Abstract: In a YC separating filter, a first horizontal chrominance extraction filter extracts frequency components corresponding to components of a color subcarrier in a horizontal direction to produce a first chrominance signal, a vertical chrominance extraction filter extracts frequency components corresponding to components of a color subcarrier in a vertical direction to produce a second chrominance signal, a horizontal and vertical chrominance extraction filter extracts frequency components corresponding to components of a color subcarrier in horizontal and vertical directions to produce a third chrominance signal, a first selector selects one of the first, second and third chrominance signals, a second horizontal chrominance extraction filter having a narrower bandwidth than the first horizontal chrominance extraction filter is provided to receive the selected chrominance signal, and a second selector selects the output of the second horizontal chrominance extraction filter when the first selector selects either

Abstract: In an amplifier circuit, there are provided a preamplifier, a first differential-input amplifier and a second differential-input amplifier. An AC negative feedback path is formed between the output terminal of the preamplifier and the inverting input terminal thereof. The inverting input terminal is connected to a ground via a RC series circuit. An input signal containing a DC voltage component is supplied via the junction of the RC series circuit to the inverting input terminal. A voltage appearing at this junction is applied to both the first and second differential-input amplifiers as a reference voltage.