The A-155 acts as the physical center of an analog system, focusing on direct switch and knob interaction rather than digital navigation. It features two rows of eight potentiometers that output independent control voltages. The upper row is calibrated for pitch control with a selectable octave range switch, while the lower row offers a wider voltage swing or functions as a series of eight attenuators for external signals. This dual-nature design allows the sequencer to act as both a melodic generator and a complex rhythmic signal processor within the same patch.

In a live workflow, the A-155 encourages real-time interaction through its dedicated trigger and gate switches. Each of the eight steps uses a three-position toggle, allowing you to send a pulse to the upper track, the lower track, or neither. Because the module includes built-in Glide and Sample and Hold circuits, you can smooth out pitch transitions or create stepped modulation directly from the front panel. It is designed to be the foundation of a sequencing setup, and while it operates perfectly as a standalone clock-driven unit, it remains open to expansion for more complex addressing or quantization.