Equalizer circuit, high-fidelity playback amplifier and high fidelity playback amplifier and acoustic characteristic correction circuit in with the equalizer circuit

摘要

PURPOSE:To eliminate the phase distortion and to bring the reproduced sound close to the original sound by forming an equalizer having a specific characteristic against an input sound signal by combining a resistor and an inductor. CONSTITUTION:An HPF is formed by a series circuit of a resistor R2L, and inductors L2, R3L and L3L, and an HPL is formed by series circuit of L2R, R2R and R3R. An LPF is formed by a parallel circuit of L1L and R1L and a parallel circuit of L1R and R1R. R1 and L1, R2 and L2, and R3 and L3 correct a low frequency, an intermediate frequency and a high frequency, respectively, and by advancing relatively a phase of 1kHz-5kHz of an input sound signal, the perspective is enhanced, and in the case of =1kHz, the phase is delayed by following a drop of the frequency response, and also, a circuit constant is selected so as to become an opposite characteristic to the peak of resonance of a reproduced sound field. According to this constitution, a phase difference can be eliminated, and a reproduced sound can be brought close to the natural sound. Also, it further approaches to the natural sound by adding a high fidelity reproducing amplifier and an acoustic characteristic correcting circuit.