Preamplifier using OP37

As shown in Figure 3-5, this circuit uses OP37 to form a multi-functional preamplifier circuit. OP37 is
an integrated operational amplifier circuit with better performance than NE5534. Table 3-3 lists the parameter comparison between the two. From the comparison in the table, we can see that
OP37 has higher conversion speed, higher open-loop gain, lower noise voltage and higher common-mode rejection ratio, and is
a veritable "King of Op Amp" o
    Icl It forms an electromagnetic record player input equalization circuit, which meets the requirements of the RIAA standard. I bar forms a line amplifier,
which provides inputs for turntables, tape recorders, microphones and lines . The input is selected by switch SA. The tone control circuit with high, medium and bass control is composed
    of IC3, RP2~RP4 and their resistor-capacitor
network.     The power supply of the circuit uses a 15V positive and negative symmetrical power supply to improve the working performance of the circuit. The circuit components use high-quality resistor-
capacitor components to ensure its technical specifications.