The Revox A77 was a semi-professional open-reel tape recorder introduced in 1967 by Willi Studer’s Swiss company Revox. It quickly became one of the most successful and respected tape recorders in the world, renowned for its engineering precision, sonic performance, and reliability. Designed as a bridge between professional studio machines and high-end domestic recorders, the A77 adopted many of the same design philosophies found in Studer’s professional line. Its combination of robust mechanics, electronically regulated performance, and high-fidelity audio reproduction made it a staple in both broadcast and music production environments throughout the late 1960s and 1970s.
The Revox A77 employed a stable three-motor transport system mounted on a die-cast chassis, completely eliminating the need for belts, friction wheels, or slipping couplings. This design ensured long life, minimal wear, and mechanical precision under heavy use. The capstan motor was electronically controlled to maintain constant tape speed, independent of voltage or frequency fluctuations. Electrically actuated servo brakes provided smooth operation and rapid, gentle stopping of reels. The machine could operate in horizontal, vertical, or inclined positions and supported reels up to 26.5 cm in diameter. Its thoughtful mechanical design allowed for extended recording and playback sessions, even with long-play tapes of 1100 metres, yielding up to three hours and twelve minutes of continuous recording at 9.5 cm/s.
The Revox A77’s electronics reflected Revox’s dedication to studio-grade performance. With 54 transistors, 32 diodes, and four silicon rectifiers, its amplifier sections were built on plug-in circuit cards for easy servicing. Separate record and playback electronics, each with independent heads, allowed for genuine off-tape monitoring and accurate alignment of levels, equalisation, and bias. Its wide frequency response, 30 Hz to 20 kHz at 19 cm/s and 30 Hz to 16 kHz at 9.5 cm/s, combined with extremely low distortion and noise figures, positioned the Revox A77 among the best consumer-grade recorders ever made. High-quality REVOX REVODUR heads provided extended life and exceptional magnetic performance, ensuring long-term reliability and consistency.
Each Revox A77 underwent meticulous calibration to meet or exceed Revox’s published minimum specifications. Wow and flutter were measured at better than ±0.08% at 19 cm/s, and signal-to-noise ratios exceeded 60 dB. The amplifier delivered up to 2 × 10 W of music power (2 × 8 W continuous) into 8-ohm speakers, with a total harmonic distortion of less than 1%. Microphone inputs accommodated both low- and high-impedance mics, with selectable sensitivity and individual channel controls for flexible stereo or mono operation. The deck’s logical relay control system provided soft, noise-free switching, while optional remote control expanded its operational flexibility.
Combining precision engineering, Swiss craftsmanship, and professional-level audio performance, the Revox A77 became a benchmark for tape recorders of its era. Its design philosophy influenced countless machines that followed, and its legacy endures among enthusiasts and engineers who continue to value its build quality and sonic excellence.
Features
- Three-motor drive system with electronically regulated capstan motor
- Separate record and playback amplifiers with independent heads
- Full off-tape monitoring capability
- REVODUR long-life magnetic heads
- Plug-in amplifier circuit boards for easy servicing
- Electronically actuated servo brakes
- Dual microphone inputs with independent level control
- Line, microphone, and radio inputs with flexible routing
- Built-in 2 × 10 W stereo amplifier with loudspeaker outputs
- Remote control compatibility
- Horizontal, vertical, or inclined operation
