peskado wrote:Snare Drum

Q43, Q46, Q49
Mixed Collectors and Emitters

changed the collectors and emitters. now tone and snappy doesn´t work

So it seems it isn't advisable to do that.
My working Snare was also damaged due to the swap I put in Sockets and swapped the legs back but the fault stays and I'm not able to locate it.
Since it was suggested by Vincent (E-Lictronic) himself it'd be nice if he'd shed some light into this but instead E-Lictronic is rather not answering questions nor is he providing us with any kind of support for our faulty boards/cirquits! I didn't even get an answer when I asked for replacements because I had a clearly non working Mitsubishi IC and a non working 2SA798!
I'm honestly disappointed and quite frustrated at the moment to be honest!

Electronic components can get damaged by wrong soldering, not that I want to say, that you fried it and that it hasn't already been dead before, but I understand Vincent if he can't offer replacements for every non working transistor/IC. Someone in the re303 forums wrote he soldered at 480°C for example.. Of course it's annoying but after all that's the risk of DIYing.

About the support, he wrote that he is working on the mid tom level problem at the moment, so, if this gets resolved, hopefully the next problem gets addressed. After all this is a DIY project which is pretty new and offered from a small company. If you think about all the bugs of new products from big companies which often take months or even years to get resolved I think we can still be a little bit patient and support each other in the community here.

Yes i think also, i maybe have damaged one of the transistors on overheating.
But i also had killed at first time one of the ic's. It was installed wrong.

I look tomorrow for errors

Did you checked your 909 schematic?

I found the fault in my Snare cirquit after the swapping of transistor legs:
In my case one of the diodes: D58 / D61 was broken!!
After I changed them the Snare worked again.

I would't advise anyone to try and swap the legs of transistors Q43; Q46 and Q49! It damages something in my before working Snare and as it seems I'm not the only one. We should wait until we get an explanation from E-Lictronic about why the circuit differs from the original 909 and what causes the damaging when doing it like in the 909!

D58 and D61 are not even close in the schematics to the affected transistors. I would have expected D64,68 and 67 go busted if. Comparing Original schematic with Nava, the orientation is correct and is what I measure on by board.

Vincent explained why the orientation was wrong and it confirmed my remarks about it.
I'm afraid your busted diodes are most likely an unfortunate coincidence.

jeroenbvo wrote:In the Roland schematic Q43 (NPN) is put in its normal biased mode. In a nutshell it acts like an amplifier. In the Nava circuit it is placed reverse biased, acting more like a switch. The circuit still works fine, however probably has decreased gain. It is most likely the reason why some are complaining that the BD is more quiet: viewtopic.php?f=24&t=889&start=10

EDIT: Transistors on BD seem to be corresponding the original schematics..

The question is, did Vincent do it on purpose for some reason, or is it just an error?

Either way, I think I'll stick to the Roland circuit as the Nava's analog part is a direct copy of it.

e-licktronic wrote:Dear Diyer,

Q43, Q46 and Q49 are in the wrong way. This is a mistake. When we designed Nava SD PCBs, we placed this transistor to act like switches to generate SD envelopes. We had some sound test and it was okay for us but this transistors should act like amplifier.
To solve this issue you need to bend transistors pin 1 and 2 to swap their position in the pad.

Best regards,
e-licktronic

So, you say you have switched yours successfully then?

I switched the legs again because I installed sockets. Now everything seems fine and is working well.
Maybe it was a cold solder joint on my diodes.
It is really easy to miss the solder going through and sticking to the pads because they are so small!