Accuphase has introduced the A-48S, an enhanced iteration of its acclaimed A-48 power amplifier. This launch signifies a continued dedication to high-performance Class A amplification, succeeding the A-48 after nearly six years in the market.
At first glance, the transition from A-48 to A-48S may seem subtle, as the amplifier upholds its foundational design elements: Class A operation with current feedback, balanced signal detection, instrumentation amplifier topology, MCS+ multiple summing circuit, and MOS-FET relay-based protection systems for overload and short circuit prevention. However, a detailed examination of its specifications indicates that this is more than a mere update.
Accuphase A-48S
A key enhancement is the boost in power output. The original A-48 provided 45W at 8 ohms, while the A-48S elevates this to 50W, maintaining the same doubling effect at lower impedances—ultimately achieving an impressive 400W at 2 ohms. This increase in power is accompanied by a rise in overall weight; the A-48S is nearly 2 kg heavier, yet retains the same physical dimensions.
Additionally, the amplifier features a 6% reduction in noise levels, contributing to a purer sound experience, while the damping factor has improved significantly by 25%, now reaching an outstanding 1000. This exceptional performance is primarily due to the MOS-FET-based output protection, an ultra-short signal path, and Balance Remote Sensing, which captures the feedback signal directly from the speaker terminals in a fully symmetrical manner.
Accuphase A-48S
Aesthetic and functional enhancements have also been incorporated. The A-48S replaces conventional LED indicators with illuminated text, providing a more elegant display of the amplifier’s status. Furthermore, a significant usability improvement is the revamped power meter control. The previous model utilized two buttons to adjust the meter’s display mode, whereas the A-48S features a more user-friendly rotary selector, enabling users to choose from three measurement modes or turn off the indicators entirely.
Accuphase A-48S
The A-48S represents a significant advancement rather than a mere update, featuring increased power, lower noise levels, an enhanced damping factor, and a more sophisticated user interface. By preserving the essential characteristics of Class A amplification while elevating its performance, this amplifier establishes itself as an exceptional option for audiophiles in pursuit of accuracy, strength, and dependability.
Price: $12,500
Accuphase A-48S Features:
- Class A driven 6-parallel push-pull MOS-FET output stage
- Large linear output of 50 W / 8 ohms, 100 W / 4 ohms, 200 W / 2 ohms, 400 W / 1 ohm
- Instrumentation amplifier
- Current feedback amplification topology
- Balanced remote sensing
- MCS+ circuitry
- Large, high-efficiency toroidal transformer
- High capacity 68,000 μF filtering capacitors
- Large speaker terminals connected directly to protection circuitry
- Protection circuitry using MOS-FET switches
- High damping factor of 1,000
- Large, high-sensitivity power meters ranging from –50 dB
- Bi-amping connection and bridged connection switching
- Speaker output protection circuit guards against short-circuiting
- Aluminum hairline finish top plate
- High-carbon cast iron insulator feet with superior damping characteristics
