e-licktronic Forum

today i listened to a track i made after doing the BD fix, with a M5218AL, there is no buzz, nothing ! at the moment i have installed a M5218L from ebay, with this i have some "buzz" but not like before non stop, just on every step... there are no cables near the BD section, except for the fix cable of course...
so gonna try the other M5218L, if theres a buzz too, i'll go back to the AL ...

Hi, is it ok, like this?:



Obviously i cut trace. i just tested by triggering and i really really not convinced by the result.
I usually when i built a DIY, controlling each module one by one, as and as i advance in building.
Power supply and noise are perfect, but BD not good...
I compared by triggering a hexinverter BD909 module and the result with hexhinverter more convinced. I could compare against a MB909 or TR909, but not worth the hexinverter enough ... With nava BD i have no punch and the sound is not clear ... I made a mistake or not by making the correction? See attached picture. Thanks

decoder303 wrote:about the lvl problem, I couldn't replicate the behaviour why some steps have a higher level sometimes. I only know that, if 1 step in a pattern has higher volume it will stay this way until the whole eeprom gets initialized. Might be a (not perfect but working) work around for people who also have this issue. Seems that somehow some information is "stuck" in the memory and stays there until the init procedure is done?.

Can you explain this initialize procedure a little more decoder?

Dr.Knob wrote:Hi, is it ok, like this?:

Where did you cut the traces? You need to cut them at two places (IC11 pin2 and VR4 pin1)!

Obviously i cut the traces, on a white PCB that is not seen. (I have since checked with my multimeter, pin 2 of IC 12 is no longer in contact with Q12 / Q6 and VR4 pin1) I forgot to mention that i am not a beginner. I've built my midibox909 which works fine... For now i have not probed navaBD with scope, i just did a visual check, i did not error on the meaning and settlements transistors, capacitors are OK and i controlled all color coded resistors. Because everyone can make mistakes, but i checked, no errors on that side. Tonight i'll do some probes to the scope.
I also checked all my welds.
I consider that it is useless to continue further, as the BD is not perfect. Why go to building the snare and other instruments if the bd is not good? I do not just make simple voltage control, but a real audio test and i tell you, the first test, my BD is not convincing. It looks like a BD909, but it's not like everything!
I am at the beginning of the nava building and i have big doubts about the bd, i suspect there is another bugg. Besides other users of my country tell me they do not have good results to BD with nava sequencer ... Me with trigger test, is not good at all...
I could be wrong, but i'm afraid not ...

there is still buzz on the decay, if i turn the decay down it's clean, if decay is over 0% there is some buzz/noise on each kick.
compared to the old buzz its nothing, but its still there. and if there isn't a lot playing beside the BD it's really noticeable...
anyone else have this? or are your bass drums clean with open decay ?

i checked continuity, traces are cut... tried 2 different M5218L and a M5218AL

@Dr.Knob, how did you trigger it ? with the 5v wire, or with an arduino ?
i tested with the wire during the build, and found the BD to be the hardest to trigger... every other instrument sounded better than the BD... but i have to say i used a horrible little speaker for testing.

The bass drum even with low decay, dirty ... I have a kick that resembles a TR909, but i am still far... I think even by making IC11 correction ago always a mass problem somewhere in the BD circuit.
I compared vs http://www.hexinverter.net/pcb-projects ... nein-kick/
nava does not match

I trigge with yocto trig out simply. The result with hexinverter is correct, it is not with nava BD.
In the worst case, i put the hexhinverter module in place of Nava BD.
There 10mm space between the face of the case and the printed circuit. It's good for extra poti.
By cons, if you also do for the snare drum and others, it is a clone of TR909 will cost me dearly ...

hofmann25 wrote:

decoder303 wrote:about the lvl problem, I couldn't replicate the behaviour why some steps have a higher level sometimes. I only know that, if 1 step in a pattern has higher volume it will stay this way until the whole eeprom gets initialized. Might be a (not perfect but working) work around for people who also have this issue. Seems that somehow some information is "stuck" in the memory and stays there until the init procedure is done?.

Can you explain this initialize procedure a little more decoder?

it's the one described in the manual, initialize the eeprom.

About this i said about the bass drum previously, i had a saturation problem, caused by too wide tolerance of the potentiometer decay. I measured the potentiometers of TR909 and those of nava, those of nava have a very, very, VERY, wider tolerance ... I had to adapt the value of C8 to get a BD of TR909

Is there still a problem with BD and new 1.01a board?