Question about Brian's LM3785 Rev.C components (Rz and Cz)

[maurycy]

Hi,

I am building Brian's LM3785 stereo kit (two amp boards, one power supply board). I will be using only four diodes and two capacitors on the power supply board because the amp will be powered by a CT transformer.

My question is: Do I need the 0.1 uF Cz capacitor and 2.7 ohm Rz resistor on the amp board? Brian's PDF with information says that they are optional.

Thanks,
Alex

[BrianGT]

Originally posted by maurycy
Hi,

I am building Brian's LM3785 stereo kit (two amp boards, one power supply board). I will be using only four diodes and two capacitors on the power supply board because the amp will be powered by a CT transformer.

My question is: Do I need the 0.1 uF Cz capacitor and 2.7 ohm Rz resistor on the amp board? Brian's PDF with information says that they are optional.

Thanks,
Alex

They are for the optional zobel network. You don't really need them, but I tend to recommend them if you aren't sure about the load that you are driving with the amp.

Best of luck with your project,

--
Brian

[catalina3899]

I tested both with and without and have concluded that with the optional componets, bass response was improved.

Jim

[maurycy]

Thanks guys. I can't wait till I am off work and can go back to the project.

Alex