JS Synths Index

Trigger and Analog Sequencer

A 4 channel trigger and 2 channel annalog sequencer, each with 8 steps.


The TrigSeq-Module is the one with copper face.

The right side : 2 x 16 switches, on the top LED's as display.

Each 16 - switch - row contains 2 independent 8-step trigger sequencers,


Thus, the left and the right part (each 8 switches) both are working with

the same frequency and phase.

On the left side the 2 analog step sequencers (CLOCK, RESET, OUT).

The output CV can be adjusted by a Pot (top of the LEDS of the TrigSeq).

Here you can see the version of my 3 channel 16 step trigger sequencer, showing the schematic and the backsite of the front panel with the 3 devices.

16 Step Trigger Sequencer


Voltage controlled gate length

This is the schematic of a voltage controlled trigger length, which could be very useful for the trigger sequencer (in combination with an analog sequencer or an ADSR, for example) to generate different note length (thanks to Marco Manieri for this idea).


In the schematic, you will see numbers in circles from 1 to 3 : these refers to the osciloscope pictures below :

(1) The first step is shown below : the clock input signal is converted into a short pulse.


(2) This pulse is then used for generating an AR-envelope. Attack is set to 0, Release can be modified and has to be adjusted depending on the trigger length time range.


(3) The last step is simple : a comparator gives +12v or -12V, depending on a voltage level given by "length control", and working as a threshhold level for the comparator. -12V is then transformed inot 0 V and +12V to whatever you want as trigger voltage.