1. LM1458M Substitution Conclusion Direct substitution is not viable. The LM1458M and the ADA4062-2ARZ-RL differ fundamentally in core performance. The ADA4062 is a JFET-input operational amplifier featuring extremely low input bias current (2 pA vs. 80 nA, a difference of four orders of magnitude) and lower input offset voltage (750 µV vs. 2 mV). These characteristics make it suitable for applications highly sensitive to input current, such as high-impedance sensor interfaces and precision integrator circuits. In contrast, the LM1458M is a standard bipolar-input op-amp whose high input bias current would introduce unacceptable error in such applications. Furthermore, the ADA4062 supports a more flexible single-supply or wide supply range of 8V to 36V, whereas the LM1458M requires a dual supply of ±18V (or a total of 36V), resulting in poor supply compatibility. The significant disparity in slew rate (3.3V/µs vs. 0.5V/µs) also means the LM1458M cannot meet the potential fast signal response requirements of the original design. Unless the application circuit is exceptionally tolerant of input impedance, precision, and supply requirements, substitution will lead to severe performance degradation or circuit failure.