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matrigs

midibox blog: making of "the massive"

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okay so last week was a complete disaster when it comes to midiboxing.

my goal was to finish the box without the encoders and ledrings, but with the buttons and all analog inputs until friday when i was meant to be playing before deadbeat. on tuesday i got the last batch of parts and started soldering - soldering 3 days trough not sleeping, eating, not going to school stressed about finishing on time.

at thursday i wanted to add the last part - the second ain module. of course when i connected all the potentiometers and switched it on - hell broke loose. massive random events. i thought - nothing new probably due bad grounding.

so i sat down at 19.00 at thursday and at 10.00 friday morning (no i haven't slept all night just soldered) i came to the conclusion that something is terribly wrong - i made a few dozen bridges to grounding points in various congigurations - still nothing. the ain module is perfectly soldered so i have no clue what was happening.

but things even got worse - on wednesday i was able to fire up a half-baked version consisting of 3 rows of pots, 8 sliders and all the buttons (one ain, one din, one dout) which was the minimum i would need for the live set. now even when i completely disconnected the second ain that caused me the above problems i still had random midi data. but the ain inputs where completely grounded ! i came to the conclusion that it must be because my power source is too low!

so i changed to a 12 V 1500 mA power source (really a huge thing) and still nothing - i had to disconnect the bridges with grounds of a few pots and suddenly - it worked! so i guess it's still powering.

but there were more problems - now when i was switching on more than exactly 11 leds - shutdown and reset!

i had to call my friend so he could bring me his behringer bcr2000 so i could at least partially play my set - but when deadbeat was rocking and playing some awfully good music i was of course setting behind him linking all the pots to my setup... and this after 3 days of non-stop soldering.

so could anybody help me with this? i mean - is it the power source? but i mean i think it's not good to connect a voltage higher than 12 volt to the core? so what might be the problem ??

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12V is almost too much for your 7805. 9V are enough. but You can take a look at the current of your psu. Perhaps its too small.

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my setup didn't want to fire up at 9 volt after i connected the 40x2 lcd.

and i really don't want to add another core to this...

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What's the amperage on the 9V PSU? Don't read the box, get your meter out :)

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Nice work playing with deadbeat, i saw him play about 5 times when he came to melbourne a few months ago, he's awesome. Nice guy too.

I'm in a similar situation, I have a gig this thursday playing with swayzak, who were a really big influence on me when i was starting to produce. I've been trying to finish my midibox before that gig, but there's no hope now, luckily i have other midi gear i can use.

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Deadbeat, Swayzak... you people are playing with some serious people. That is great!

Matrings, you are definetly having PSU with not enough power. I had the same problems like you. As stryd said... get your meter out and check how the specs are wrong.  ;) Mine was also declared 1500mA

I am really sorry you didn`t make it to finish your box before gig. There is too much stress involved if you have deadline so you can make some errors. Also when you don`t sleep enough, even more errors happens. 

@ Patstormont

When you say

AUD$.95 each, or about US$.70
I tought you are speaking about some other source as this hungarian shop have prices in EUR. 

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just a comment - and please don't take this the wrong way (esp if you STILL haven't slept).

But I think you are mad:

a) trying to solder with that little sleep,

You make mistakes, you get clumsy and it's no fun. I won't even go near drilling holes or cleaning up acid baths if I'm at the end of a day and tired.

b) using a midibox live that is not properly battle tested

The potential for disaster is way way too high. I won't even trust stuff I bought from a shop if I'm giging. I bought a new audio/midi interface to gig with, but even though I tested if for weeks in the studio b4 gigging, I still took my  old one just in case when I did my recent South African tour - another lesson learnt (for once the easy way), because as it turned out I would have been screwed as the new interface was giving a way low out (fine in the studio, not so fine in a club with no sound tech around and all the other DJs are at 100% of everything on the mixer) - a 4db drop ain't doing you no favours on the dancefloor...

I've played in clubs b4 where the power has cut repeatedly: darkness, then emegency lights, and then lights and sound back on after a couple of mins.

THE WHOLE TIME this is happening - boos and cheers from the crowd, getting worse with each time.

My fault? Nope!

Do the crowd know/care? Nope!

Is it any fun? Not much, no...

Imagine how you are gonna feel if your set goes horribly wrong cause of something you are 100% resposible for. And of couse let's not forget the reaction of your fellow DJs - it's not exactly an unbitchy scene and the ammo you'd give any jealous/small minded ppl would be massive...

Anyway, good luck with the box, I'll be following your progress with interest.

Test, test, test and then blow the b'stards away in confidence you are armed with battle tested kit....

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i'm a bit lost now guys...

ok - i checked the voltage of the psu and it gives now unconnected a steady 17 volts!! which is quite weird because i checked before the gig and it was giving 14 volts?? weird stuff...

the current is meant to be 1300 mA... is that enough? i have never checked before so i don't really know how to do that....

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ok - i checked the voltage of the psu and it gives now unconnected a steady 17 volts!! which is quite weird because i checked before the gig and it was giving 14 volts??

14V > OK :(

the current is meant to be 1300 mA... is that enough? i have never checked before so i don't really know how to do that....

That should be enough normally, but maybe not, with all those LED's. Maybe someone better with hardware could advise you, but they'll need to know the specs of the LEDs and LCD

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it's getting even more weird!

i just launched the whole thing with my multimeter on amper mode.

now when i launched the box it shows me a steady 0,23 on the screen which i assume must be 230 mA.

now when i start to launch the buttons it starts to grow and grow until it reaches 0,41 and then the box resetrs itself.

but 0,41 would mean 400 mA then and the PSU is meant to be 1300 mA. and it's a proffessional PSU for a WALDORF syntesizer so i doubt that this is some hoax...

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9V 9V 9V ===>> the more you take ... the faster your 7805 is f*ck*d up.

Your amperage has to be measured in a series connection. so dont measure it parallel at your psu.

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i measured it serious ! otherwise the amper meter wouldn't show me anything anyways (as far as i know from physics....)

but as i said - putting 9 volts on my psu makes it a no-go. nada.

could anyone recommend me something? higher amperage ?

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need to know the specs of the LEDs and LCD

Spill it :)

9V is a maximum you should need and can safely use. If it won't power up, more amps, but never more volts.

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you read that word 'never' ;) ?

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so what do i have to suddenly use two amps switched in parallel or what ? what madness is this ?

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Just go to the store and get a 9VAC 2A Plug pack.

Of course, that much current might blow the thing to bits for all we know, because we still

need to know the specs of the LEDs and LCD

That's three times now :P ;D

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Hey wasn't your plugpack 14VAC@1.3A?

How many amps is the 9V?

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http://tme.pl/microswitch-pcb-mounting-monostable-led-white/arts/en/a25/pb6141l-1__2.html

info about the buttons above.

i have two power sources - one was my old psu with regulable voltage from 3-12 volts with a maximum amount of 500mA. i used it on 9 volts on my old setup. after the lcd drained it to zero i switched it to 12 volts and it worked fine.

now when i have also those buttons i connected the 12 volt 1300mA waldorf PSU which still seems not enought...

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Yeh it might well be overloading things.

9V 500ma is no way going to be enough. Maybe someone can tell you how much exactly you'll need given those LED's.

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i found a psu at a local shop with those parameters: 9V, stabilized, 2000mA - would that be enough? it's horribly expensive so i hope someone will be able to justify this before i throw out money and end up still not being able to fire it up.

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also - in the midibox lc topic above there is a 15v/3A psu mentioned which works fine so what about that sticking to 9 volts ??!!

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i found a psu at a local shop with those parameters: 9V, stabilized, 2000mA - would that be enough? it's horribly expensive so i hope someone will be able to justify this before i throw out money and end up still not being able to fire it up.

you can easy DIY it. You only need a few parts. Probubly cost will be 10-15euro.

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I`m not a prof but I always use this from TK`s digrams:

- Adjustable Power Supply    (for egzample MF module)

- Fixed Power Supply (like in core module).

If you need 9V please change value by pot in first case or simply use 7809 in second.

If you need more current please use more voltage regulators in parallel.

I hope it will help.

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