Audio-GD - MASTER 10 mk3 - Class AB - Balanced Integrated Amplifier

ACSS Amplification – Pure, Balanced, and Transparent

The Master 10 Mk3 features a true balanced design using our proprietary ACSS (Amplifier Circuit with Single Stage) technology, achieving a level of purity and neutrality rarely found in high-end amplifiers. Even standard XLR connections benefit from the newest ACSS improvements, making their performance comparable to the direct ACSS connection.

Simplicity Meets Precision

Despite its sophistication, ACSS is one of the simplest high-performance amplifier designs in the world. Unlike conventional amplifiers, which often use multiple voltage gain stages, the Master 10 Mk3 requires only a single voltage gain stage, operating in current-mode ACSS. This ultra-short, ultra-simple signal path ensures:

• Neutral, uncolored sound
• Preserved dynamics and detail
• Minimal distortion

All gain and pre-driver stages operate in Class A, while the output transistors work at a high idle current. The diamond-cross output stage eliminates switch distortion, achieving the sonic benefits of Class A without excessive heat or energy loss.

Non-Feedback Design for True Musicality

ACSS uses a fully discrete, non-feedback design. While traditional global-feedback circuits may measure better on paper, they often compromise musicality. ACSS bypasses this trade-off, delivering:

• Extremely low distortion
• High linearity
• Dynamic, detailed, and natural sound
• No harshness or artificial brightness

All gain occurs in current, enabled by a unique open-loop multiple-output current mirror, providing exceptional precision and ultra-low distortion. The signal path remains fully balanced, and every transistor works in Class A mode.

Precision Volume Control Without Compromise

Unlike conventional analog amplifiers, where a volume potentiometer in the input stage reduces the signal and can degrade sound quality, the Master 10 Mk3 takes a radically different approach. Traditional volume pots—even high-end ones—can lose detail, unbalance channels, distort the soundstage, and worsen signal-to-noise ratio.

I/V Conversion Volume Control

In the Master 10 Mk3, volume is managed through a passive I/V (current-to-voltage) conversion at the output of the ACSS amplifier. Here, the signal is still a current signal, not voltage, ensuring that the volume control does not degrade sound quality at any level. This approach keeps the frequency response flat and preserves every detail, similar to the passive I/V conversion used in high-end R-2R DACs.

After volume control, the signal flows into four channels of diamond non-feedback output stages, providing ultra-low output impedance to drive your speakers with complete authority.

Four-Channel Balanced Precision

True balanced operation requires perfectly matched four-channel control. Any imbalance between channels—especially under temperature changes—can cause distortion and degraded performance, negating the advantages of a balanced design. The Master 10 Mk3 ensures precision through four-channel digitally controlled relay-based volume circuits, using high-quality DALE resistors to maintain exact channel matching.

Users can select from 99-step exponential volume control, allowing smooth, precise adjustments. While the relays engage during volume changes, any minor switching sound is transient and disappears immediately after adjustment, ensuring pure, uninterrupted musicality.

Powerhouse Engineering Inside

At the heart of the Master 10 Mk3 lies a massive, high-current power supply designed to deliver effortless control and musical authority. Built with an abundance of high-power components, this robust supply ensures vigorous current output capable of driving even the most demanding loudspeakers with ease.

• Diamond Non-Feedback Output Stage
  The Master 10 Mk3 employs four channels of diamond non-feedback output stages, utilizing 24 ON Semiconductor transistors. Each transistor is rated at 15A / 230W, guaranteeing explosive dynamics, speed, and precision.
• Exceptional Energy Storage
  With a total capacitance of 140,000μF, the amplifier maintains rock-solid stability under all musical conditions, ensuring effortless delivery of both delicate detail and massive dynamic swings.
• Dual Transformer Design
  Two custom-wound transformers with a combined power of 1500W provide a limitless energy reserve, giving the Master 10 Mk3 the authority to control any speaker load with confidence.

The result is an integrated amplifier with unshakable power, transparency, and refinement a true reference for those who demand the very best in sound reproduction.

Precision Engineering for Pure Sound

The Master 10 Mk3 is built with a heavyweight all-aluminum alloy chassis, meticulously designed to minimize eddy currents from the transformers and prevent interference with the circuitry. Inside, the amplifier is divided into two separate sections using aluminum partitions, ensuring optimal isolation between the ACSS components, output stages, and transformers. Even the AC power cable is routed through a copper shielding channel from back to front for the cleanest possible power delivery.

Vibration Control for Pristine Playback

Every detail in the Master 10 Mk3 is designed to preserve musical integrity. Each channel’s gain stage sits on a 5mm-thick aluminum plate, which balances heat between the cooler and hotter parts of the amplifier. More importantly, all transistors are carefully mounted to the aluminum plate to minimize vibration, preventing any unwanted resonance that could degrade sound quality.

Our extensive testing confirms the benefits: with the aluminum plates in place, the Master 10 Mk3 reproduces clearer detail and smoother sound, with less harshness compared to a design without vibration control.