| 摘要 |
PURPOSE:To increase the through-rate and distortion factor at high frequencies, by giving an input signal to a terminal at ground side of a capacitor for phase margin via a buffer amplifier. CONSTITUTION:An input signal is amplified at basic amplifiers 1, 2, a gain for impedance conversion is outputted via a buffer amplifier 3 of 0dB, negative feedback is made with an impedance Z2 and the characterisitcs such as RIAA are satisfied. On the other hand, the input signal is converted into a low impedance at a buffer amplifier 8 of gain 0dB and an input to the buffer amplifer 3 is given via a capacitor C1 for phase margin. As input signals go to high frequencies, the closed loop gain of a negative feedback amplifier is at 0dB and since the output signal of the basic amplifier 2 and the input signal are at the same potential, the deterioration of the through-rate at high frequencies can be avoided by the capacitor C1. |
