Modulation

• Working with modulators
• Types of modulator
• Modulation rack controls
• Modulator knobs are different
• Finding a modulator’s targets
• A very simple modulation example
• Modulating LFO Rate
• Modulating modulation depth

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Alchemy features a unique ‘modular’ modulation system which combines ease of use with almost limitless flexibility. It’s a bit different from an ordinary synthesizer’s modulation system, but don’t worry: you can learn the basics in no time.

Working with modulators

Nearly every knob on the Alchemy interface is a mod target, representing a parameter that can be modulated by as many as five modulators. Whan a knob has one or more modulations assigned to it, a green mod arc is illuminated alongside the knob’s blue value arc. This confirms that the knob is a mod target, and also indicates the effective range of the modulation.

To view or edit the modulations assigned to a parameter, normally you just have to click the parameter’s knob. The parameter name is shown in the Target field at the top left of the Mod section; directly below it, you’ll find a mod rack with five slots. Click a different knob and the mod rack will be updated accordingly.

  • To select, create or change a modulator, click a slot in the mod rack and choose from the pop-up menu that appears.
  • To undo a modulation assignment, choose ‘None’ from the pop-up menu. The modulator will no longer affect the currently selected target (although it will still be available for assignment to other parameters).
  • To delete a modulator entirely (so that it no longer affects any parameters), choose ‘Del’ from the appropriate sub-menu (e.g. to delete LFO 2, click a slot and in the pop-up menu choose ‘LFO’ > ‘Del LFO 2’).

You can also work with modulators by right-clicking a target knob and choosing a command from the context menu that appears.

  • ‘Add modulation’ lets you assign a new modulator by selecting it from the appropriate sub-menu. The new modulation will appear in the first empty slot of the mod rack.
  • ‘Clear modulation’ removes all modulations from the knob, leaving the mod rack empty.
  • ‘Copy modulation’ places information on the clipboard about all the currently assigned modulators.
  • ‘Paste modulation’ applies all the modulator information from the clipboard. Using the ‘Copy’ and ‘Paste’ commands, you can quickly assign the same modulations to multiple targets.

Note that the most recently clicked knob is highlighted with an illuminated spot in the center. This makes it easy to see at a glance which knob represents the current target. If you switch between sub-pages in the interface (e.g. from the Source A to the Source B sub-page), the highlight will shift to the corresponding knob on the new page, so you can quickly set up modulations to a recurring parameter such as Fine Tune on multiple sub-pages.

Types of modulator

The available modulator types are as follows:

Each one is described on its own page.

Modulation rack controls

Each slot in the mod rack has its own ON button (for toggling the loaded modulator on or off) and its own Depth control (adjustable from -100% to 100%). Double-clicking a Depth control resets it to zero.

Each slot also has a button marked E (for Edit). Clicking it causes the selected modulator’s control panel to be displayed in the right-hand half of the MOD section. Click a different modulator’s Edit button and the display updates accordingly.

Between the Edit button and Depth control, each slot also has a pop-up menu where you can assign, create or delete a ModMap.

The ModMap module is described on its own page.

Finally, a Smooth knob is available at the top of each mod rack. At the default value of zero, Smooth has no effect. At higher values, Smooth causes the target to respond more gradually to modulation. If you find that rapid Filter or Amp modulation causes unwanted clicks in your sound, one solution is add a small amount of smoothing via this knob. Larger values of smoothing also produce interesting effects.

Modulator knobs are different

Normally, two things happen as soon as you click a knob. First, the mod rack associated with the clicked knob is displayed at the left of the Mod section. And second, if a modulator has already been assigned to the first slot in the newly displayed rack, then its control panel appears in the right-hand half of the MOD section.

But in two cases, Alchemy prevents these things from happening. If the knob you click is located on a modulator control panel (for instance, if you’ve clicked LFO Rate or AHDSR Attack Time), Alchemy assumes you want to adjust the modulation of the current target instead of switching to a new target. Similarly, if you click on a modulation Depth knob in the mod rack, Alchemy assumes you want adjust the depth setting, so it keeps the current rack (and thus the knob you’ve just clicked) in view.

You can still view and edit modulation assignments in these cases. If a knob is located on a modulator control panel or in the mod rack, just right-click it to access a contextual menu with all the usual commands plus a new one: ‘Edit Modulation’ brings the knob’s mod rack into view immediately. For more details, see the examples below.

Note that a few knobs cannot be modulated.

  • The ‘Smooth’ knob at the top of each mod rack is not a mod target.
  • You can modulate a mod depth. But you can’t modulate the depth of modulation of a mod depth — which is just fine, because it would take more sentences like this one to explain it if you could!
  • Knobs in the Perform section are not mod targets; they are intended as sources, rather than targets, of modulation.
  • If a parameter is set via a menu selection rather than a knob (e.g. Loop mode, Filter type), then you can’t modulate it.

Apart from these few exceptions, if it’s a knob, you can modulate it in Alchemy. This includes additive/spectral/granular play position, AHDSR times and levels, and numerous Effects parameters. Try them and see!

Finding a modulator’s targets

The mod rack shows you at a glance all the modulators that are applied to a particular target. But consider the reverse situation: how do you find all the targets of a particular modulator? This information is available via the Target button, which is located at the top right of the Mod section.

Clicking the Target button opens a pop-up menu listing all the modulators currently in use, and all the targets to which each modulator is assigned. For example, if you initialize Alchemy (by clicking the FILE button and choosing ‘Clear’ from the pop-up menu), then you can browse the Target menu to see quickly that:

  • AHDSR 1 modulates Master Amp
  • Velocity (a Note Property) modulates Master Amp
  • No other modulations have been assigned

A very simple modulation example

1. In Alchemy’s Title bar, click FILE and choose ‘Clear’ to initialise the preset. Play a note and you’ll hear the familiar default sawtooth wave.

2. In the Source section, click the Amp knob for Source A. In the Mod section, the Target field will change to read ‘Amp A’.

3. Click in the top slot of the rack and from the pop-up menu choose ‘LFO’ and then ‘LFO 1′. Click the LFO button to display the LFO controls in the field to the right.

Notice that Source A’s Amp knob is now surrounded by an illuminated green band. Read ‘Working with modulators’ (above) to find out why!

4. Hold a note and you’ll hear a ‘tremolo’ effect, as Source A’s amplitude is modulated by LFO 1. Change the LFO’s Rate setting to adjust the speed of the effect.

5. Try adding another modulator to the rack (in the slot beneath where LFO 1 is loaded) and see what effect that has.

Up to five different modulators of any type can be assigned to each control in a preset.

Modulating LFO Rate

In the preceding example, we created a ‘tremolo’ effect by modulating Source A’s Amp knob with LFO 1. Next, we’ll modulate the Rate of this LFO with KeyFollow, so that the tremolo effect is faster for higher notes.

Note: you can adapt this example to work with other modulator parameters, such AHDSR Attack time.

1. Right-click LFO 1’s Rate knob and choose ‘Add Modulation’ > ‘Note Property’ > ‘KeyFollow’.

2. ‘LfoRate’ now appears in the Target field, and KeyFollow is listed in the first slot of the mod rack.

3. Play a variety of higher and lower notes to hear the effect of KeyFollow on the LFO Rate. If this effect is too extreme, you can reduce the Depth setting in the first slot of the mod rack.

4. You can read more about the KeyFollow modulator on the Note Property page.

Modulating modulation depth

Each modulator has its own Depth control, and each Depth control can itself be assigned a modulator.

Note: a modulator can even be set to modulate its own Depth!

1. Right-click a Depth control in the modulation rack.

2. From the pop-up menu that appears choose ‘Edit Modulation’.

3. The Depth control’s name will appear in the Target field, e.g. ‘Mr1Depth’ (indicating that the target is Mod rack, slot 1 Depth).

4. Add one or more modulators to the rack in the usual way.

5. Note that the Modwheel is not available directly as a modulator. Instead, the Modwheel is always linked with one of the Perform controls. If you are starting from an initialised preset, you can assign the Modwheel to control a mod Depth by choosing ‘Perform’ > ‘Control7’ as a modulator.