Description

ACCUPHASE A50V Power AMPLIFIER, boxed
Pure class-A drive delivers high-quality power: 50 watts x 2 into 8 ohms
Output stage with 10 parallel push-pull power MOS-FETs assures power linearity down to ultra-low impedance load, with 400 watts x 2 into 1 ohm
Current feedback circuit topology assures great sound and stable operation
Bridged use of two units possible for four times the output power
Large toroidal “Super Ring” power transformer
The peerless sound of pure class-A – Power MOS-FETs in the output stage with a 10-parallel push-pull configuration perform extremely low output impedance and realize constant-voltage drive for perfect speaker control. Linear power progression ranges from 50 watts into 8 ohms to 400 watts into 1 ohm in stereo operation. Current feedback circuit topology assures great sound and operation stability.

The mono power amplifier M-2000 was widely acclaimed as an impressive blend of performance and sound quality thanks to the realization of two major principles: very low output impedance (Note 1), and constant drive voltage (Note 2).
The A-50V is a stereo power amplifier based on the same design technology as the M-2000. It uses MOS-FET devices selected for their musical qualities which are driven in a no-holds-barred class-A circuit configuration. The amplifier brings out even the most delicate nuances in the source with full authority. This is Accuphase sound at its very best.
Pure class-A operation means that the circuit always draws the same amount of power from the power supply, regardless of the presence or absence of a music signal. It is impervious against external influences and has high stability. The output stage produces considerable amounts of thermal energy, but in the A-50V this is dissipated by extra-large heat sinks for the left and right channels, to prevent the possibility of problems caused by internal heat buildup.
Current feedback topology ensures good phase characteristics in the upper frequency range, combining operation stability with excellent frequency response. The MOS-FET devices in the output stage are renowned for their high reliability paired with favorable sonic properties. The amplifier has outstanding power linearity realized even at extremely low impedance loads, as illustrated by the power rating that extends from 50 watts into 8 ohms to 400 watts into 1 ohm. The muscle for this kind of performance comes from an ultra-efficient Super Ring type toroidal power transformer of massive proportions, complemented by ample filtering capacity.
Balanced inputs shut out externally induced noise. Gold-plating of circuit traces, input/output connectors, and all other major signal-carrying parts ensures total sonic purity. Bridged operation mode turns the unit into a monaural amplifier with even more power.