www.megadrum.info

Hi everybody this is my build report of the megadrum, just some picture to hear what you think.


this was taken as soon as i open the package


Just before start solder


finish with keyboard and screen (no backlight)


ITS ALIVE!!!!!!!


I'm still have to build the inputs board and put all in an old case of an old hub (its quite big)
more pics soon.

Credits to Dmitri and synthex and a especial thanks to japi ho without his help i would not make it.
Sorry my bad english.

Need some help here,
I build the inputs boards,put everything in the case, then i tested all inputs, and they all where working but not the "kick" input all there others worked fine, so i open the case i check everything, and put all togheter again and... the entire board where the "kick" input where its not working,
so i think that i must have kill one of the 4851, so i chenged them of place and tested again and same behavior, so 4851 must working fine,
i retested and time i touch the inputs jacks with a metal thing and its works, so i connect the piezo test and nothing, when i use the metal thing it works, excepts for the kick input,

to test the "kick" i take off the cable and put a lead in the cable where the kick should go, then i touch with the metal thing and it triggers the kick and the hi hat,

i have no idea what wrong, if some one can give a hand, i'll be very thanks

just for the records, i change the ide cable and nothings changes,
and i update the firmware, and nothings changes, but i must say thati was force to update whit ISP method cos my original firmware was erased some how.

sorry my bad english

anyone ? please..!!!

Hi,

Try connecting a piezo directly to pin 1 and pin 5 of the 32 inputs connector.

goodluck

With something metallic, like tweezers, touch pin 40 of Atmega. Do you see VU meters activity?
Again, with something metallic, touch pins 13,14,15,12,1,5,2,4 of the 4851 IC. Do you see VU meters activity?

i dmitri thanks for the help,
ok, i touch the pin 40 and i have activity at least 6 vu start to move, then i touch pins of the 4851 and found that they all work, but when i have the input pcb (synthex input pcb) there are two that don't work, and i don't know if this is normal or not.
And one more thing, there is one pin of one 4851 that works but then gets tilt, if i thouch again seem to respond but then the vu keeps up always.

I tink im gona build the PCBs again and change the cable, dont see other thing that could be wrong.

vodoochild_ar80 wrote:i dmitri thanks for the help,
ok, i touch the pin 40 and i have activity at least 6 vu start to move, then i touch pins of the 4851 and found that they all work, but when i have the input pcb (synthex input pcb) there are two that don't work, and i don't know if this is normal or not.

You have a broken connection between the input PCB and the board on these two input.

And one more thing, there is one pin of one 4851 that works but then gets tilt, if i thouch again seem to respond but then the vu keeps up always.

Top left VU meters bar? It is a pedal input and with 'AutoLevels' for the HH pedal set to 'Yes' it is normal.

I tink im gona build the PCBs again and change the cable, dont see other thing that could be wrong.

thanks a lot dmitri, i was fearing that i did a mistake on the all in one, but the synthex all in one its working fine, im gonna remake the inputs pcb and then try again, if everything works fine i will post the photos of my new all working megadrum!!!

Before remaking the inputs PCB, just test continuity for the two inputs you have problems with and maybe you just need to resolder some points or repair broken traces.

finally i found the problem!!!!, it was such a stupid mistake that i don't even think of it, until i saw it.
when i went to buy the jacks they didn't have the 17 jacks in the store, just a couple, so i buy the rest in other store.
And that was the big mistake, the jacks i get in one of the stores are backwards, they looks exactly the same but they are backwards, thats why when i touch it with something metalic it works fine but when i hit the piezo didn't.
thanks to dmitri for helping, im gonna post pics like i said when i put everything in one pice again, thanks again.