BA BA2 BA4 BAD Dual99v Build Thread

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papiblu
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby papiblu » Wed Oct 25, 2017 11:09 am

Hi, Im building a BA with JLM14, JLM99v and JLM111DC
I got a few questions, (I tried to find in the Thread or the Joe Quotes but I wasn't lucky), here it goes:

-in the OPAMP zone of the pcb, the V2 version got 2 resistors at 33k that reading the thread and watching the photos are 51ohms,
which value is correct??

-the 111 i got and the photo on the web are different, how should I wire it to do a 1:2 and get those extra 6db??

-I did the 4 and 7 pin link in the IC holes, is it necessary when you got an output transformer?

thank you very much!

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Joe Malone
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Joe Malone » Wed Oct 25, 2017 1:42 pm

papiblu wrote:Hi, Im building a BA with JLM14, JLM99v and JLM111DC
I got a few questions, (I tried to find in the Thread or the Joe Quotes but I wasn't lucky), here it goes:

-in the OPAMP zone of the pcb, the V2 version got 2 resistors at 33k that reading the thread and watching the photos are 51ohms,
which value is correct??

I think you mean 33R. 33R gives a flatter low end response when using latest Green or Red top JLM111DC transformers and is recommended for all new builds.

-the 111 i got and the photo on the web are different, how should I wire it to do a 1:2 and get those extra 6db??

The numbering on JLM111DC has never changed in over decade. The three winding a identical so any can be used as primary or secondary.
e.g. 1:2 use +1 to out, -1 to 0v for primary. +2 to XLR pin 2, -3 to XLR pin 3, Join -2 to +3 with wire link. PCB top transformers have solder pads on eitherside. You can use either pad with the right number on it.

-I did the 4 and 7 pin link in the IC holes, is it necessary when you got an output transformer?
thank you very much!

No as -out isn't used with output transformer fitted
Joe :-)
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Ayguid
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Ayguid » Tue Nov 07, 2017 4:44 pm

Hi Joe. Im having problems with a couple of BAD(6x) im building. Im using ne5532, so im fitting the bd681 reg and the 36v zener. But im getting 44v at the opamps V+. and 22V in the 1/2 rail. At first i thought it was the reg or zeners. But i tested the zeners and reg outside the board and they work ok. I even took out the reg and zener from another Baby animal i have, that i know has ok voltages,,,and fitted them to the BAD boards...still same issues.
Rgain1 and rgain 2 not fitted. But i think that has no effect on this right? If you could help me find the problem, i would be very greatfull.
Thx
Guido.

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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Joe Malone » Tue Nov 07, 2017 4:57 pm

Ayguid wrote:Hi Joe. Im having problems with a couple of BAD(6x) im building. Im using ne5532, so im fitting the bd681 reg and the 36v zener. But im getting 44v at the opamps V+. and 22V in the 1/2 rail. At first i thought it was the reg or zeners. But i tested the zeners and reg outside the board and they work ok. I even took out the reg and zener from another Baby animal i have, that i know has ok voltages,,,and fitted them to the BAD boards...still same issues.
Rgain1 and rgain 2 not fitted. But i think that has no effect on this right? If you could help me find the problem, i would be very greatfull.
Thx
Guido.


HI Guido
Email me some clear well lit photos of the BAD pcbs top and bottom with parts fitted for me to check over so I can see what is going on for you.

What power supply are you using?

And how did you test that the zeners are 36v ones?

What numbers are written on the zeners?
Joe :-)

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Ayguid
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Ayguid » Tue Nov 07, 2017 5:07 pm

Email sent.

Ayguid
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Ayguid » Tue Nov 07, 2017 5:10 pm

They say 36x, I tested them to see if they measured the same voltage drop that the ones i know work have.

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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Joe Malone » Tue Nov 07, 2017 9:09 pm

Ayguid wrote:They say 36x, I tested them to see if they measured the same voltage drop that the ones i know work have.


HI Guido
I had forgot since we never fit zeners to BAD here that the BAD pcb needs a wire from the Zener cathode (pad next to Z2) to a 0v ground plane solder pad to pull the Zener to 0v then it will work properly. Try this and let me know if that works or not.
Joe :-)

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Dais3
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Dais3 » Thu May 17, 2018 5:01 am

Hi Joe
I built a couple of baby animals last year without an output transformer using the JLM op amp and they do sound fantastic.
I recently acquired a few LUndahl LL1517 out put transformers. I'm considering adding two of these wired 1:2 to give a 6dB boost to the output.
The 1517 is speced to work optimally with a very low source impedance. Do you think these would work well with the baby animal?
Many thanks
Dave

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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Joe Malone » Thu May 17, 2018 7:49 am

Dais3 wrote:Hi Joe
I built a couple of baby animals last year without an output transformer using the JLM op amp and they do sound fantastic.
I recently acquired a few LUndahl LL1517 out put transformers. I'm considering adding two of these wired 1:2 to give a 6dB boost to the output.
The 1517 is speced to work optimally with a very low source impedance. Do you think these would work well with the baby animal?
Many thanks
Dave


HI Dave yes that will work great as the BA has low output impedance of 51 ohm on green pcb and 33 ohm on black pcb.

You can change the output impedance to more or less by changing one resistor on the BA pcb.
Joe :-)

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Dais3
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Dais3 » Thu May 17, 2018 8:31 pm

Great thanks Joe. That R13 and R16 yes? Is there any minimum value you would suggest on those?
Thanks

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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Joe Malone » Sun May 20, 2018 8:26 pm

Dais3 wrote:Great thanks Joe. That R13 and R16 yes? Is there any minimum value you would suggest on those?
Thanks


R13 is the only resistor that needs adjusting sometimes to maximise the low end of the output transformer as the primary return should go to 0v not -out. To small a value can put a bump in the low end and to larger can roll off the low end early. 33R is perfect for our JLM111DC and compact versions.

Use Rightmark RMAA to do a freq sweep to see how the low end looks before changing R13. Lowest value usually would be about 10R.
Joe :-)

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Camsown
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Camsown » Sun May 19, 2019 4:13 pm

I'm currently building a BAD Dual99v module and I've only just noticed that R7 is left blank. I've already added R7 to the board and before I cut it off, I just wanted to understand what would happen if I left it in place?

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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Joe Malone » Mon May 20, 2019 10:03 pm

Camsown wrote:I'm currently building a BAD Dual99v module and I've only just noticed that R7 is left blank. I've already added R7 to the board and before I cut it off, I just wanted to understand what would happen if I left it in place?


Doesn't matter if R7 is fitted or not. Just make sure you fit the E to C wire link for 48v phantom to work.
Joe :-)

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Camsown
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Camsown » Tue May 21, 2019 9:26 pm

Joe Malone wrote:Doesn't matter if R7 is fitted or not. Just make sure you fit the E to C wire link for 48v phantom to work.

Thanks Joe. Picked up on the E to C thanks to the errata notes.
:D

Camsown
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Postby Camsown » Sat May 25, 2019 4:47 pm

Hi Joe.

On the Dual99v kits, where do I attach the phantom power led? Do I just attach it to the legs of the 48v toggle?

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