P3A Problems!

[Josue Guedes]

Common E-I transformers are fine, if you bear in mind they radiate more hum and noise than toroidal, so you may need a larger case to allow spacing the transformer (and power leads) further from the amplifier. I suggest you listen to the amplifier output whilst you carefully (!) move the transformer or just the twisted leads about in the case before bolting down, until you get least noise and then fasten in that position.

If you are looking for best possible sound quality, even low noise levels become important. Otherwise, it doesn't matter what you use. Even cheap SMPS power supplies will work like any power supply if the current and voltages are adequate for peak output needs and grounding is correctly done.

Yes, I will analyze the issues in defining the transformer. Thank you for your opinion.

 

[Josue Guedes]

Which is ???????
For a proper answer Forum members MUST state where they are, best answer depends a lot on that.

Fill your Country/State/City location like most of us did.

It's done!

 

[masood251]

Dear sir
In my circuit vri not work properly to set base bias of Q7 .please solve my problem .

 

[Ian Finch]

Nobody can help solve a problem without knowing the details of your circuit and particularly, how you built it. Is it the original P3A design PCB or something else? Is it posted here on the forum so we can see likely problems?

The problem could be many things so we need to eliminate the obvious differences between the original and your version. Only you know them so give us some details in pictures or references.