Hi everyone, I am trying to make a Summing Amlifier. I have simulated on computer where it is working correctly, but on real circuit it is showing some mal functioning. I am using OP 27 Op Apmp. The circuit diagram is attached. When I try to add DC voltage to AC sine wave, initially sine wave goes up as required but after even below 1 volt it starts clipping and hence I am not able to rise up the sine wave to about 5 to 8 volts. I am also confused how to use dual supply for +15V and -15V. I think may be this problem is because of dual supply. Please help me. Thank you.