The Avalon Design AD 2022 dual mono Pure Class A microphone preamplifier represents the fourth generation of Avalon’s fully discrete Class A microphone preamplifier designs, building directly on the established architecture of the M2, M22 and M5 models. The Avalon Design AD 2022 retains the core design philosophy of high voltage, fully discrete Class A operation, while introducing refinements aimed at improved signal integrity, expanded functionality, and enhanced control over microphone interfacing.
The Avalon Design AD 2022 is configured as a dual mono unit, providing two completely independent signal paths. Each channel incorporates a high performance transformer balanced microphone input, designed with low ratio primary windings combined with a custom mu-metal core. This approach extends smooth frequency response while maintaining very low distortion characteristics. Signal routing is handled through sealed silver relays, ensuring minimal signal path degradation and consistent performance over time.
Input control on the Avalon Design AD 2022 includes a microphone selector, polarity reverse, +48V phantom power, a passive high pass filter, and a -20dB input attenuator. The high pass filter is continuously variable from 30Hz to 185Hz at 6dB per octave, allowing effective control of low frequency rumble, wind noise, and subsonic vibration without introducing significant phase shift. Input impedance selection is also provided, with transformer balanced load options enabling optimisation for different microphones and signal sources.
The amplifier topology of the Avalon Design AD 2022 is based on a symmetrical Pure Class A configuration using discrete, high voltage circuitry. Each channel employs two 100% discrete signal amplifiers, with the first stage operating in a cascaded FET configuration and the second stage utilising bipolar devices. This shared gain architecture improves transient response, extends bandwidth, and increases overall headroom capability. The design supports gain switching in 4dB increments, alongside a variable output trim control offering ±3dB adjustment.
Output stages in the Avalon Design AD 2022 are high current, DC coupled Class A discrete amplifiers, capable of delivering up to +36dB output level. The output is transformer balanced via XLR connectors, ensuring compatibility with professional studio systems and maintaining signal integrity across a wide range of loads. Metering is provided via large illuminated analogue VU meters, complemented by bi-colour LED peak indicators for accurate monitoring of signal levels at 0dB and +20dB.
Power for the Avalon Design AD 2022 is supplied via an external B2T toroidal power supply, supporting selectable input voltages from 100V to 240V at 50Hz or 60Hz. The use of an external supply isolates the audio circuitry from power related interference, while internal DC regulation ensures stable operation of the Class A stages. The chassis construction incorporates double plated circuit boards and silver wiring to further support low level signal transfer and overall reliability.
Features
- dual mono pure class a design
- transformer balanced microphone and instrument inputs
- selectable input impedance matching
- gain switching in 4dB steps with output trim control
- variable high pass filter from 30Hz to 185Hz
- sealed silver relay signal routing
- analogue VU metering with LED peak indicators
- external toroidal power supply with internal regulation