50Wx2 power amplifier circuit

It is a 50w two-channel power amplifier with preamplification and tone control. LA3160 and its
peripheral components constitute the input prestage. oC1 is the input coupling capacitor, and the island is the high-frequency bypass capacitor, used to filter out high frequencies. interference.
C3 and Rt form a negative feedback network, and R2 and R¨R form a frequency equalization network. C5 is the output coupling capacitor
    . The tone control circuit is composed of VTl, Rs~Rg, G~G, RPl, RP2, etc. Among them, Rs, R, R,
R7, and RPi are bass control networks; R7, R, Island, and RPz are treble control networks. This is a typical negative feedback
tone control circuit. Since this circuit has a large attenuation of the signal, it requires that the transistor VTi should be
a tube with a higher amplification factor, and the Lu value should be greater than 100 to increase the gain of this stage. The collector quiescent current of VTi should be adjusted to 2~
3mA, (adjust Rio), and the load resistance R1 l should not be too small to avoid affecting the dynamic range. Generally,
    the power amplifier circuit part should be 6.8~12kflo in full compliance with the requirements of the typical application circuit. Using ±32V power supply voltage, the output power of each channel
can reach 50w.
    LA3160. It is a dual-channel preamplifier integrated circuit. Its main features are low noise and simple peripheral circuits.
Its typical supply voltage is Vc=9Vo. When the load impedance is 600fl, the open-loop voltage gain is 80dB, the harmonic distortion
is 0.1%, the quiescent current is 4mA, and the input impedance is 100kn. The output voltage is 1.8Vo, the crosstalk is -65d3, and the noise
voltage converted to the input end is 1.25pLVoLA3160 is highly versatile, and preamplifier ICs such as I3A328 and vPC1032 can be directly replaced.