A multichannel record disc reproducing apparatus has a pickup cartridge for picking up signals from a multichannel record disc. A multiplexed signal was recorded on the disc by first multiplexing direct wave signals and angle-modulated wave signals which are recorded on opposite groove walls. Filters separate the picked up multiplexed signal into the direct wave signal and the angle-modulated wave signal. A demodulates circuit for demodulating the angle-modulated wave signal, thus separated. A matrix circuit separates the signals to obtain a plurality of separate channels from the direct wave signals and the demodulated signals. A circuit in a stage preceding the demodulator removes substantially all components of the higher harmonics at the carrier wave center frequency, which carrier was used for angle-modulating the original signal.