The Phono Preamp has a precise RIAA equalization curve and is very quiet and the best audio amplifier circuit you will ever get. Most of the people are building this secret circuit and do sales in the local market. Performance wise this will not disappoint you.
The entire circuit is controlled by the op amp of NE5532. But you can use any operational amplifier IC. They also work. But the NE5532 is the best one for the maximum performance.
The NE5532 is a low noise and operational amplifier IC it can handle the audio signals much faster than any other op amp.
Replacement of NE5532 Op-amp IC
The noise of the amplifier stage is reduced above the 2Khz by using the passive filter circuit. The replacement of NE5532 is OPA2134, LM4562, and OPA2134s.
The phono preamp is the capacitive loading on the op amp output at higher frequency. And the op amps can handle 600 ohms (750 or 820 ohms) load easily.
In the first circuit section a 10K resistor is in series with the capacitor. So the capacitive load should not be considered.Â
Circuit Diagram
Volume level and frequency
Through the visual analyser checking its show the signal taken from the fm radio tuner. The sound starts to get quieter above 15kHz. And a 19kHz pilot tone used for a special purpose in FM radio. The signal was captured over a long time of 2 hours. And showing the loudest volume at different frequencies. So the circuit can do everything above 15kHz frequency.
Different types of music have variations. Did Not use any adjustments on the signal we received on it.
