| 摘要 |
PURPOSE:To obtain a circuit of a simple constitution which has a wide range of a sound image, by using a mixing circuit consisting of only resistances, a phase shifting circuit which is common to both left and right channels and a volume control of injection quantity. CONSTITUTION:The left and right signals L and R are supplied 1L and 1R. The signal L is directly increased to mixing resistance networks R1-R6 via buffer TR2L, 2R and the signal R is impressed to mixing resistance networks R1-R6 via a phase inverting TR11. Then betaL=LR5/(R3+R5) and gammaR=gammaR6/(R6+R4) are supplied to positive and opposite phase terminals of mixing amplifiers 9L and 9R respectively. On the other hand, alpha(L-R) which is attenuated (alpha) by the mixing resistance is shifted in terms of its phase by a TR4, a resistance 5 and a capacitor 6 and then attenuated (k) to an optional level by a volume 8 to be taken out via a buffer TR7. As a result, the output is equal to alphak(R-L)=k'(R-L). This output is supplied to the positive phase input terminal of the 9L of an amplification factor K as well as to the opposite phase input terminal of the 9R to obtain -K (beta+k')L-k'R]and -K (gamma+k')R-k'L . Thus a sound image can be increased. |
