Controlling the Synthesizer parameters step by step.
So now we have all the building blocks (almost) for a basic sequencer, we need some means of getting it to control our synthesizer. This is where our next structure comes into play, the Step Prefab. The structure is shown below but there’s a couple of things I’ll elaborate on.
Gating the control voltages.
The input to the step prefab has a comparator. Why? Well we want to “gate” the control voltages we’re feeding to the synthesizer, otherwise they will all just add together at the output, not the idea of our sequencer.
The Comparator is set up so that when the Input A reaches 5 V the output will rise to 10V, anything below this and the output will be 0V. This is then fed to the Level Adj modules. When their Input 2 is at 0V there will be no voltage passed to the output, when the Input 2 switches to 10V the input signal will be passed through to the output. The Led 2 is added to show which of our 16 steps is active at any given time. Without the comparator the voltage reaching the Level Adj module will only be 5V, which will upset our tuning.
Setting the Pitch.
This is a slightly modified Detuner module the original is shown below, but (personally) having numbers for the notes doesn’t make it very “musician friendly”, plus we don’t really need the fine tune in this application.
As you can see here the fine tune control is removed, and we have the note names from the musical scale rather than numbers.
Important: Don’t edit the fixed vales for the notes, just the name properties for the switch and fixed value modules. Just delete the fine tune part of the prefab.
Control the Velocity.
Normally when we play a keyboard we get some variation in loudness, and often timbre dependent on how hard we play the keys. This is added in with a switch module and a set of Fixed Values (Volts). I used 0V, 2.5V, 5V, 7.5V and 10V to represent a useful set of velocity levels. No reason not to use a slider control for this… this is after all just to show how a sequencer can be assembled in SynthEdit.
Connecting the Steps up
I have only shown two steps to give you the idea (otherwise it’s just too complex with all 16 steps). The gate output connection is not used in this Sequencer.
Leave a Reply