder (more velocity) and hits further away are softer (less velocity). I'm not a drummer but from what little experience I do have that seems to jive with acoustic performance. But you should also be able to manage that to some degree via module settings which is out of my realm of experience at this point since I do not have a MegaDrum yet.

If you don't mind just PM me or start your own thread. I was hoping to keep this for my MegaDrum build only.