Yamaha CR-640 Vintage Receiver

Description

The Yamaha CR-640 is a classic late-1970s stereo receiver that combines Yamaha’s understated industrial design with unusually ambitious performance specifications. Produced from approximately 1979 to 1981, the CR-640 occupied the middle of Yamaha’s Natural Sound receiver range and delivered 40 watts per channel into 8 ohms. More importantly, Yamaha designed it to offer extremely low distortion and a neutral tonal character rather than the exaggerated bass-heavy sound associated with some receivers of the period.

The CR-640’s most impressive claim was its 0.02% total harmonic distortion from 20Hz to 20kHz, a specification that Yamaha deliberately matched to its much more expensive flagship receivers. A contemporary High Fidelity review was particularly impressed, noting that the CR-640’s bandwidth and distortion specifications were “precisely the same” as those of Yamaha’s top-of-the-line CR-2040. The reviewer also found that the receiver exceeded its rated power with considerable margin and described its distortion as “virtually nonexistent” at both low and full rated output.

The amplifier section is only part of the CR-640’s appeal. Its tuner is a particularly sophisticated design for a receiver in this price class. Yamaha incorporated AUTO-DX and Auto Blend circuitry that automatically responds to signal strength and interference. With strong stations, the receiver emphasizes low distortion; with weaker signals, it can increase selectivity and blend the stereo signal to improve high-frequency signal-to-noise performance. The contemporary High Fidelity review praised the tuner as “several cuts above the conventional,” finding the DX/blend system especially effective with weak stereo broadcasts.

The CR-640 also offers an unusually flexible preamplifier section. Inputs include phono, auxiliary and tape connections, while independent recording/source selection makes it possible to record one source while listening to another. Yamaha included bass and treble controls, a variable loudness control, and filtering facilities. The phono stage was singled out by High Fidelity, which called it “eminently quiet,” while the reviewer also praised the flexibility of the preamplifier and the usefulness of the tape-recording controls.

Sonically, the CR-640 embodies Yamaha’s Natural Sound philosophy: clean, neutral and relatively uncolored. Some listeners accustomed to warmer vintage receivers may initially perceive it as somewhat lean, but that neutrality can be an advantage with speakers that already have a full, balanced presentation. A modern vintage-audio assessment describes the CR-640 as a “clean and accurate” representation of the source, while a restored example was described by its owner as “clear and punchy with surprisingly strong bass.”

Its understated silver faceplate, three-tier control layout, analog tuning scale and wood cabinet have also made the CR-640 increasingly desirable among vintage-audio enthusiasts. The principal caution with a used example is age: lamps commonly require replacement, and the receiver uses integrated power amplifier modules that can be difficult to source if they fail. A properly serviced CR-640, however, remains an excellent vintage receiver—particularly for listeners who value accurate sound, strong FM performance and classic Yamaha styling.

Product Specifications

• Type: AM/FM stereo receiver
• Years: Approximately 1979–1981
• Power output: 40 watts/channel into 8 ohms
• Frequency response: 20Hz–20kHz
• Total harmonic distortion: 0.02%
• Damping factor: 40
• Phono input sensitivity: 2.5mV
• Line input sensitivity: 120mV
• Signal-to-noise ratio: 78dB phono; 86dB line
• Minimum speaker impedance: 4 ohms
• FM tuning range: 88–108MHz (approximately)
• AM/MW tuning: Included
• FM features: AUTO-DX and Auto Blend
• Controls: Bass, treble, variable loudness, high/low filters
• Inputs: Phono, AUX, tape
• Recording: Independent Rec Out selector
• Speaker outputs: Two speaker systems
• Dimensions: Approximately 20″ W × 6.6″ H × 15.25″ D
• Weight: Approximately 27.8 lbs.
• Cabinet: Simulated ebony/wood-grain finish