electronic input selector

In most audio amplifiers the input selector switch is mounted on the front panel of the equipment, whilst the input sockets are mounted on the back panel. This means that the input signal leads must be routed all the way from the back panel to the front panel before going off to the actual amplifier input, thus increasing the possibility of hum and noise pickup crosstalk. The transistor input selector described here switches the signals at the rear of the amplifier close to the input sockets. Switching is still controlled from the front panel switch, but audio signals no longer flow through it.