Power amplifiers stereo — Analog Domain The Athene

The Athene is a high-power amplifier from the DX9 range of Analog Domain Audio GmbH, the company Angel Despotov founded in Munich in early 2010 and which now works from Taufkirchen in Germany. Four models make up the DX9 range, and the Athene ranks third by output, above the Calysto and the Artemis. It is built in the larger M4 chassis, and Analog Domain says it can drive any channel of a high-performance split system.

Key specs that matter

Analog Domain rates peak output at 2 kW into 8 ohm and 4 kW into 4 ohm. The amplifier is stable into 2 ohm, while the minimum rated load is 4 ohm. Peak output voltage reaches 126 Vac, or plus or minus 179 V peak to peak, and peak output current is 120 A. Input sensitivity is 1.55 Vrms with an input impedance of 10 kohm, and a switch selects voltage gain of +38 dB or +26 dB. The frequency range runs from 1 Hz to 100 kHz, and full-power bandwidth covers 5 Hz to 25 kHz. THD+N is below -92 dB, equal to 0.0025%, output noise stays under 40 microvolts rms, and dynamic range exceeds 126 dB linear and 132 dB A-weighted. Damping factor is above 1000. It measures 440 x 298 x 545 mm and weighs about 75 kg.

Engineering and use context

In the output stage, 100 audio-grade power transistors share a peak current capacity of 720 A. The layout is fully symmetrical and bridged, with hand-matched devices kept in their linear region and no operational amplifiers in the signal path. A custom toroidal transformer with several output voltages feeds the power stages, which lets the Athene reach high output while keeping efficiency up. Bias comes from the DXDrive circuit in the custom DX901 hybrid chip - it reads the idling current directly rather than a temperature sensor and holds it at the set level whatever the heat, supply voltage or load. The input stage is a unity-gain buffer with relays choosing between the balanced and unbalanced inputs, followed by a limiter against overload. Protection watches temperature and handles soft start, mains fluctuations, DC at the output and RF interference. Chassis parts are CNC-machined from solid aluminium blocks. Idle consumption is 200 W, standby stays below 20 W, and current draw peaks under 10 A at 230 V, with the mains voltage set at the factory for 230 or 115 V. A transferable ten-year warranty applies.

Pairing

XLR balanced and RCA unbalanced inputs connect to either type of preamplifier, and 12 V trigger jacks in and out allow switching on together with other components. The low minimum rated load and the high current reserve point to loudspeakers with low nominal impedance and low efficiency.

Alternatives

The Analog Domain Apollo is the DX9 amplifier above the Athene by output, using the same M4 chassis at 4 kW into 8 ohm peak with a switchable +41 dB gain.