A circuit is presented which includes a first amplifier having an input, a transmission line having first and second ends. The first end of the transmission line is coupled to an input of the first amplifier and a plurality of channels. Each channel includes a plurality of resonators arranged to read out a plurality of qubits, respectively and a readout line arranged to receive read out signals from the plurality of resonators. The readout line of each channel is coupled to the transmission line and each channel is configured to output a respective signal in a respective frequency band which is different from frequency bands of other channels in the plurality of channels.