The A-300 is the fifth of Accuphase’s 50th anniversary models and is the successor to the A-250, which has won acclaim around the world. It is a pure Class-A monophonic power amplifier. It combines the latest technology in all circuit and mechanical aspects, and realises the highest performance and sound quality by expanding the Class-A operating range through improved noise characteristics and higher output power, enabling the rich emotion of music to be reproduced.
The ‘Double MCS+ circuit’, which drives two independent power amplifier units with completely identical circuits in parallel, significantly reduces noise components. The input section of the ‘instrumentation amplifier’, which constitutes the entire amplification section, is a double configuration of completely discrete circuits, and together with the exquisite gain distribution with the subsequent stage, an astonishingly high SN ratio has been successfully achieved. The power amplification stage is a 20-parallel push-pull configuration of power MOSFETs, and a powerful power supply section with a newly developed high-efficiency large toroidal transformer and large filtering capacitors achieves high output power and delivers 125W/8Ω, 250W/4Ω, 500W/2Ω and 1,000W/1Ω, exceeding the performance of previous models. Class-A operation and ideal constant-voltage drive are achieved. The protection circuits include MOS FET switches and edge-wise coils for superior sound quality and long-term reliability, while balanced remote sensing greatly improves the damping factor, allowing the speakers to express themselves to the fullest extent. The A-300 has an imposing appearance and marks new history as the pinnacle of power amplifiers.