LM358N driving me insane

[arhi]

So your using a 40KHz carrier, but I am wondering what your max modulation frequency is.

good question
no idea, will have to test the circuit as I have no knowledge how to calculate it ... I expect I'll get 6KHz and I believe I do not need more then that..

 

[audioguru]

National Semi's very old and lousy LM324 and LM358 opamps are spec'd and guaranteed with a supply down to only 3.0V and their very new LM4562 is spec'd and guaranteed with a supply down to 5.0V.

 

[arhi]

I have solved the problem .. adding few more resistors (trimmers actually) solved it.

I have added a 7660S so now I'm powering the op-amp's with +-5 .. just to be on the safe side as I'm pretty sure audioguru knows his op-amps

In general, the "Heisenberg" point audioguru gave was pretty clear to where my problem lies. The circuit now works with 5V supply alone, but I have added 7660S afterwards so now the total power is 10V....

now I need to build everything else but other parts should not be a problem as it is all digital from here on

audioguru, I thank you again for the "right to the point" explanation.. I'm learning again it feels good