Two Stage Phono Pre-Amplifier with Very Accurate RIAA Response Curve
To produce a pre-amplifier with accurate RIAA response, this circuit use two stages of amplifier. This circuit is more complex than single op-amp RIAA pre-amp, but the performance is excellent in terms of accurate frequency response. Here is the schematic diagram of the circuit.
The circuit uses LM833 high performance op-amp from National Semiconductor, giving the best performace of 0.1 dB response curve error, compared to the standard RIAA curve. [Circuit’s schematic diagram source: National Semiconductor Application Notes]