Hi,
i had been using unity buffer (Tl082) and INAmp(INA129) to amplify some low signal (very low voltage and relatively high noise). Even though the gain in simulation and the circuit test using function generator looks perfect its not in the real case. Both the ICs are quite older and i assume i should go for a modern IC with low input noise. Can someone suggest me a better replacement for the ICs. Or advoce is appreciable.....

NB. the frequency of my input signal is very low (1~20 Hz)

 

So how is the circuit not performing?

Post your circuit.

 

This could be a lot issues combined. I do not know your circuit, or your signal source. So with some reservations I do not think your problems are cured by using some other components. I would look at the common noise sources instead. If your circuit is low power. As a diadnostic measure. Try using some fresh batteries with very short power leads. And see if the noise goes away. It would help if you posted a schematic and a picture of your board. And perhaps words about what your circuit is meant to do