10.6

91Logic Pro Instruments
Note: Distortion effects created in the source and main filter sections are polyphonic, with
each voice distorted independently. This avoids unpleasant intermodulation effects when
you play chords. In contrast, the Distortion module in the effects section at the end of the
signal path processes a mix of all voices.
The filter controls work as follows when the filter type is set to a distortion effect:
• Amount: Controls the intensity of the distortion effect.
• Mix: Controls the mix between clean and distorted signals. A value of 0% results in the
clean signal only. A 50% value results in an equal mix of clean and distorted signal. A
100% value results in the distorted signal only.
• PreGain/Freq: Boosts the input gain. Sets the frequency for the Downsample distortion
type.
Alchemy filter types: compressor and FM
These tools provide creative options at the filter stage of the signal path. Unlike dedicated
FM synths, Alchemy does not have preconfigured algorithms or a mod matrix setup
specifically for FM. It does, however, offer the option to run a huge number of FM filters in
various series and parallel configurations. FM in Alchemy also has a different character to
classic FM synths. FM in Alchemy is more like working with FM on analog synths where you
are modulating oscillator frequency rather than phase. As a result, Alchemy’s FM is great
for adding different kinds of effects to your sound, as well as “organic” distorted textures.
The filter controls work as follows when the filter type is set to Compressor:
• Thresh: Set the threshold level—signals above this threshold value are reduced in level.
• Ratio: Set the compression ratio—the ratio of signal reduction when the threshold is
exceeded.
• Gain: Set the amount of gain applied to the compressed signal.
The filter controls work as follows when the filter type is set to FM:
• Freq: Set the carrier oscillator frequency.
Tip: For classic FM sounds, double-click the Freq knob to set it to the center
position, then Control-click the knob and choose Add Modulation > NoteProperty >
KeyFollow from the shortcut menu.
• Mod: Set the degree to which the modulator (source audio) can modulate the frequency
of the carrier.
• F-Back: Set the amount that the output of the carrier is fed back into itself.