And while we’re at the interesting technical facts, here are few intersting common features of the Analog Domain upper echelon power amplifies.


The DX9 range is built around our proprietary DX901 hybrid chip, featuring the DXDrive™. It provides the driving signals and control functions in the power stages.

The DX901 is a custom IC, featuring premium discrete components on a high-performance ceramic substrate. Component location on the chip has been optimized through nine revisions to achieve a very low distortion figure, a wide dynamic range, and sustainable high performance at any output level. The low noise floor provides a near ‘black’ background for enhanced resolution at low levels.

Input stage

The input stage is an ultra-linear zero-feedback discrete complimentary unity-gain buffer. It provides standard input impedance and acts as a low impedance signal source for the power stages. Signal selection between the balanced XLR and the unbalanced RCA inputs is done with a dedicated relay featuring gold-plated silver contacts in a sealed case. The input stage includes a high-performance limiter. It will engage only in case of an overload, transparently limiting overdrive, consequent clipping and distortion.

Power amplification stage

The DX9 range amplifiers are fully symmetrical, bridged configurations. This setup provides a further reduction of distortion while maximizing dynamics. Each amplifier contains two identical power stages operating in inverse phase. The outputs are massively parallel, built with hand-matched ultra linear audio-grade power transistors. All devices are operated well within their linear region to ensure low distortion and high reliability. The term “difficult load” has no practical meaning.

Power supply

Massive, in-house designed, custom-built toroidal mains transformers are used in all our amplifiers. Filtering and energy storage is provided by long-life, high performance capacitors. The power block of the Apollo, Athene and Artemis supplies several voltages to the power stages to ensure both a high power output and a high efficiency factor. In conjunction with the DXDrive™, this setup has enabled us to build extremely powerful, yet relatively compact and energy efficient amplifiers with uncompromised performance and reliability. The Calysto is a classic design, powered by a fixed voltage for ultimate fidelity.


Our amps feature an extensive array of protection circuits to guarantee safe and reliable operation. Considerable effort has been made to ensure that these circuits engage only in exceptional circumstances and do not interfere under normal conditions.

Possible error states fall into two categories: self-resetting and non-resetting. An example of a self-resetting error state is overheating, which would cause either a temporary reduction in output power or complete muting, depending on actual heatsink temperature, to prevent irreversible damage. The amp will automatically resume normal operation when the temperature falls to a safe level. A non-resetting error will require manual intervention to draw attention to a serious error condition that should be rectified. An example is a short circuit at the output. Such events will force the amplifier into standby.

All amplifiers are protected against mains over/under-voltage, overheating, input signal overdrive, output short-circuit, DC voltage at output, excessive HF/RF. Current draw during initial power-up is limited by a dedicated ‘soft start’ circuit.