FM Tuner Section
Introduced in 1974 the Yamaha CR-1000 was a high end receiver that was offered in both the U.S. and Japan markets. An audio magazine of the time said: One significant aspect of the CR-1000 is its surprisingly affordable price, considering all the excellent features it offers. This makes the CR-1000 a truly unique proposition in the world of stereo equipment. The CR-1000 is rated at 70 watts per channel. While this is somewhat low for a top end receiver of the time, Yamaha chose to focus less on power output and more on reducing distortion. This concept was incorporated in their tagline “Natural Sound”. Their marketing quote was: By virtually eliminating IM’s (intermodulation distortion) brittle dissonance, we’ve given back to music what it’s been missing. A clear natural richness and brilliant tonality that numbers alone cannot describe. A new purity in sound reproduction. Yamaha claimed that their heritage of producing fine musical instruments such as pianos, organs, guitars, woodwinds, and brass is what drove them to reducing distortion in their audio equipment. The minimalist but handsome wood cabinet was included in the base price of the CR-1000.
One interesting choice that Yamaha’s designers, and I assume marketers, made was to omit AM tuning. They apparently believed that most music lovers would prefer to do without it. So, the CR-1000 is FM only. The CR-1000 controls include a rumble filter with a steep roll-off, switchable treble filter options, a rotary volume control, and a slider for microphone gain control.
The FM tuner is characterized by precise and accurate tuning, complemented by signal strength and tuning meters. With its super-sensitive front end, selective IF amplifier, and advanced FM multiplex demodulator, the CR-1000 has an extremely well designed FM tuning section. Yamaha even introduced a groundbreaking feature in the FM demodulator – the adoption of negative feedback in its transistorized switching circuit. This was a first of its kind feature. This innovative circuit takes part of the switched left-channel and right-channel signals and feeds them back to the original composite signals, effectively reducing distortion in the multiplex demodulator to an impressive low of 0.05%. The FM IF amplifier in the Yamaha CR-1000 is an intricate design that set new standards at the time. Its components include a discrete differential amplifier, two specialized high-gain integrated circuits containing six differential amplifiers, and three ideally phase-linear bi-resonator ceramic filters. These components contribute to the IF amplifier’s exceptional phase linearity and extraordinary band-pass characteristics. The IF amplifier boasts an impressive 80dB selectivity, meaning that your favorite FM station remains undisturbed by neighboring stations. With a capture ratio of 1.0dB and low distortion of 0.15% at 400Hz for FM mono reception (or 0.3% at 400Hz for FM stereo reception), the IF amplifier delivers excellent clarity. Even in challenging urban areas where station jamming is common, the CR-1000 performs at a high level.
Tone Controls
Auto-Touch Tuning
To select your desired FM station, you simply touch the Tuning knob and the built-in AFC (Automatic Frequency Control) circuit shuts itself off for accurate tuning. Once you have “tuned in” the station, this AFC circuit activates as soon as you release the knob, guaranteeing steady, drift-free reception regardless of fluctuations in the power supply voltage or changes in the temperature of the tuner circuitry.