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Put Waveblaster daughter board (Yamaha DB50XG) in a box?


SeverityOne
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Hi,

The other day, whilst going through old PC hardware, I found my old ISA SoundBlaster 16, with the Yamaha DB50XG daughter board stuck to it.

Now the SoundBlaster 16 is useless in this day and age - you can't even rip an FM chip off it - but the DB50XG is an interesting little sound generator. Which made me wonder, how difficult would it be to make a small box with a small PCB and some MIDIbox components?

There are several resources on the internet about either the Waveblaster or the DB50XG (like this one, this one and this schematic), but these deal with building a board that converts the TTL signals of the board to MIDI, via an opto-coupler and buffers for the MIDI Thru (the interface does not have a MIDI Out; at least, the DB50XG doesn't).

Since the MIDIbox hardware also works on TTL level (right?), what would be needed, apart from a Core module and something like an AIN (for knobs), DIN (for buttons and data wheels) and/or DOUT (for LEDs) modules?

The MIDIbox boards would need to be able to handle MIDI In and Out (for proper MIDI ports), and an extra MIDI Out (on TTL level) to control the daughter board.

Software... that's another issue, but it should be feasible enough.

Any help would be greatly appreciated.

- Peter

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I had a 1U DB50XG some years ago..  I didn't convert any TTL signals (afaik), If I remember correctly, I just created a plexiglass case and powered it up.  I had a reset switch, audio,midi and power connection.

Used it a couple of years.

Maby I was lucky.... have you tried (without TTL conversion)?

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Thnaks for the replies so far.

Well, finding the DB50XG is not the problem; I bought it at a musical instruments shop way back, which has since long gone. The problem is that I'm not very familiar with the electrical properties of electronics: logically I understand everything; it's when it gets to complex figures, capacitors and resistors that my mind draws a blank.

And, of course, I wouldn't want to risk damaging the DB50XG. But it seems such an excellent project to convert it into a MIDIbox XG or something like that.

- Peter

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I will go easy, because I had to refine the search three times to get useful results... But use the search engine :P

Midibox Link question

R6 vs Gameport to J11

internal connection to msid or mbseq possible?

And the really good one....

Final design questions

I think I will use searching for those posts as my wiki search-engine-how-to document. They're there, but it took some trickery to find them. Hope they help :)

Where are you nomical? :)

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The question is, what can be edited through midi.

I don't think a lot. It's a ROMpler, right?

Get a midi spec for the thing and then build an MB64 around that.

Well, my EX5S is a rompler too, among other things, but you can control quite a few parameters. It's been a long time since I last looked at the manual of the DB50XG (which comes with the complete MIDI specification) but you can control quite a few parameters, from what I remember. It's not unlike the CS1x keyboard, and identical to the MU-10 module in regards to sound capabilities.

mu10m.jpg

Admittedly, that's not a lot of controls. :)

So on the one hand it's a simple General MIDI device, but this being Yamaha, you have three effects processors as well, plus set of resonant filters. More info can be found at Sonic State. (Karaoke chip? Oh dear.)

This is the reason that I had this idea, because it's such a lovely little board.

- Peter

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So... I had a look. My question about the two MIDI Outs may not have been entirely clear. What I meant is that there should be the usual MIDI In and Out, to communicate with the box. The In, well, that should be pretty clear, and the Out would do things like patch dumps.

However, apart from reacting to the messages coming from the MIDI In, the DB50XG would have to react to the signals coming from the Core module (turning knobs, pushing buttons, etc.), and these would be different from those going to the MIDI Out.

Unless it's too much of a hassle, and not worth it, in which case the MIDI Out could be sacrificed.

But I think the second MIDI Out, at TTL level, might be connected to J11. However, this is the point where my understanding of the MIDIbox platform hopelessly falls short. Any hints in this regard would help me a great deal, because it looks like a Core (which I have one spare), a DIN and a DOUT (both of which still have to built into a SEQ box), an AIN (for the knobs or sliders) plus a small custom PCB would do the trick.

Thanks again,

- Peter

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regarding db50xg, i know that somewhere, on internet, there are schematics to make a PCB to connect the db50xg via midi to a PC (for exampel), making it a standalone synth.

i had downloaded the files once, and i have to find it if you are interested.

moreover, there is a shareware editor for the db50xg (somewhere in the net...) which permit to use the daughterboard to its extreme (as for example making using 4 oscillator all together to make 1 voice).

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db50xg can emulate QS300 sounds.

Check this site - http://www.midiweb.de/ - there is a program called 'XG-Gold' - IMHO best editor for db50xg.

As You can see on the screens, there is a lot of things, which can be controlled real-time (4 parts, each with independent LP filter with envelope etc...).

In fact i was thinking about building dedicated midibox surface for db50xg in QS300 mode, but I didn’t realized this plan so far...

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Looking at the schematic of the core module, the MO pin of J11 is physically connected to the output at J12. So sending different signals to those two ports is not going to happen. Obviously, I could connect the MI pin to the MIDI in of the DB50XG, but then I wouldn't be able to send messages from knob movements and button presses to it.

So, back to the drawing board.

- Peter

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Elektor Magazine had an article about converting DB50XG to a standard midi sound module in issue 7-8 / 1997.. Their add-on board added PSU, output amplifier and midi connectors to card. I know I have this magazine somewhere, but no idea where exactly :/.. I guess you could also buy a pdf version from their website.

Makes me wonder where the hell did I stash that DB50XG card I had, it would make a nice Midibox project.. ;)

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Whilst going through the documentation, it became clear to me that there's just one MIDI path throughout a core module. So yes, I'd need a separate MIDI Out (and In, for those Waveblaster boards that support it).

My plan is to design a PCB with more or less the components of the MIDI I2C module, minus the opto-coupler, plus the components needed for the PCB that el-bee mentioned, again minus the opto-coupler.

The problem I have at the moment, though, is that I can't for the life of me figure out how to add a shape to a schematic design with Eagle Light. But give me time. :)

Another idea that came to me is an adapter for Yamaha PLG boards... but let's start with this one first.

I'll have a look at that Elektor magazine.

Thanks again everyone,

- Peter

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