Self configuring output stages of precision amplifiers that remain linear when operating into a load that may have a ground reference below the amplifier ground reference, that maintain full amplifier gain while approaching zero output, and that can provide a zero output even when operating into a load that may have a ground reference below the amplifier ground reference, that has a self configuring output stage operable with either a mid-rail or ground reference below amplifier ground, and which maintain a high output impedance when not selected even when the output is above the amplifier supply voltage, or when not powered, thereby allowing amplifier outputs from un-powered amplifiers or amplifiers operating at lower supply voltages to be connected in common for multiplexing to a common load.