Manufacturer's Description
AD255 is the latest addition to the Audio Developments Ltd. range of portable mixers, having comprehensive facilities set out in an ergonomically friendly design and all contained within a robust and rugged aluminum case with a relatively small footprint.

The features and specifications are based on the well-established AD245 Pico Mixer. Two auxiliary sends and channel direct outputs are the main additional features. As with the other models within the range, professional components are used throughout, including Penny and Giles 100mm long-stroke, conductive plastics faders.

Location sound professionals now require multi-track record facilities. The channel direct outputs provide the necessary features without compromising the simplicity of operation and reliability of its counterpart, the AD245.

• Low noise microphone amplifier developed for AD140 series of mixers. Power is provided for 48V Phantom and 12V Tonader microphones
• A simple but effective three band equalizer, proved and approved under field conditions, in use throughout the AD140 series of mixers.
• Inputs are transformer balanced and protected against radio-frequency interference. A high-pass filter protects against low-frequency saturation.
• The main stereo output is transformer balanced and has separate left and right faders.
• Two auxiliary outputs are transformer balanced and have separate master rotary controls. Auxiliary 1 & 2 are routed from each input using a 3 position switch (off, pre, and post fader). Auxiliary 2 has a rotary level controller.
• Limiters, which may be linked for stereo operation, are incorporated in the main output. Limiting is indicated by a pair of LEDs.
• Input direct outputs are unbalanced and driven from a very low impedance source with high drive capability.
• Two LCD meters display - either PPM or VU - monitor the main output, auxiliary output and PFL of each input. Useful for monitoring levels at a direct output. Battery level and monitor status (Direct or Return) are also indicated. Meters can be illuminated.
• The frequency of the internal oscillator can be selected between 1KHz and 10 KHz, its output replacing the signal on the main output.
• Via an internal microphone, the mixer operator is able to communicate with the main output (SLATE) and with an outstation (EXT). The outstation normally receives a mono of the mixer's main output.
• The headphone monitor may be selected between main output, auxiliary outputs and return All have PFL override. Monitor selectors allow left, right, left + right, auxiliary 1, auxiliary 2, and auxiliary 1 + 2 to be routed to the headphone socket. An M-S matrix amplifier may be inserted in order to decode main or auxiliary outputs in the MS domain.
• An electronically balanced stereo tape return appears on a pair of stereo jack sockets. An input calibration potentiometer is adjacent to the jack sockets on the connector panel.
• All input and output connectors are presented on one surface of the case and in line with their corresponding modules.
• The mixer receives power from 8 X C cells fitted internally or from an external 12V-15V source.

Specifications:

AD255 Manual (pdf)