Audio Research - D240 MKII Solid state power amplifier

The Audio Research D240 MkII was the evolution of the original D240, maintaining the solid-state stage philosophy with a musical character close to the valve electronics of the brand.

Audio Research D240 MkII

Main specifications:
Type: Solid-state stereo power amplifier.
Output power: 120 W per channel at 8 Ω.
Drive capability: Stable with 4 Ω loads and capable of delivering high currents.
Frequency response: 20 Hz to 20 kHz.
Damping factor: 170.
Gain: 25.8 dB.
Input sensitivity: 1.6 V.
Signal-to-noise ratio: 106 dB.
Weight: 17.3 kg.
Dimensions: 480 × 133 × 295 mm.

Internal design:
Fully transistorized circuitry.
Input based on selected J-FET and MOS-FET devices.
Output via multiple high-current bipolar transistors.
High-capacity power supply with approximately 180 joules of energy reserve.
Advanced electronic protection against overcurrent, short circuits, and output DC.
Fanless operation, completely silent.

Connectivity:
RCA single-ended inputs.
Inverted RCA inputs.
Balanced XLR inputs.
Bridgeable operation (mono).

The MkII incorporated various refinements of components and internal adjustments to improve:

• Midrange transparency.
• Greater smoothness in highs.
• Better microdynamics.
• Wider soundstage.
• Slightly tighter bass.

Although the nominal power remained the same, many enthusiasts consider the MkII more refined and musical than the first version. These improvements were mainly in sound quality and component selection rather than technical specifications.

Sound signature

The D240 MkII is often described as:
• Warm for a transistor stage.
• Rich and very natural mids.
• Silky highs and not aggressive.
• Excellent spatial recreation.
• Very good pairing with Audio Research tube preamps.
• Relaxed and musical presentation rather than spectacular.