Thanks for the heads up!

Yes it looks like i'm the only one to have had this problem. Twisting the 3rd leg of IC30 out of the pellet is enough to retrieve a 909 clap.
So i do not regret putting IC sockets everywhere.

Can't quite understand how this defect would be looking like on the pcb.
Something is shorted to the GND where it should be not..?
I measured the resistance between BA6110 pin3 and closest pin of R201 and it seems to be connected, also the resistance between BA6110 pin3 and GND...and they also seems to be connected! Probably, if i would see this a day later.. it would be one working BA6110 less in the world.
So the pin3 must be floating (e.g. disconnected) or connected to R201 only (which should not be connected to the GND)?
Well, anyway thanks for info, i would check that before applying power.

ADD:

It seems to be that BA6110 pin3 should be floating (disconnected).
Here is the schematics:

[resize=500]http://i.imgur.com/M1FfJV6.png[/resize]

ADD2:

And here is the actual pcb layout.
Strange, but it's seems like not a defect, but a design flaw if the pin3 should not be connected to GND.

[resize=500]http://i.imgur.com/C8arfBg.png[/resize]

ADD3:

It seems to be some kind of unsolved problem (while it's not in the build manual), here is the other threads which is marked as "solved", but last posts still seems to indicate problems:

viewtopic.php?f=24&t=942&start=20
viewtopic.php?f=24&t=1007&start=10

BA6110 pin3 according to the datasheet is "input bias",

[resize=500]http://i.imgur.com/F30BOR8.png[/resize]

I can guess, it's connected to GND by mistake (and for the reasons unknown some BA6110 works with pin3 to GND connected, and others overheat with the magic smoke out) ... and maybe it should be connected somewhere else (to -VCC... or maybe +VCC?)

I did not see on the shematic, where pin 3 is connected to R201, this said as i do not see this connection on the schematic, i noticed by probing with my multimeter that it was beeeeepppp. Pin 2 must be connected to R201, not pin 3.

That said since i rectified, i have a clap. Before that i had only dirty noise and the BA6110 were destroyed, it isn't a coincidence.
Sorry i had not seen the other threads. Now if others can grill sausages on the BA6110, they will know for it to be right.
Maybe i was not lucky and i had the only one with this defect, it can happen.

I think it's an error in the design, as there is already more than enough BA6110 "grilled"..
Now i desoldered socket and modified pcb (cut the traces around pin3), i think i would also leave it floating for now, until i would figure for sure where it must be connected. When the bipolar transistor base is disconnected, it should be in the "off" state LINK For now it looks like more probably, according to the common sense and the datasheet, in the VCA mode "input bias" should be connected to -VCC, but im not sure how it should be done here.
So waiting now for the comments from the designer, and if he confirm the problem - it should be included in the build manual asap (to avoid frustration and additional demand on BA6110).

ADD:

Look how it was done in the x0x :

[resize=500]http://www.firstpr.com.au/rwi/dfish/TT- ... -drive.png[/resize]

BUT please note, x0x is actually have only GND and +VCC !

ADD2:

quote from HERE :

"pin3 on the ba6110 controls a bias circuit to linearize the input stage. either leaving it floating or connecting it to ground will turn it off, and make it the same as the ba662. i generally like to connec things to ground, just to ensure against stray flux leakage or hum pickup."

But again, remember that the above statement about "connecting it to ground" is correct only for the unipolar power.
So in the nava case - with the bipolar power the "-VCC" is become equivalent of "GND" with unipolar power.
Who is brave enough with more than one BA6110 to connect the pin3 to -VCC and test it? =)
It should give less possible noise compared with leaving it floating.

I totally finished nava, i adjusted the white noise of the clap. And i have the same clap as my MB909. So i had a pcb with a manufacturing defect. Disconnect pin3, fixed the problem permanently.

WARNING: pcb revision 1.01a from 1.01 kit also have this "defect", it was not fixed.

thanks for the info, I didn't have this problem in my first build with rev 1.0l but gonna take care at these 2 builds now that I am finishing soon..

redstorm wrote:WARNING: pcb revision 1.01a from 1.01 kit also have this "defect", it was not fixed.