BA extra parts?

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single_fin
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Joined: Sat Aug 04, 2007 5:29 pm
Location: sydney

BA extra parts?

Post by single_fin »

Hi
I'vve pretyt much finished building a BA OPA2604 Opamp, JLM14 input transformer and 48v psu.
I have two parts left: 10k r and 27k r. Is this correct?

thanks

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Joe Malone
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Post by Joe Malone »

Yes. Both should be for RL. Use 10k with the JLM14 or 27k for OEP262A3C
Joe :-)
JLM Audio
Capturing Audio without Injury

single_fin
Posts: 4
Joined: Sat Aug 04, 2007 5:29 pm
Location: sydney

Post by single_fin »

Thanks Joe.
I have already placed a 10k in RL, and still have one 10k left.

I have placed:
8 x 10k on the PCB in the positions marked '10k'
1 x 10k in RL

I haven't placed anything in the position marked '*10k' on the PCB, near the power switch, as the schematics says this is only if power is greater than 48v, which mine isn't.

Is this all correct?

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Joe Malone
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Post by Joe Malone »

Yes that is fine. It is just a spare for #10k or *10k which you do not need to fit to the PCB.
Joe :-)
JLM Audio
Capturing Audio without Injury

single_fin
Posts: 4
Joined: Sat Aug 04, 2007 5:29 pm
Location: sydney

Post by single_fin »

Joe Malone wrote:Yes that is fine. It is just a spare for #10k or *10k which you do not need to fit to the PCB.
that's disappointing.
i'm not getting the correct voltage measurements, and i was hoping that my problems would be solved by finding out where to put the remaining 10k resistor.
i guess that means there is a solder bridge or a cold solder.

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Joe Malone
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Post by Joe Malone »

Ok if you are getting almost 0v everywhere 24v is shown on the below overlay then the 2 areas in white circles are where most problems occur due to solder shorting adjacent pads.

If you have no volts anywhere make sure you have fitted the 2 yellow wire straps to where the two BD681s are marked on the PCB and that the 10ohm has not burnt or gone open circuit.

Image

As always if you are a stuck with one of our kits send me an email with what voltages you are getting at each opamp pin with and without the opamp fitted to the PCB and send me a few large clear macro on in focus well lit photos of the top and the bottom of the PCB without the opamp fitted and I should have your kit up and going in no time.
Joe :-)
JLM Audio
Capturing Audio without Injury

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