The SEQ1 is the new pulsing heart of the system - an 8-stage CV and gate sequencer with a host of functionality. In combination with the various CLK modules, you can create a plethora of rich rhythmic control.
Have a look at the block diagram image to get an idea of the parts which go to making up the SEQ1.
The module begins with clock generation and processing. There is a simple internal clock generator with manual speed control and run control (allowing external gating) so that sequencing can be achieved simply 'in the box'. If preferred, an external clock signal can be used - indeed, external clocking gives wider possibilities than with the internal as the counting core is capable of being clocked up into high audio rates (try this in Random mode for digital noise generation). The selected clock source is passed both to an output socket (Clock
output) and to a pulse-stretching circuit which allows manual control of the gate length - this gate signal has a direct output (Gate
output)and is also used to control the gate sequence outputs.
The core is a controlled binary count which drives two 8-stage multiplexors - an analogue one for CV and a digital one for the two trigger/gate buses, individual step outputs and step LEDs. The direction of counting can be manually selected as up (right) or down (left) or an external gate signal can automate direction changes (low signal gives down count, high signal gives up count). There are also manual Step and Reset buttons, along with two OR'd Reset inputs.
The analogue multiplexor can be fed with either an internally generated voltage (0 to +10V range, manually controlled via the Range
dial) or an external signal can be applied to achieve sequenced level control (see the demo video for level sequencing of the Gate output). The selected stage passes both to the main CV
output and to a glide circuit which can be switched on manually or via the Gate A bus.
The digital multiplexor drives the two gate buses with each step having a switch to select Bus A, Bus B or Off (centre position). Each step also has an individual Step
output (top 8 red output sockets) which is high (+10V) when the corresponding stage is active. Each Gate output can be set to either Full
mode - in Full mode, the output is high for the whole active clock cycle, whereas in Gated mode the active step is AND'd with the clock's generated Gate signal so that the gate lengths can be adjusted. Note that in Full mode, if two adjacent steps are both high then the gate will stay high for both steps - ie the output is tied. In Gate mode you will tend to get individual gates per step (as long as the Gate Length is not set too long - in which case the steps would become tied).
On the rear of the module is a 6-pin expansion header which will be used to connect slave devices - for example, the planned SEQ1X expander which would offer extra CV and Gate outputs. The module is extremely shallow in depth, being built with a single PCB behind the front panel. Despite the diminutive size, no corners are cut with the circuitry - all gate inputs are conditioned through comparators so that any external signal can be used as a control, the analogue multiplexor can accept full range bipolar signals, and all outputs are fully buffered.
Added on Wednesday 21 September, 2011.