Accuphase A-48S

Name: A-48S
Brand: Accuphase
Price: 11490.0 EUR
Availability: InStoreOnly

Accuphase A-48S - Class A Stereo Power Amplifier

The Accuphase A-48S is a Class A stereo power amplifier that represents the culmination of decades of expertise in high-end amplifier design. As the successor to the A-48 model, the A-48S incorporates a multitude of cutting-edge technologies to deliver exceptional performance.

Impressive Linear Power

The output stage of the A-48S uses a parallel push-pull configuration with 6 power MOS-FET transistors operating in pure Class A. This architecture allows it to deliver remarkable linear power of 50 W into 8 ohms, 100 W into 4 ohms, 200 W into 2 Ω, and even 400 W into 1 Ω (with musical signals). The linear power progression according to load impedance ensures optimal driving of any type of speaker.

Extremely Low Noise Level and High Damping Factor

Thanks to an ideal gain distribution and sophisticated techniques, the A-48S manages to reduce noise levels by 6% compared to conventional models. The signal-to-noise ratio thus reaches the exceptional value of 118 dB (A-weighted), ensuring great signal purity.

With an extremely high damping factor of 1000, the A-48S exerts total control over the back electromotive forces of the speakers. This allows you to get the best out of any speaker in terms of dynamics, precision, and transparency.

Fully Symmetrical Input Stage

The input stage of the A-48S is configured as an instrumentation amplifier. This approach allows for fully symmetrical signal paths from the input to the final amplification stage. The input impedance is equalized between the + and - sides for excellent rejection of external noise.

MCS+ Circuit to Reduce Noise Floor

By arranging the voltage amplification stage in a two-parallel-circuit configuration, the MCS+ (Multiple Circuit Summing-up) circuit theoretically reduces the noise floor by about 30%. The result is a sound of great purity, without any veil.

Current Feedback Amplification Topology

The A-48S uses a current feedback amplification topology that offers exceptional performance in high frequencies. The frequency characteristics are minimally impacted by gain changes, resulting in natural and dynamic speaker driving.

Oversized Toroidal Transformer

The power supply of the A-48S relies on a large, high-efficiency toroidal transformer. Combined with 68,000 μF filtering capacitors, it provides a considerable energy reserve to power the output stage without any restriction.

Mono-Block Construction for Perfect Channel Separation

The A-48S adopts a mono-block construction with completely separate power supplies and amplification circuits for the left and right channels. This design eliminates any crosstalk and interference between the two channels for perfectly defined stereophonic reproduction.

Superior Quality Components

Each component of the A-48S has been meticulously selected for its performance and reliability. The MOS-FET transistors, metal film resistors, audiophile capacitors, and epoxy printed circuit boards ensure optimal sound quality and long-lasting durability.

A Rigid Chassis and Anti-Vibration Feet

The chassis of the A-48S is made from thick steel for maximum rigidity and stability. The top cover in brushed aluminum adds a touch of elegance. The high-carbon cast iron feet provide excellent vibration damping properties.

What are the main advantages of the A-48S’s output stage?

The output stage of the A-48S uses a parallel push-pull configuration with 6 MOS-FET transistors operating in pure class A. This allows for high power, very low output impedance, and linear power progression according to the load. The A-48S can thus drive any type of speaker with ease and precision, even the most demanding ones.

What are the characteristics of the A-48S’s input stage?

The input stage of the A-48S is configured as an instrumentation amplifier with fully symmetrical circuits. The input impedance is balanced between the positive and negative sides, ensuring excellent rejection of noise and external interference. This is the ideal configuration for a high-end audio amplifier.

Why is the high damping factor of the A-48S important?

With a damping factor of 1000, the A-48S exerts extremely tight control over speaker movements. This results in great precision in impulse response, excellent dynamics, and transparent reproduction of the finest details. The speakers thus deliver their full potential without any limitations.

What are the connection possibilities of the A-48S?

The A-48S offers multiple connection options for easy integration into any hi-fi system. It features balanced (XLR) and unbalanced (RCA) inputs, two pairs of speaker outputs for bi-amplification, and allows for bridged (mono) operation to double the power. You can use it in the most varied configurations.

Why is the mono-block construction of the A-48S beneficial?

The mono-block construction of the A-48S, with completely separate power supplies and amplification circuits for the left and right channels, offers several advantages. It eliminates any interference or crosstalk between channels, optimizes performance and stereo reproduction accuracy, and enhances the power capacity of each channel for breathtaking dynamics.

What the press says

Announced alongside the E-800S, Accuphase's new A-48S stereo power amplifier is more of a minor update to the A-48 than a true evolution. This aligns well with the philosophy of the Japanese manufacturer, which continuously refines its well-established designs with small, incremental improvements. With the A-48S, Accuphase delivers a product that is slightly more powerful and technically advanced than its predecessor.

Automatically translated — Show original (French)

Annoncé en même temps que le E-800S, le nouvel amplificateur de puissance stéréo A-48S d’Accuphase est davantage une petite mise à jour du A-48 qu’une réelle évolution. Cela suit assez bien la philosophie du constructeur japonais, qui améliore sans cesse, par petites touches, des architectures déjà bien rodées. Avec ce A-48S, Accuphase livre ainsi un produit légèrement plus puissant et plus technique que son prédécesseur.