ELECTRICAL SIGNAL MIXING APPARATUS

Electrical signal mixing apparatus for recording studio or live performance comprising a plurality of input channels having means for conditioning input signals applied thereto, a plurality of sub-group channels to which the signals from input channels can be selectively assigned, and a pair of output channels which may receive signals directly from the input channels or via the sub-group channels. Routing interconnections between the input, sub-group and output channels are controlled by a microprocessor in dependence on operator selections effected via a single manually operable switch control on each channel. The microprocessor detects destination assignments indicated by operation of the switch on a sub-group or output channel, and act to complete analogue interconnections between input channels and the identified sub-group or output channels upon subsequent actuation of the input channel selector switches. The microprocessor control of routing assignments also allows other functions to be performed, such as storage and retrieval of sets of routing assignments or patches used previously or set up for subsequent use, indication of current routing assignments, muting of selected channels to allow in place solo review of individual input channel signals and the additional possibility of handshake with an external computer for obtaining a video display of the information.