| 摘要 |
PURPOSE:To improve characteristics, by giving gains of extra-low band and DC to negative feedback of amplifiers and mxing anti-phase sound signal components of respective negative feedback circuits in a balanced sound amplifier. CONSTITUTION:Amplifying circuits 16-19 and 36-39 having gains only for DC and extra-low frequencies are inserted into negative feedback circuits of DC amplifiers 13 and 33 which can amplify the range from DC to sound band, and these DC amplifying circuits are so constituted that they are paired and correspond to respective poles of a balanced sound signal. Feedback signals of negative feedback circuits of amplifiers 13 and 33 are mixed with feedback inputs of respective amplifiers to obtain a prescribed amplification degree. Inferior parts of characteristics of amplifiers 13 and 33 are compensated with each other to improve characteristics in respect to the distortion rate and S/N. |
