Accuphase A-48S Class-A Stereo Power Amplifier
The Accuphase A-48S is a high-performance Class-A stereo power amplifier, representing the fifth generation of this series. Building upon its predecessor, the A-48, the A-48S delivers enhanced power output, improved drive capability, and superior noise suppression. With a rated output of 50W into 8 ohms and a robust 200W into 2 ohms, it provides exceptional dynamic range and effortlessly drives a variety of speakers. The damping factor has been increased by 25% to 1000, matching top-tier models and ensuring precise speaker control. Additionally, the noise level is reduced by 6%, achieving a remarkable signal-to-noise ratio of 118dB for a clearer and more immersive audio experience.
The A-48S features an advanced mono-block construction with independent power amplifier engines for the left and right channels, supported by a custom-made high-efficiency toroidal transformer and large 68,000μF filtering capacitors. Its amplification stage incorporates a six-parallel push-pull MOS-FET configuration, reducing output impedance and ensuring reliable performance under various conditions. The balanced signal input section employs instrumentation amplifier principles to minimize external noise, further enhancing audio purity.
Designed for both performance and user convenience, the A-48S includes high-sensitivity analog meters, a front-panel gain selector with four levels, and dual speaker terminals for added flexibility. Safety and reliability are bolstered with advanced protection circuits using photo-couplers and temperature sensors, safeguarding the amplifier during operation. This meticulous attention to detail ensures the A-48S delivers the nuanced Class-A sound quality Accuphase is renowned for, capturing every subtle musical expression with precision and emotion.
Specification
Power Output: 50W/8Ω; 100W/4Ω; 200W/2Ω
Damping Factor: 1000
Signal-to-Noise Ratio: 118dB
Dimensions: Width 465mm; Height 211mm; Depth 464mm
Weight: 34.8kg
Amplification Stage: 6-parallel push-pull MOS-FET configuration
Transformer: High-efficiency toroidal transformer
Filtering Capacitors: 68,000μF (x2)
Gain Levels: Max; -3dB; -6dB; -12dB
Noise Reduction: 6% lower noise than A-48
Speaker Terminals: Dual independent terminals
Protection Circuit: Photo-coupler-based with temperature sensors