BA BA2 BA4 BAD Dual99v Build Thread

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ylinjohto
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Post by ylinjohto »

[/quote]

Check the BA is fully working with NE5532A and input reg voltage is set to +30 to +36vdc on +V of the opamp sockets. If so you should be able to remove the NE5532A and fit 6 sockets and plug in the discrete opamp. Remember the discrete opamp is only driving the +out so link on dip socket is needed to put -out to 0v so quasi balanced out works.[/quote]

Opamp voltage is 24,1 and I guess that is ok because the Soun Skulptor sk99 is 24v op amp. I just need to clarify what exactly needs to be connected? 0V opamp socket to -output of the line output? Did I understood this correctly?

Thanks!

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Joe Malone
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Post by Joe Malone »

ylinjohto wrote:
Check the BA is fully working with NE5532A and input reg voltage is set to +30 to +36vdc on +V of the opamp sockets. If so you should be able to remove the NE5532A and fit 6 sockets and plug in the discrete opamp. Remember the discrete opamp is only driving the +out so link on dip socket is needed to put -out to 0v so quasi balanced out works.[/quote]

Opamp voltage is 24,1 and I guess that is ok because the Soun Skulptor sk99 is 24v op amp. I just need to clarify what exactly needs to be connected? 0V opamp socket to -output of the line output? Did I understood this correctly?

Thanks![/quote]

If sk99 is +/-24v you want the reg linked over so you have +48v on +V pin as the BA uses this 48v as +/-24v but 0v is referenced to -24v.
Joe :-)
JLM Audio
Capturing Audio without Injury

ylinjohto
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Joined: Mon Sep 02, 2019 7:41 pm

Re: BA BA2 BA4 BAD Dual99v Build Thread

Post by ylinjohto »

Hi, Thank you for information!

I was wondering what is the output impedance of the unit. With JLM14 input tranfo and NE5532A op amp. Does DOA change output impedance?


Cheers

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Joe Malone
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Post by Joe Malone »

ylinjohto wrote:Hi, Thank you for information!

I was wondering what is the output impedance of the unit. With JLM14 input tranfo and NE5532A op amp. Does DOA change output impedance?


Cheers
Balanced output impedance with NE5532A or discrete opamp no output transformer using +out and -out is 102ohm if using 51R or 66ohm if using 33R.
Joe :-)
JLM Audio
Capturing Audio without Injury

Vernois76
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Post by Vernois76 »

Hey Joe, just got my BA kits in today. Just a quick question; on this version 2 you’ve added a trim adjustment for the opamp. Is there a setup necessary for standard 48v supply and 24v opamp?
Thanks for your time!
Gavin

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Joe Malone
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Re: BA BA2 BA4 BAD Dual99v Build Thread

Post by Joe Malone »

Vernois76 wrote:
Mon Jun 08, 2020 3:00 pm
Hey Joe, just got my BA kits in today. Just a quick question; on this version 2 you’ve added a trim adjustment for the opamp. Is there a setup necessary for standard 48v supply and 24v opamp?
Thanks for your time!
Gavin
HI Gavin
For +/-24v opamps you can leave off the BD681 and still link E - C or just wind the trimpot to full. Either works fine. See the Ver 2 schematic under the photo of the new balck Ver 2 pcb for detail.
Joe :-)
JLM Audio
Capturing Audio without Injury

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