Retro Synth global and controller settings in Logic Pro for iPad
Retro Synth global controls are used to set the overall tuning, polyphony, and other aspects of your instrument.
The controller settings let you assign MIDI keyboard features to Retro Synth controls. You can use three MIDI controllers—velocity, modulation wheel, and aftertouch—to change Filter Cutoff, Wave Shape (Pulse Width), or LFO/Vibrato Rate controls. Multiple MIDI controllers can be assigned to the same control, so you could change filter cutoff with both velocity and aftertouch, for example. Alternatively, a single MIDI controller can be assigned to multiple Retro Synth parameters—with aftertouch affecting both filter cutoff and LFO speed, for example.
If you’re new to synthesizers and the concepts behind modulation controls, see Intro to synthesizers.

Global parameters
Tune knob and field: Tune Retro Synth in semitone steps.
Transpose pop-up menu: Choose a value to transpose Retro Synth ±2 octaves.
PB Range pop-up menu: Choose a value to set the maximum upward/downward pitch bend. Pitch bend modulation is typically performed with your MIDI keyboard pitch bend wheel or joystick.
Polyphony pop-up menu: Choose the maximum number of notes that can be played simultaneously (up to 16) or run as a monophonic synthesizer.
If you choose Legato and play in a legato style (strike a new key while holding another) the envelope generators are triggered only for the first note you play legato, and continue their curve until you release the last legato played key. This means that if you play legato, a portamento occurs (the portamento time is set with the Autobend / Glide Time control). If you release each key before pressing a new one, the envelope is not triggered by the new note, and there is no portamento.
If you choose Mono, staccato playing retriggers the envelope generators every time a new note is played.
Unison pop-up menu: Set the number of voices played in unison mode. Behavior in unison mode depends on the Polyphony parameter value. One of the strengths of polyphonic analog synthesizers is unison—or stacked voices—mode. Traditionally, in unison mode classic analog polysynths run monophonically, with all voices playing simultaneously when a single note is struck. Because the voices of an analog synthesizer are never perfectly in tune, this results in a rich, chorus-like effect with great sonic depth.
Polyphonic unison mode: When 2–16 voices are selected in the Polyphony pop-up menu, voices are stacked, but you can play polyphonically.
Monophonic unison mode: When Mono or Legato is chosen in the Polyphony pop-up menu, all voices are stacked, but you can only play monophonically or in a legato style.
Voice Detune knob and field: Tune Retro Synth in cents (1 cent = 1/100th semitone).
Stereo Spread knob and field: Set the amount of voice panning, relative to the center position. Voices are panned left or right in an alternating, symmetrical pattern.
Note: Detuning and panning works in Single and Double voice mode. In Double voice mode, detuning and panning affects the respective voice pairs.
Controller parameters
The modulation targets available in the pop-up menus listed below change when different synthesizer engines are active.

MW Mod Amnt knob and field: Set the maximum modulation depth for your keyboard mod wheel.
Mod Wheel To pop-up menu: Choose a modulation target for your keyboard mod wheel.
Vel Mod Amnt knob and field: Set the maximum modulation depth with keyboard velocity.
Velocity To pop-up menu: Choose a target for modulation with keyboard velocity.
Touch Mod Amnt knob and field: Set the maximum modulation depth with keyboard aftertouch.
Aftertouch To pop-up menu: Choose a target for modulation with keyboard aftertouch.
Ctrl X Mod Amnt knob and field: Set the maximum modulation depth with the MIDI controller chosen in the Ctrl X Source pop-up menu.
Ctrl X To pop-up menu: Choose a target for modulation with the MIDI controller chosen in the Ctrl X Source pop-up menu.
Ctrl X Source pop-up menu: Choose a MIDI continuous controller to use as a control source.
Note: This modulation source is ideal for use with MIDI CC#4 Foot Controller that’s often used in conjunction with aftertouch. It’s also useful for MPE devices that offer enhanced controller functions.
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