MegMalletRex is a DIY 'electronic marimba' project that I started a couple years ago and then shelved due to a fairly serious injury. I have been progressing with recovery from a surgical procedure which has sorted things out, mostly. It has been a long road, but I'm finally to the point of dusting off this build and pushing it across the finish line.
The name comes from Mega in MegaDrum, Mallet (for obvious reasons), and Rex because it is constructed mostly of Bosch Rexroth Structural Aluminum framing. Presently it is a little over an octave. The bars are 22.5mm thick 40mm wide and 120mm long.
KeyBar22.5x45.jpg
The piezo is attached to the bottom of the bar with adhesive and wired through a hole drilled in the bottom of the bar to a 1/4" jack which slides into the hole at the bar end. The striking surface is a quarter inch thick pad which very much resembles the material used for mouse pads from the 90's. Today it is sold as a drum muffling practice pad. I got a few and cut them up.
I have changed up the design a bit from the previous approach. I am still using Marimba cording to mount the bars and reduce cross talk, but I am running it lengthwise through the channel on each side of the bar rather than through the bar. Basically this avoids more machining of the bar and doesn't interfere with the internal wiring as the previous approach did.
I am using the 56 input MegaDrum which will "read" the impact of the stick on the bar, and then send a message over MIDI to Native Instruments Komplete running on a PC, or a Roland HPD-15, for sound generation.
If I were doing this commercially, I would most certainly NOT use a MegaDrum56. That would be silly. No disrespect to Dimitri who provides a fine product and service this community, but the full MD56 is just bigger than necessary for this sort of project. Frankly, most of the size of the MD is to have space for the 1/4" jacks. If you didn't need those, then you could put it in a VHS tape size form factor. I'd get Dimitri's MegaDrum kit and build it into an enclosure designed into the overall structure of the instrument. However, I happen to know that I might feel the urge to repurpose some or all of those inputs at some point, so I use the MD56 to allow more flexibility down the line. By the way, my MD is soooo old, I don't even know what chip is in it. Heck, the firmware is from 2012 at some point I am going to have to upgrade that, but I have to figure out what chipset it is using first, so that I follow the right directions.
Lots to do on this. I'm hoping to make some headway on it this week and next.
If you have further questions, I will do my best to answer them.
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