Revox A 50 with front panel and case from A 78. I got it from a friend. tested on all inputs, I did not notice any defects. sound on both channels without noise and crackling. Great sound on both channels. Optical with signs of use. front panel very well preserved, see pictures.. The Revox A50 (1968–1971) is a vintage integrated amplifier celebrated for its "Swiss neutrality" and robust build quality. As the brand's first transistorized stereo amplifier, it was designed to match the legendary Revox A77 tape recorder and A76 tuner. Performance & Sound Quality Audio Character: Reviewers often note its exceptionally high distortion-free performance from low volumes to rated power. It is described as delivering "sweet" power with excellent dynamics. Output Power: It offers a continuous sine wave power of 2 x 40 Watts at 4–8 ohms, which is sufficient to drive many modern speakers. Phono Stage: Features a high-quality built-in MM phono stage, making it a strong choice for vinyl enthusiasts. Key Features Input Level Controls: A unique front-panel flap hides level pre-reglers for all inputs (except microphone), allowing users to balance volume across different sources like tuners or turntables to prevent jumps when switching. Build & Design: Encased in an elegant wooden cabinet with a brushed aluminum faceplate. Its internal construction uses professional-grade pluggable PC boards for easier servicing. Reproducible Controls: Uses precisely stepped tone regulators rather than standard continuous pots, ensuring exact settings can be replicated.