DoepferA-155 Analog/Trigger Sequencer

Doepfer A-155

The A-155 is a 8-step analog trigger sequencer that can produce analog voltages as well as trigger/gate signals. Think of it as a A-161 module on steroids. It features dedicated switches for Start, Stop, Step, and Reset functions, all of which are operable either by CV or manually via buttons. The sequencer's upper row is specifically geared towards pitch control, while the bottom section features external signal inputs for each step. Additionally, the module features three rows dedicated to triggers and one for gates. There is also a per-step toggle switch that allows users to select whether or not a trigger is active at a particular step. 

A-155 Features

• 8 potentiometers (knobs)
• Lower row: Scale (knob), voltage output range 0 ... ~ +6,5V
• Upper row: 1V/2V/4V (octave range switch for exact VCO control), voltage output ranges 0 ...1.0V / 0 ...2.0V / 0 ...4.0V
• Glide time (knob), same as portamento or slew limiter
• Glide Control (control input for switching glide on/off)
• S&H Control (control input for internal S&H, works like A-148)
• Pre Glide/S&H-Out (analog output before S&H and glide unit, especially required when external audio signals are used as inputs of the lower row)
• Post Glide/S&H-Out (analog output after S&H and glide unit)
• Lower row: external inputs for the 8 steps (switched jack sockets), control signals or audio signals may be used as inputs (allowed voltage range -5V...+12V), the knobs of the lower row are working in this case as attenuators
• 4 Trigger/Gate tracks with 2 rows of switches
• Toggle switches of 1-0-1 type (with middle position), which can be used to send a trigger/gate to the track above or below or to send no trigger/gate (middle position)
• 3 trigger rows (i.e. short pulse for each step set, pulse width corresponds to the pulse width of the clock/step input signal)
• 1 gate row (i.e. a high signal is applied during the length of the step set)