The Audio Precision System One Dual Domain test set: also DSP-equipped, includes all SYS-222 capability plus digital domain generation and analysis via digital inputs and outputs in the AES/EBU (balanced and unbalanced) and consumer (coaxial and optical) formats, plus parallel and general purpose serial I/O. With dual domain architecture, the analog hardware generator and analog hardware analyzer for analog domain devices are separate and independent from DSP modules which stimulate and analyze digital domain devices.