Preparation buying the MegaDrum, and other questions

[stefan1982]

Hi all,

I'm planning on buying the 56-input Megadrum with PS-board, with the fastest main PCB.
All in all, an excellent decision imo, although - no offense - the case it comes with is quite standard.

While I am going to buy the fully soldered version (i think that would suit me best), I really would like to know what else to expect talking about buying components which are not included.
Are the 6.3mm input jacks already soldered too?
And how could there be 56 inputs, while I count only 26 jack inputs on the back of the interface?

Reading through the schematics page it's saying that the 2 rotary encoders and the MIDI in/out are optional.
What is the _exact_ meaning of the rotary encoders? They could be normal switches too, right? (I'm missing the schematics for this somewhere?)
An how could the MIDI in/out be optional? Is the MIDI data being transferred through USB? Which way of transferring is preferrably? MIDI I/O or USB?

Now, after having tested the interface I'm planning on building my own case of aluminum and acrylic glass.
I would love to remove the normal 5 buttons (on/off, left/right/up/down) with some capacitive touch switches, although I'm not sure how to do that as it seems to need power.

I hope some people are willing to answer some - if not all - of the questions on this post.
It would be _really_ appreciated!

[airflamesred]

Some answers,
56 refers to mono inputs. If you use 2 piezos or piezo/swich you would use 2 inputs. Depends on what you want to plug in to it.

The full kit from Dmitri only needs a case and jack sockets which you need to solder to the leads from the main board. Once again mono or stereo jacks depending on your needs.

Midi goes via the midi sockets and the USB - If your connecting to PC then you'll only need the USB.

As far as the front panel goes, I don't touch mine at all. I do all the tweaking from MDM.

[stefan1982]

Nobody had any idea about the capacitive touch buttons?
Is it possible?

[airflamesred]

Nobody had any idea about the capacitive touch buttons?
Is it possible?

I shall have to defer to Dmitri on this. As I say, generally you won't use the front panel.

[dmitri]

The 4 pins buttons input on the board has 3 input signal pins and 1 ground pin. Depending on the combination of signals on these inputs MegaDrum figures out which button (or a combination of buttons) is pressed. 3 pins can give 8 possible values (combinations) which MegaDrum can read from them (2^3). 1 of these values (7 for all highs)means 'nothing pressed', 1 - for LEFT, 1 - for UP, 1 - for DOWN, 1 - for RIGHT(in fact UP and DOWN at the same time), 1 - for LEFT+UP, 1 - for LEFT+DOWN, 1 - for LEFT+RIGHT(in fact all buttons pressed). You can design your own buttons device based on this. Don't feed more than 3.3V to these pins.

[stefan1982]

You can design your own buttons device based on this. Don't feed more than 3.3V to these pins.

That means that the capacitive touch buttons are not going to work. According to specs of the PCB Gadgets Round Capacitice Touch Switch it seems to need 5.5V.

Specs

• Capacitive switch available in toggle or momentary mode.
• Switches a max 3 A load current. (New higher amps rating).
• Senses through an overlay with 4.5mm (0.180">
• Wide input voltage supply ranging from 5.5v to 23v.
• Provision to attach an external sensor to increase sensitivity (see datasheet).
• Board size is 1" in diameter.

And, besides that... I have no clue how to wire that, according to the post of Dmitri.

[dmitri]

You'd better not to do this if you don't know how to reduce voltage or do wiring.
Aren't you over engineering it? As you were advised, it is much easier to configure MegaDrum from a PC using MDM rather than using buttons/rotary encoders.

[stefan1982]

Perhaps you are right Dmitri..

I think I'm going to forget about all the (rotary) buttons, and only do the on/off switch as a capacitive switch with a custom acrylic project box.
That should do the trick I think.
Iwasn't aware of the fact that the MDm made the complete buttons and LCD display absolete.

Thank you for your precious time and effort. I'll contact you shortly for buying one of the kits.

One question though, the hi-hat pedal input switch. What does it do besides switching between pin 3 and 5 from the pads connector, and could it be removed? What purpose does it have? When to use low, and when to use high?


Thanks in advance.

[dmitri]

One question though, the hi-hat pedal input switch. What does it do besides switching between pin 3 and 5 from the pads connector, and could it be removed? What purpose does it have?

Just to switch between low and high impedance pedal inputs. You can remove the switch but then you'll have to solder two pedal input jacks to be able to choose the pedal input which best matches your pedal.

When to use low, and when to use high?

It depends on if a pedal is low or high impedance type.

[stefan1982]

Is it fair to say that for example a Yamaha is low impedance and Roland cymbals are high impedance?