10.6

38Logic Pro Instruments
• Partial knob: Define the pattern of (groups of) partials affected. Set to 2 to
limit the detuning affect to only partials 2, 4, 6, 8, and so on; set to 3 to apply
detuning to only partials 3, 6, 9, 12, and so on. Higher values affect fewer
partials, which in turn changes the impact of the Amount knob, making it more
subtle.
• Tuned knob: Set the range for the Amount knob. This knob behaves like a switch.
On: At the zero position, the selected partial is tuned down to the pitch of the
second partial below. When the Amount knob is at 100%, the selected partial is
unaffected.
Off: At the zero position, the selected partial is tuned down to the pitch of the
second partial below. When the Amount knob is at 100%, the selected partial is
tuned up to the pitch of the next partial above.
• Stretch: Allows the tuning of partials to be stretched upward, sharpening upper
partials while retaining the original fundamental tone pitch. This stretching of the
harmonic series is typical of instruments that use vibrating strings or tines.
• Amount knob: Stretch the tuning of all partials equally. Higher values increase
the intervals between partials and shift higher partials upward. Lower values
decrease the intervals between partials and shift higher partials downward. This
is a quick way to tune upper partials without the need to manually edit partial
pitch values in the additive editor. See Logic Pro Alchemy additive edit window
overview.
• String knob: Stretch the tuning of higher partials more intensely than lower
partials. Small increases can result in a subtle sweetening of the sound without
altering its basic character. Larger increases can add an inharmonic, metallic, or
bell-like quality to upper partials. Modulate this parameter with an envelope to
add a plucked string type articulation to the start of a note.
• Shift: An unusual frequency shifter type effect that moves all partials up or down
by the same amount in hertz, thereby breaking the harmonic relationships between
them. In a sound with a fundamental frequency of 220 Hz and a second harmonic an
octave higher at 440 Hz, an upward frequency shift of 100 Hz results in partials at
320 Hz and 540 Hz, with the second partial no longer an octave higher than the first.
This effect type can radically alter the harmonic structure, leading to inharmonicities
and atonalities, in addition to a perceived change of the fundamental pitch.
• Pitch knob: Set the amount of shift for the first harmonic. All subsequent partials
are shifted by the same amount in hertz rather than in semitones because this
would result in a simple pitch change. Defining the frequency shift in this way
retains a consistent timbre as you play up and down the keyboard.
• Freq knob: Define a static shift in hertz. Because the shift does not track the
keyboard, the timbre of the resulting sound changes from note to note. When
combined with another harmonic sound (in the VA section, for example), small
shifts can create beating, chorus-type effects between the source elements.
• Magnet: Allows you to shift the tunings of all partials toward a specified target pitch.
This can lead to unusual effects and can result in dramatic transformations of the
sound.