Abstract: A stereophonic sound synthesizer system is presented which utilizes a phase splitter in the form of a transformer to develop two oppositely phased audio signals from an applied monaural signal. One of the two oppositely phased signals is applied to a transfer function circuit of the form H(s), which modulates the intensity of a monaural signal as a function of the frequency. The intensity modulated H(s) signal may be applied to an amplifier for subsequent amplification and reproduction. The H(s) signal is also combined with the other of the two oppositely phased signals to produce a difference signal which is the complement of the H(s) signal. The difference signal may be applied to an amplifier for subsequent amplification and reproduction. No differential amplifier is necessary to produce the difference signal because the necessary selective phase opposition of the signals combined in that channel is provided by the use of the oppositely phased transformer output signals.