Manufacturer Description:
Overview

Vintage edition with black faceplate and custom knobs.

The A-154 is an additional module for Doepfer's sequencer A-155 expanding it by a number of very interesting functions like CV selectable new modes of operation, e.g. one-shot and voltage controlled step addressing. A VC clock generator with variable pulse width is included as well. It's even possible to connect and control two A-155s either in parallel or in series for creating a 16-step sequencer.

Details

All parameters of the A-154 equipped with potentiometers also feature CV inputs with attenuators.

MODE sets the operation mode of the sequencer: forward, backward, pendulum, rando or with step addressing (CV Ctr.). All this either as a repetitive sequence or as a one shot. In the CV Ctr. mode it's possible to set the first and least step of the sequence with the FIRST and LAST potentiometers and thus to address the steps individually. Voltage control makes it possible, for instance to create a short 3-step sequence and move it within the eight possible steps. Or you shorten temporarily a long sequencer to add a variation.

A clock generator is integrated. Its frequency is determined with CLOCK and the pulse width with PW. The pulse width has an effect on the length of the triggers and gates which are produced by the A-155. The generated clock is available at two outputs for synchronising other modules.

The clock generator is normalized to the Ext.Clock input of the transport controller section. This offers buttons and switching inputs for start, stop and reset as well as the already mentioned clock input.

Per se it's identical to the A-155's transport section but in this case the A-154's section can control two A-155s at the same time! These can run either in parallel as two 8-step sequencers or in series as one 16-step sequencer (a A-150 switch module is required to be able to switch between the CV rows.) which is controlled by the toggle switch "Steps 8 16" or a switching signal at the "1-8 | 9-16" inupt.

If you desire to use the internal transport section(s) ot the A-155(s) again you can easily re-activate it/them by using the toggle switch or a signal in the section "A-154 Master". connectors

CV inputs: Mode, First Step, Last Step, Clock speed, Clock PW
transport: start input, stop input, reset input, clock input, 2x clock output
8-/16-step length input, external master input
dimensions

3U Eurorack expander module, 22HP wide, 80mm deep
60mA current draw