TR909 voiceboard and MB808 Midibox Seqencer

[Acid303]

Hi,

i have a fully working original TR909 voiceboard. No power unit , no switchboard, everything else is here and working (tried it with a 2nd 909).

Now i'd like to use that board as a midi expander.

I have no clue how to connect a Midibox Seqencer or Core Module to that voiceboard. I know that there are two sockets on the voiceboard called CN1 and CN2 which are responsible for midi and triggering. There are D1-D6, 5V, ground on CN1 and on CN2 the connections are: 11 and 12 are the triggers....13-20 is Accent for each instrument.

Here are the schematics:

http://manuals.fdiskc.com/tree/Roland/Roland%20TR-909%20Service%20Manual.pdf

Is there a way to connect it?

I also found this:

http://www.msc175.de/geraete/DL-909/DL-909_midi_interface.htm

That is a midi board for a 909 clone. I figured out the D0-D5 connections but have no clue how to connect the rest.

Maybe there is someone willing to help?

Thanks in advance...

Regards,

Axel

[ssp]

i have no idea axel but .. if you ever come across a board again :o :o :o.. let me know! ;)

[creatorlars]

Triggers are very easy -- you will connect the DOUT triggers directly to the trigger inputs for each voice.  They should trigger just fine.  Accent is a bit more difficult, I don't think you'll be able to give each voice it's own accent channel in the default MB808 configuration.

The easy way (no accent at all) is just to connect the accent & trigger inputs of each voice together.  Then each voice is fired with a preset velocity.

A roundabout way is to build a custom Midi-to-Trigger application so that your voice board just has a midi input.  Or use an existing midi-to-trigger project or midi retrofit kit out there, etc.  Then build your MB808/SEQ as a separate unit. 

I can help answer more questions if you have any -- I am building a full 808 clone and I used a modified version of the Midibox CV code to build a Midi-to-Trigger interface for it.

[u-link]

Hi,I've been lurking around here for quite a while. I actually have a spare 909 voice board, too (which I haven't tested yet, but it is new, purchased some years back when Roland still had them on stock by a friend), and had the same idea.

I was thinking that on the v4 seq, with its sixteen drumtracks (or the dedicated MB808 seq), it might maybe be possible to use two tracks for the 909 sounds that support accent, one for the unaccented, one for the accented (quite like this is handled on the real 909), implementing it so that when the MIDI-interface on the 909 receives the second note, it also triggers the accent circuit on the 909 board.

[Acid303]

1st: Thanks for your answer.

Yes, i guess the V4 Seq or dedicated MB808 seq is the best solution. Actually I got a Dout board and several core modules left from my former Midibox Sid project. I have a MB6581 so i can reuse all Midibox Sid parts.

I am not quite sure which pin from the dout board i can use to trigger a sound. I guess I have to study all MB808 topics to find out about that.  I am also not sure which pin of the voiceboard of CN1 and CN2 i have to connect to one pin of the dout board. I guess that will be try and error for me.

What is necessary to trigger e.g. the bassdrum? 5V impulse? What are D1-D6 for?

Regards,

Axel

@u-link: you do not also own a spare switch board?

[creatorlars]

Yes, just study the various documentation/schematics/wiring diagrams for the MB808 and MBSEQ stuff.  You shouldn't have to trial and error it -- just look at the 909 schematics and find the trigger input point, then find the corresponding junction on your voice PCB.

Any pin from the DOUT can be used to send a 1ms 5V pulse to trigger the sound.  However, an accent signal has to be present as well as the trigger signal, in order for the sound to fire.  So for testing, tie the accent & trigger ins together.

Can you upload a picture showing what you mean by D1-D6?

[Acid303]

http://manuals.fdiskc.com/tree/Roland/Roland%20TR-909%20Service%20Manual.pdf

This pdf are the service notes of the 909

Go to page 11. Then on the left side you see CN1 and CN2. On my working 909 i tried to find the 5V on those pins when a sound is being fired up. But all pins are showing about 4.59V. And they are not changing no matter what i tried.

Then I remembered that the 909 has a trigger out. You can use the rim shot sound.

So I used this signal (and that is a 5V signal) to find the trigger points. And finally i found them. So now i am able to send a 5V impule to trigger each sound. Not bad :)

But unfortunately i was not able to fire up a sound by using the CN1 or CN2 pins. I used directly the pins of IC1 and IC10. IC2 to IC9 are responsible for Accent in conjunction with a resistor network which is responsible for the volume.

Maybe i really have to tie accent and trigger together at first. Have to try that in the end.

Any idea how CN1 and CN2 are working?

Just tried to find how the MB808 is sequenced. I guess that it is a bit similar to the 909?

How did they solve the accent and trigger thing?

Can you send me the link to the wiring between MB808 and Seq V3? Just to see how the MB808 is triggered by the Midibox Seq V3?

Ah, ok just found some information. I guess i just have to use another 5V output from the dout board and put it directly to an accent input of the 909.

The more i am studying all information the more i get the feeling that i really can make a MB909 out of the destroyed TR909 ;)

Searching for the Dout and Din board wiring. Which pin is for what? Is it the same as with the Midibox Seq V3?

Cu,

Axel

[TheAncientOne]

It looks as if 6 bit data is presented on CN2, and CN1 selects which, (4174), latch the data is sent to. 8 latches implement simple 6 bit digital to analogue converters, and the other 2 seem to be triggers Some of the latches provide accent volume data, eg IC3 is the bass drum accent level.

It would seem that the cycle would be to set the latch contents for the accent levels on the drums you want to use, then issue the triggers through the other latches.

I haven't time to take a deeper look at this, but yes: a MIDIbox to 909 seems easily possible.

You could use a manual pair of switchboards to test them out. You'll need 6 plus a reset on CN2, then 10 on CN1. Switches should have something like 4K7 pull up to 5 Volts and switch to ground, (switch 'ON' = a zero input). The data may be inverted. Since the resistor networks usually consist of 6 identical values, (unless they are a 'special'), then there may only be 6 levels of accent.

IC1 and IC10 are the trigger latches.

Hope this helps.

[u-link]

@u-link: you do not also own a spare switch board?

no, I don't, the only thing I have is the voice board. Except for my intact 909, which I have no intention of slaughtering - it might get sold if this ever gets to work, though.

The 909 service manuial also states that the trigger signal on the 909 is 2 ms in length, can that be changed?

Thinking more about it, using two separate drum-channels on the Seq might not be the best idea, as you don't see which steps are on at one glance - thought about that as I mainly use the 909 in Tap mode, not Step programming.

I think it would be easiest to just connect the trigger of the Dout directly to the input of the sounds, after the IC1/10, right?

The easy way (no accent at all) is just to connect the accent & trigger inputs of each voice together.  Then each voice is fired with a preset velocity.

So if you only send a trigger signal to the trigger input, without triggering the accent, there is no signal output?

Regards,

Gabriel

[Acid303]

http://www.engineersatwork.nl/catalog/product_info.php/products_id/536?osCsid=f54b5fa7e7bdcd41ca41590bfefda01f

This interface might be the right thing.

- Has 23 trigger outputs ( 5 volt positive puls, selectable 1ms or 10ms per pulse )

and yes, i tried it on my working 909. You can trigger a sound directly at the trigger points of IC1 and IC10. E.g. the bassdrum can be triggered if you send an impulse to the specific pin of IC1. If you like i can give you the exact position. But i don't know about the accent thing yet. If it triggers without accent or not. With the rim shot trigger signal it worked.

As I got a midibox core , dout and din board left, i will try it with the MB808 version and see how it works.

[u-link]

http://www.engineersatwork.nl/catalog/product_info.php/products_id/536?osCsid=f54b5fa7e7bdcd41ca41590bfefda01f

This interface might be the right thing.

- Has 23 trigger outputs ( 5 volt positive puls, selectable 1ms or 10ms per pulse )

and yes, i tried it on my working 909. You can trigger a sound directly at the trigger points of IC1 and IC10. E.g. the bassdrum can be triggered if you send an impulse to the specific pin of IC1. If you like i can give you the exact position. But i don't know about the accent thing yet. If it triggers without accent or not. With the rim shot trigger signal it worked.

That might be the easiest idea. I also thought about using a "Wiring" board, which I guess you could program to do the triggering (well, not me, but a friend of mine who knows programming).  At least for making an expander. The much cooler thing would obviously be a complete MB-909 thingie with integrated sequencer...

But you are applying the rim trigger to a point AFTER IC1/10, right? Please post anything new you find out here, that would be much appreciated!

[TheAncientOne]

Like I said - you need a board with 1 data port, (8 bit, but only 6 used), and 10 I/O selsct lines, which could be decoded off another 4 lines. 8 data writes to set up the accent latches, then  write the required lines in latches 1 and 10 high then low to trigger the sounds.

As I said, all you need to test them are some switches resistors and wire.

Sadly a standard Arduino has only 13 digital I/O lines available, so you would need (say) 2 74HC138's cascaded to decode 4 lines to the 10 needed, (actually 16, so you could use the other lines to address peripherals). A MIDIbox core would be better, because the MB808 code would be a good start, and it has more spare lines, as well as an LCD interface. Downside is the programming is harder.

I have used a tecnique like this to address some other drum voice card, years ago, driving it off the 1MHz bus of a BBC micro, and later converting it to run from the parallel port of a PC. I can't find the data on the last one, it seems to have got lost, though we could get quite good beat patterns from a program written in QuickBASIC on a 486, (which tell you how long ago thta was!).

Hope this helps - it would be a well cool project to get running, and since, from a repair point of view, the sequencer and buttons in a 909 are more of a fail point than the voice card, you might have a way to revitalise one or two dead 909's.

[Acid303]

Hi,

thanks again for you advice :)

I think the midibox solution is the best way because it is the closest you can get to a real 909 with the sequencer. I know Thorsten Kloses software and it is very very good. I also own the MB6582 and i am really confident with it. Thanks Thorsten!

As far as i know  the MB808 solution has two velocity states? With accent or without accent? But thats nearly the same thing with the real 909 sequencer.

What i dont know so far is how the MB808 reacts to Midi? Velocity sensitive? Or also accent or without accent?

The best midi solution would be the midi to trigger interface:

http://www.msc175.de/geraete/DL-909/DL-909_midi_interface.htm

Be careful : it is german ! As i am :)

But this is the closest to the original as possible i guess. Look at the schematics.

But how do have to connect them? Which pin to which pin? D0-D5 from midiboard to D1-D6 on the voiceboard (909)? And the rest?

Maybe someone can help me with that finally ;)

@creatorlars:

hmmm...you said that every pin of the dout board sends 1ms 5V? But i guess that if you like to trigger e.g. the BD of the MB808 there is a specific pin for that? Didn't find the exact pin assignment for the MB808 on the Dout board. Only the assignment of the MB Seq V3. But how each sound of the MB808 is triggered? Don' t know.

Cheers,

Axel

[Acid303]

Update:

@theprof: i think i know what u mean, but i guess that is a bit too complicated for me. What i tried is: i used my old MB core and 1 dout board. I used one pin with 5V.

Triggering didn't work if only the trigger pin is used. no sound.

Tried to find a way to trigger the BD but i have no idea how. so i looked for the accent trigger but i don't know where. I know that it should be Pin 14 of CN2 but how do i activate that? Also 5V didn't work . But maybe because i tried it with my working 909. And there a voltage is already there. So i guess i have to seperate it from the switch board first?

I keep on searching :)

[TheAncientOne]

Tried to find a way to trigger the BD but i have no idea how. so i looked for the accent trigger but i don't know where. I know that it should be Pin 14 of CN2 but how do i activate that? Also 5V didn't work . But maybe because i tried it with my working 909. And there a voltage is already there. So i guess i have to seperate it from the switch board first?

I'd try a 4K7 resistor, connect one end to +5V and touch the other end to the base of Q1, (the junction of R1, R2 and the base of Q1). I think you should get some sound, even with nothing applied to the accent input.

[Acid303]

ok, that worked ! Got a sound without accent. The BD is a bit too soft that way :)

So what is the next step? how do i connect it to the dout board finally? do i always need the 4k7 resistor? or how does this work? For the MB808 sequencer i need a BD with and without accent.

Thanks theProf...

add: ok, i need a voltage from 5 to 15V to get a harder/louder BD. The MB808 solves this with the accent circuit. oh oh...how do i do that...

In my opinion i should go for the midi to trigger interface:

http://www.msc175.de/geraete/DL-909/DL-909_midi_interface.htm

after this works i would like to add the standalone MB808 sequencer which is discussed in this forum. So i have two seperate devices which i can use individually or together...

[TheAncientOne]

When experimenting, always use the resistor, it is too easy to fry a transistor or IC output stage with a direct 5 Volt connection.

It would be possible to drive the system with DOUTs, but there might be timing issues with the latches.

Over the weekend I'll have a look at it - driving the board through the normal interface may not be that hard

To get the proper range of accents, you will need to master art of driving the latches.

Best wishes

[Acid303]

That would be great ...thanx

http://www.msc175.de/geraete/DL-909/PDF/DL-909_DRUMSYNTHESIZER_MIDI_FULL_DOCUMENTATION_MSC175_DE.pdf

This is the complete documentation of the midiboard. It is in german so if you have any questions i will translate it for you...

Axel

[Doug Wellington]

Would you be interested in a standalone version of the MB-808 sequencer?

[TheAncientOne]

Cool idea Doug - I can imagine that hooked up to a couple of rows of analogue drum modules.

Perhaps some kind of VCAs could be 'wrapped' around the modules for a general purpose accent system.

A nice modular, flexible idea.

[reboot]

doug's MB-808 sequencer is the best choice ...with a A/B button too (maybe thre's a way to do it by the menu)

[jojjelito]

Now this is the life. Imagine marrying the sequencer board and the 9090 voice boards in a nice-looking table-top case. Say hi to your own, fully serviceable MB9090. Now bring me some beer to go with this tasty Gumbo  :P

[Doug Wellington]

Exactly!  Mock up picture at the bottom of http://www.midiboxaddict.com.

Details will be at http://www.nine-oh-nine.org (to match http://www.eight-oh-eight.org of course!)...

[SubContractor]

Ah yes! This is the one with 32 step buttons right? (or was that 64?;)) Can't wait for it, am finishing off my 9090 now, having just finished off my MB6582.... Oh yeah, put me down for one of those cases too!

Regards

Andrew

[Acid303]

Well this is an old post which i started because I fried my TR909 CPU :)

Just to tell you how this ended...

A guy from Scotland repaired my 909. He not just constructed a complete new PSU which fits exactly in an original 909 case he also repaired all damaged parts and changed a chip so that the 909 has 4 times of memory and don't needs batteries anymore. The 909 now has a switch on the back and i can switch between the banks even if the sequencer is running. I am very very grateful..he did a marvelous job.

Thanks for all posts :)

Edited June 19, 2011 by Acid303