Abstract: This invention provides a matrix switcher apparatus adapted to arbitrarily distribute signals in a plurality of input channels to a plurality of output channels. The matrix switcher apparatus includes a cross point matrix adapted for connecting one matrix switcher unit to any other matrix switcher unit or units to carry out expansion of input/output, and input and output terminals expandable up to a predetermined maximum number of channels.

Abstract: A cross fader for editing audio signals has first and second bus lines, each including a plurality of channel signal lines and first and second plural selecting and indicating switches, each corresponding to the signal line of the first and second bus lines, for selecting the corresponding signal line responsive to the switching operation and for visually indicating the selected modes of the signal line. A fader mixes signals from the first and second selecting and indicating switches for outputting a mixed signal and for variably controlling the mixing ratio of the signals according to the movement of an operation knob. The first and second selecting and indicating switches are arranged so that said first and second switches are related with one end and the other end of the movement of the operation knob, respectively.