Building the Megadrum

[japi]

Hi !

I'm kind of lost, i think i will be needing a compass soon The more I read the forum the more confused i get.
As far as a i've read, if one want to build the megadrum, has 3 options:

1) Build the 2 boards, with the schematics from Dmitri that are posted in the home page and the forum here viewtopic.php?f=3&t=266
This aproach has the downside of having to make 2 pcb's and use a lot of diodes (64 bat85). What I don't understand is that Dmitri himself posted a finished megadrum that DOES NOT use this schema. As far I can see in this picture download/file.php?id=666 that board seems an all-in-one . What happened? Is there a finished Megadrum with Dmitri's original 2 board schema?

2) Build the all in one 2.5 by Synthex viewtopic.php?f=3&t=198 . This can be done at home too, and does not use the 64 diodes and is only one board. A possible problem with this is the availability of the schema, as it is provided in gif file and not in kicad, with the risk of having size issues when printing?

3) Purchase the all in one 2.7 from Synthex, this is not intended to be done at home as it is a double layer design viewtopic.php?f=3&t=187 . This is very nice and the only downside could be the delivery time.

Are these statements correct? Please give advice otherwise.

More questions:

a) Is the PCB for 32 inputs mandatory or optional ?
b) Is the firmware the same in all of these 1,2,3 build options?
c) What are the advantages and downsides of each approach besides the ones I've pointed?
d) What aproach 1,2,3 do you recommend?
e) Aproach 2 in the link provided says that the 2.7 is better than 2.5. Can you explain what is better in 2.7 and why?

On a side note: I think the information about the proyect should be arranged a little, there are pieces of information here, another there, and you only discover this information by navigating the forum by hours. This is not a troll just something that I noticed. Again, I congrat the hard working that's being done here.

Thanks a lot
Javier

[dmitri]

Hi !

I'm kind of lost, i think i will be needing a compass soon The more I read the forum the more confused i get.
As far as a i've read, if one want to build the megadrum, has 3 options:

1) Build the 2 boards, with the schematics from Dmitri that are posted in the home page and the forum here viewtopic.php?f=3&t=266
This aproach has the downside of having to make 2 pcb's and use a lot of diodes (64 bat85). What I don't understand is that Dmitri himself posted a finished megadrum that DOES NOT use this schema. As far I can see in this picture download/file.php?id=666 that board seems an all-in-one . What happened? Is there a finished Megadrum with Dmitri's original 2 board schema?

The reason my original schematic uses two PCBs and bat85 diodes along with 4051 multiplexers are these:
a. With two PCBs design if I come up with a new schematic for the Analogue board, say e.g. to expand number of inputs to 40-48, you will only need to add an additional Analogue board (or change the existing one) withoout any changes to the Digital Board.
b. I try to stick with components which are easily sourced. Sadly 74HC4851 is not a widely available component so I stick with 4051 and bat85 diodes.

Regarding the picture you mentioned. I just managed to get some 74HC4851's, that's all:)

2) Build the all in one 2.5 by Synthex viewtopic.php?f=3&t=198 . This can be done at home too, and does not use the 64 diodes and is only one board. A possible problem with this is the availability of the schema, as it is provided in gif file and not in kicad, with the risk of having size issues when printing?

3) Purchase the all in one 2.7 from Synthex, this is not intended to be done at home as it is a double layer design viewtopic.php?f=3&t=187 . This is very nice and the only downside could be the delivery time.

Are these statements correct? Please give advice otherwise.

More questions:

a) Is the PCB for 32 inputs mandatory or optional ?

What do you mean?

b) Is the firmware the same in all of these 1,2,3 build options?

The same.

c) What are the advantages and downsides of each approach besides the ones I've pointed?

1st - requires most DIY, 2nd - less DIY, 3rd - least DIY

d) What aproach 1,2,3 do you recommend?

It's up to you to deside.

e) Aproach 2 in the link provided says that the 2.7 is better than 2.5. Can you explain what is better in 2.7 and why?

On a side note: I think the information about the proyect should be arranged a little, there are pieces of information here, another there, and you only discover this information by navigating the forum by hours. This is not a troll just something that I noticed. Again, I congrat the hard working that's being done here.

I agree. Sadly arranging the information is usually last on my list of things to do. Any volunteer to do this and, say, put all the information in one document, e.g. PDF?

[japi]

The reason my original schematic uses two PCBs and bat85 diodes along with 4051 multiplexers are these:
a. With two PCBs design if I come up with a new schematic for the Analogue board, say e.g. to expand number of inputs to 40-48, you will only need to add an additional Analogue board (or change the existing one) withoout any changes to the Digital Board.
b. I try to stick with components which are easily sourced. Sadly 74HC4851 is not a widely available component so I stick with 4051 and bat85 diodes.
Regarding the picture you mentioned. I just managed to get some 74HC4851's, that's all:)

Excellent. That means that if one can get the 74HC4851 can ditch the second board? In that case the schematics to be used are Synthex's ?
Luckily we get the 74HC4851 here

a) Is the PCB for 32 inputs mandatory or optional ?
What do you mean?

Nevermind. I asked because I've seen a PCB for the inputs, but I've just saw the picture of your megadrum again and found that there's no PCB for inputs, those are directly welded.

On a side note: I think the information about the proyect should be arranged a little, there are pieces of information here, another there, and you only discover this information by navigating the forum by hours. This is not a troll just something that I noticed. Again, I congrat the hard working that's being done here.
I agree. Sadly arranging the information is usually last on my list of things to do. Any volunteer to do this and, say, put all the information in one document, e.g. PDF?

I volunteer, but my electronic skills are bad and prone to error, but let me know what can I do to help to arrange the info. Maybe this 3 options I've mentioned should be posted in the FAQ? Including links? I think that improving the FAQ a little will be suficient to help confused people like me.

Thanks.
Javier

[Beamtreetaker]

I would like to participate on a docu-project. Unfortunately my time is rare atm and I have other mega drum related tasks to finish first (controller software, ...still finishing my drums, doing a demo video I promised half a year ago... ). Maybe we should partition the documentation so that each one interested in participating can work on one specific topic like.... -building the unit, -setting up parameters, -setting up a software sampler, ... I think this way we could get to a presentable result the quickest way. The actual work would then be to comb through the forum and to extract and meld all info on a specific subject.
So, who would like to help? Someone up to collect all relevant topics and create a table of contents??

EDIT: Of course a topic like 'building the unit' should be separated into several subtopics to not make the related docu-work too huge. And..Hey, this is my 100th post, Cheers!

[jamalpiper]

I'd definitely be interested, I haven't recieved my orders yet, so I can start fresh and clean from the begining. I'm not sure what you mean, would this be more of a written thing? or video/pictures?

I'll try my best to document my build step by step when i get my shipment, which won't be till november.

[japi]

Well, based on a matter of money and personal interest, I've decided to make the board myself, with a twist:
I will be doing the digital board, and the analog part will be blend with the pcb that will hold the input jacks in place.

I'll be documenting everything in pictures, with a brief of what's being done. Starting today.

To avoid hijack this thread in which we are talking about how to document the project, i will start a new thread here

viewtopic.php?f=3&t=329

[Fulano]

Hi all,

I agree with the fact that the information in this forum isn't well organized at all. You can find anwers for almost any doubt regarding the megadrum construction. However, you must read and re-read the different threads for hours.

I think the best thing to do is to organize the forum and sub-forums, so you could have something like this:

Megadrum hardware
- Megadrum8
- Megadrum32
- Megadrum Allinone 2.7

Inside you could find different tutorials about the components, construction, pictures, etc.
For example:

- Megadrum Allinone 2.7
- Components needed
- Building: step by step
- Firmware
- etc.

There could be another subforum related to the building of the edrum and how it would work with megadrum

- DIY edrums
- Tutorial: build your toms
- Tutorial: build your snare
- Tutorial: build your cymbals
- etc.

I think it would be a good idea to establish a plan or layout for the tutorials before. For instance, a brief introduction, a step by step guide with pictures and a conclusion or final tips.

[japi]

Good idea. I'll be taking pictures of my build, so when i finish i can do a step by step, and with the help of others we will polish it up

Javier

[jamdat]

I too will be building a megadrum in the near future, once I get a few extra components. I will also document my build and post here.
I don't have any actual drums at the moment, so I'll also be building my own heads and can thus contribute to the building heads section.
My documentation will be from a complete electronics newbie standpoint .

[jamalpiper]

what about organizing all these how-to's and information into a wiki? then having links to the respective topics/sites that the information came from?