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MB808 drum seq standalone


creatorlars

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BTW I like the case design too... esp. the nut in the PCB, I'd like to see how that turns out (and then steal the idea) :thumbsup: I've thought about whether it's possible to solder a metal threaded spacer horizontally to a large pad on the PCB (i.e. ground plane without solder mask)... maybe it's also possible to hold a nut in place with a few solder joints.

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Nice work, Sasha... I like the changes :thumbsup:

Thanks mate.

If you want to use the "C64" rocker switch (like MB-6582, sammich*, kaffeSEQ), I just ordered 500 and have plenty to spare for any PCB/kit bulk order.

That is great. I really like that switch. One part sourcing problem is solved. Do you have some extra x0xb0x/MBseq style buttons left? :P :D

By dropping the gap to 10mm, you now need to worry about clearance for the power socket and switch...

Hmmm, i totally forgot about those. Thought MIDI sockets and 2200uF capacitor are only thing to worry about. And, I thought this is final revision...

BTW kaffeSEQ is mostly nILS' design, please direct all design criticisms to him :poke: I just do all the boring stuff... :wacko:

I didn`t see all the kaffeSEQ details, but I really like how it is done. Great work Nils!

BTW I like the case design too... esp. the nut in the PCB, I'd like to see how that turns out (and then steal the idea) :thumbsup:

Sure, we are all here to steal each other knowledge and experiences. ;)

I've thought about whether it's possible to solder a metal threaded spacer horizontally to a large pad on the PCB (i.e. ground plane without solder mask)... maybe it's also possible to hold a nut in place with a few solder joints.

My initial idea was to use metal epoxy to glue 5mm female metal spacer to the long vertical spacer that holds 2 PCBs, but I think this is better solution.

Meanwhile, I changed this idea, again...

Even I really like laser cutting sometimes it is needed to employ other machines or even hands in the worst case.

So, instead of using vertical acrylic plates and glued nuts, it is really better to use 3mm aluminum plate and make an M4 thread in it, even I need to make a thread by hand.

Edited by Sasha
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Well, long time has passed since that, we`ll see. I would probably need some help regarding organizing batch of buttons and caps from Digikey or Mouser.

I could do the mouser / digikey stuff but swedish taxes would make them more expensive than necessary...

Edited by strophlex
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Only just noticed this topic. I bought pcb for 9090 project about a week ago. With the MB808 in the back of my mind i already thought about looking into a nice sequence solution for it as well. Very cool indeed. Guess i don't have to design something myself :thumbsup:

I will be following this with great interest. I would be interested in a bulk order if there is going to be one.

Edited by Shuriken
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Just to let you know I trashed my PCB design. :(

When I finished everything and just before I sent files for PCB prototyping, i read the thread about possible problems if SC/RC lines are mixed between DIN and DOUT registers, which is exactly the case with my design. Maybe there will be no problem as all the register ICs are pretty close to each other, but I can afford only one prototype set.

The PCB is pretty dense so there is no way I could re-route the lines properly. If somebody is willing to help me with matrix I could make new design, but there is no way I route again PCB from scratch with all 14 registers. Sorry guys.

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Just to let you know I trashed my PCB design. :(

When I finished everything and just before I sent files for PCB prototyping, i read the thread about possible problems if SC/RC lines are mixed between DIN and DOUT registers, which is exactly the case with my design. Maybe there will be no problem as all the register ICs are pretty close to each other, but I can afford only one prototype set.

The PCB is pretty dense so there is no way I could re-route the lines properly. If somebody is willing to help me with matrix I could make new design, but there is no way I route again PCB from scratch with all 14 registers. Sorry guys.

How can we help, do you have the pcb design online? and what program did you use?

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How can we help, do you have the pcb design online? and what program did you use?

Well, you can help if you know how to configure MB808 firmware to work with BLM, it will free a lot of room on PCB, so I can make new layout and route SC/RC lines properly. I was checking the code of SID, and SEQ app. but to me it looks they are configured completely differently and I cant figure out those virtual registers. On SEQ virtual registers are counted from 17 to 24, but where in the matrix should be connected button 17? I didn`t find any schematic with labels where is physically each virtual register located on the matrix net.

In the MBSID, register configuration is done with "16+" which is even more confusing to me if I try to compare it with MBSEQ.

Only thing understand from the code is how to enable firmware to use it BLM, but not how to use it. Maybe I`m bit rusted from the years of inactivity or maybe it is just too complicate for non-programmer like myself to figure it out.

what exactly is the problem then?...can´t find anything regarding this issues...can you provide a link?

cheers, nik

Look at the attached picture of my PCB design showing SC line highlighted. This is not how register ICs should be routed. SC/RC lines should go from first SR to last one, and separate for DIN and DOUT, but I find out too late about it.

post-3921-087991000 1291965696_thumb.gif

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Sure, 1.27 is not hard to solder, but still it would make it undesirable to people with less soldering experience. Another reason is doing all the work again. It took me a lot of energy and time until I was completely satisfied. 14 register ICs are too much if it can be done with only 4 or 6.

Edited by Sasha
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Look at the attached picture of my PCB design showing SC line highlighted. This is not how register ICs should be routed. SC/RC lines should go from first SR to last one, and separate for DIN and DOUT, but I find out too late about it.

...but why could this be a problem...? would be interesting , cause i did a layout myself sometime ago, not really finished, but my prototype worked so long...i didn´t do the "straight"-line stuff either...so is there a link what will explain the issue, what happens when not connecting the "right" way?

cheer, nik

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...but why could this be a problem...? would be interesting , cause i did a layout myself sometime ago, not really finished, but my prototype worked so long...i didn´t do the "straight"-line stuff either...so is there a link what will explain the issue, what happens when not connecting the "right" way?

cheer, nik

we get a more difficult situation once a DIN chain is clocked by the SCLK signal in parallel to the DOUT chain: parallel chains can result into two "ringings" (one from the DOUT, one from the DIN chain - if they have different lengths resp. impedances.

The situation will become even more difficult if DIN/DOUT registers are connected to SCLK in mixed order, in this case it can happen that the serial data won't be shifted correctly anymore due to setup/hold time violations caused by unbalanced clocks (with different delays) at SR inputs.

This results into the effect that bits could be missed or added in the DIN and/or DOUT chain at random moments and positions (-> flickering LEDs, random button events) - this effect could vanish if you put your finger on the SCLK line (see also next point)

I have experienced flickering LEDs in past with other project and it didn`t stop when I add terminators at the end of the chain. A friend of mine had similar problems too, so I get DIN DOUT registers can be problematic sometimes and especially if they are not routed properly.

Edited by Sasha
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Another reason is doing all the work again. It took me a lot of energy and time until I was completely satisfied. 14 register ICs are too much if it can be done with only 4 or 6.

Well, I did not mean that YOU should do this, but anyone interested enough in this could. For smd, there is actually plenty of space available.

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Good news. TK checked my PCB and said situation is "relaxed" so I`m continuing with 1st design. :)

There were some changes on the design meanwhile. I left out LED BPM display from the CS PCB, but kept pin connector if somebody still like to add it in integrated designs like TR-9090. There is a DOG LCD on it`s place now. Even I wanted to make it clean and simple it will be really hard to navigate trough all the functions without proper panel labels. Main reason I decided to use DOG LCD, is because of its very small size and low profile. It fits nicely with minor controls rearrangement without cutting the PCB. Even it is not so easily awailable, especially from where I live, i feel that DOG is a way to go for this design. Distance between PCBs are grown back to 20mm, and that is about all for now. I`ll let you know the news.

Here is the splash of the arrangement.

post-3921-066725600 1292595322_thumb.gif

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Good news. TK checked my PCB and said situation is "relaxed" so I`m continuing with 1st design. :)

There were some changes on the design meanwhile. I left out LED BPM display from the CS PCB, but kept pin connector if somebody still like to add it in integrated designs like TR-9090. There is a DOG LCD on it`s place now. Even I wanted to make it clean and simple it will be really hard to navigate trough all the functions without proper panel labels. Main reason I decided to use DOG LCD, is because of its very small size and low profile. It fits nicely with minor controls rearrangement without cutting the PCB. Even it is not so easily awailable, especially from where I live, i feel that DOG is a way to go for this design. Distance between PCBs are grown back to 20mm, and that is about all for now. I`ll let you know the news.

Here is the splash of the arrangement.

That's good news. TK to the rescue once more.:thumbsup:

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  • 3 months later...

PCBs are ready for prototyping for quite some time, but I put my money savings and efforts onto 303 style sequencer(stripped x0xb0x)as it seams to have more perspective.

Not sure is there enough people interested into drum sequencer to pay itself. But some small prototype series could be done.

Edited by Sasha
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