Clockwork Card 208–5

The Clockwork Card is a timing control hub designed to fit into the slot of the Stored Program Sound Source Model 208.

Inspired by Charles Cohen’s looping techniques, this card aims to provide an accessible way to control timing and create interesting rhythms. It offers multiple clocking options, 30 preset pattern banks, and the ability to shift and rotate rhythmic patterns across different destinations. The card also features two special modes (CLIX and Uncertainty Mode), and allows for customisation through its USB-C port.

Clocking Options

Select from three clock sources: the card’s internal clock generator, the 208’s pulser, or an external pulse (5 V or 10 V switchable). In external or pulser mode, the RATE knob serves as a clock divider from 1/1 to 1/16.

Dynamic Patterns

30 preset pattern banks, each containing four distinct rhythmic patterns assigned to the Sequencer, Envelope, Pulser, and Random destinations.

Destination Control

Each destination can be activated or deactivated with a switch. Rhythmic variations can be created by offsetting the Sequencer, Envelope, and Pulser patterns. Additionally, rotating patterns reassigns them to different destinations.


The card interfaces with the 208’s to card and from card banana jacks. The inverter to card jack serves as an external clock input, while the inverter from card output provides a switchable sum of the pulse outputs or the master clock.

The preamp’s to card banana jack allows for voltage-controlled pattern rotation or resetting to the first step.

Note: If you are using the 208c with MIDI, the MIDI velocity data will be presented at the from card jack, which can interfere with the clock output. You can disable sending the clock to this jack with a DIP switch under the front panel.


Clockwork Card 208-5


user Guide

Build Guide


Download to edit patterns or rewrite functions.
The firmware upload procedure is found in the user guide.

I assume no liability for personal injury or damage to equipment caused directly or indirectly by the use of these devices.