| 摘要 |
PURPOSE:To improve the channel separation, by operating an amplifying circuit of a channel as a constant load of a positive power supply and an amplifying circuit of other channel as a constant current load of a negative power supply. CONSTITUTION:Amplifying circuits 1, 2 amplifying mutually independently a stereo signal and having a dual (positive/negative) power supply are provided. A current is applied from constant current sources I1a-I3a to active elements Q1a, Q2a, Q5a and Q6a constituting the amplifying circuit 1. Thus, the circuit 1 is the constant current load when viewed from a negative power supply -VCC. The other amplifying circuit 2 is constituted as the constant current load when viewed from a positive power supply +VCC similarly. Thus, since one channel is not susceptible to any effect at all even if one power supply is fluctuated because of the other channel signal, the channel separation is improved. |
