SynthMaker Manual Open SynthMaker (opens in a new tab)
Circuits

Parts you can turn

A setting line gives a circuit a knob that turns one of its parts, as a pot does. A wire can turn it too: an Envelope sweeping a filter's resistors on every note.

1A setting is a knob

Write a setting's name where a part's value goes and the knob turns that part, in its own unit, ohms or farads:

setting tone: 15k, from 1.5k to 150k
R2 a out tone
  • The knob turns on a log taper, like a pot. Without a range it turns a decade either side of its value.
  • A range written from the bigger value, from 220k to 2.2k, is a pot wired the other way round: turning the knob up takes the resistance down.
  • One setting can turn several resistors together (a dual pot), or several capacitors, but not both.
The Sallen-Key's card: knobs Input 0.50 V, Output 1.60 V, Cutoff 100 kΩ and Resonance 16.0 kΩ, and Open.
The Sallen-Key Bass's card: each setting a knob.

2Wires into settings

Every setting is also an input of the circuit's box, under its own name. Wire an Envelope, an LFO or any control signal into it and the knob turns from where it's set: +1 is half the knob's travel up, −1 half down, held inside its range. Several wires into one setting add up.

In Swept Sallen-Key an Envelope opens the cutoff on every note, then lets it fall back.

The Patch: two Oscillators into SallenKey, a circuit box with its schematic in small, and an Envelope wired into its cutoff input; then the VCA.
  1. The circuit.
  2. Its cutoff setting, as an input.
  3. The Envelope that turns it.

3The ring on a wired knob

A wired knob shows a thin ring outside its own, from where it's set to where the wires have it now, and a dot there. In SynthMaker, play a note and watch it move.

The Sallen-Key's card while a note plays: the Cutoff knob has a dot and a thin ring outside it, where the Envelope has it now.
A note held: the dot on Cutoff is the Envelope at work.

4How fast it runs

A circuit runs at the sample rate when it's linear, and at twice it with a diode or an op-amp's rails, to keep the clipping clean. An oversample 2x line (or 1x, 4x) sets it yourself.

Diode Pedal's parts list beside its schematic; under the schematic: 6 parts · runs at 2× the sample rate · knobs: input, output, tone.
Under the schematic: the rate it runs at, here twice the sample rate.

Try it

  1. Open Swept Sallen-Key and play low notes.
  2. Turn Cutoff up: the sweep starts higher.
  3. Turn Resonance up towards 19k: the filter rings at its cutoff.
Open the example sound: Swept Sallen-Key ↗ (opens in a new tab)

Remember