discornixer

discomixer This mixer is a typical example of the way modern components can, and do, simplify the realization of good quality audio circuits. In the given configuration it is eminently suitable for use as a discomixer, but the number of input channels can easily be enlarged. As can be seen in figure 1, in its basic form the mixer has four input chan- nels. These could, for instance, serve as inputs for a microphone, stereo pick-up, and cassette player or tape recorder. The power supply has been kept as simple as possible; if it proves difficult to obtain the XR4195 regulator IC, it may be replaced by a combination of a 78L15 and 79L15. The transformer is preferably of the PCB type to keep the mixer as compact as possible. The values of C1and R1are depen- dent on the type of microphone used. 7-61 If this is a high-impedance type, the values should be 470 nF and 22 Id2 respectively, whereas with low- impedance types, 10 I.4F and 680 Q are required. Unfortunately, miniature bipolar...