iOS Manual

1. About VMEGAfm for iPad

VMEGAfm for iPad contains two closely related instruments in one installation:

Both interface modes use the same four-operator, sine-only FM instrument. They share factory sounds, user presets, global preferences, and synthesis behavior.

VMEGAfm also carries the distinctive output character of the actual MEGAfm Mark I hardware: a carefully modeled analog stage adds subtle compression, saturation, and non-linear response after the digital FM engine. This is part of the sound in both the full-screen app and the hosted AUv3 instrument.

2. System Requirements

Older supported iPads can run VMEGAfm, but a busy host session may need a larger audio buffer or fewer simultaneous instruments and effects.

3. Installation and Opening the AUv3

Install the app

1. Install VMEGAfm from its authorized distribution source.
2. Launch the VMEGAfm app once so iPadOS can make the AUv3 instrument available to compatible music apps.
3. Keep the iPad in landscape orientation for the full-screen app.

GarageBand for iPad

1. Open or create a GarageBand song.
2. In the Sound browser, swipe to External.
3. Tap Audio Unit Extensions.
4. Select VMEGAfm. GarageBand creates an instrument track and provides its own keyboard, transport, recording, and track controls around the compact VMEGAfm editor.

Apple documents this workflow in Use other music apps with GarageBand for iPad. GarageBand wording and button placement may change between releases.

Other AUv3 hosts

Add VMEGAfm as an instrument or music device, not as an effect. Route MIDI to it and connect its stereo output to the host mixer. Hosts differ in how they expose plug-in windows, MIDI clock, MPE, preset snapshots, and file access.

4. Full-Screen App vs Hosted AUv3

5. Quick Start

Full-screen app

1. Launch VMEGAfm in landscape.
2. Select a factory sound from the top-left factory browser. A fresh installation starts on 07 Time To Rain.
3. Play the onscreen keyboard.
4. Move operator Total Level and Multiply faders, then try a different algorithm.
5. Press write and name the patch when you want to keep it.

GarageBand or another host

1. Add VMEGAfm as an AUv3 instrument and open its custom view.
2. Choose a factory preset in VMEGAfm's own top bar.
3. Use the voice tab for basic performance and reverb controls.
4. Use op1-2 and op3-4 to shape the sound.
5. Use lfo for movement, and the far-right Link 1/2/3 tabs to connect the last-touched control.
6. Record MIDI in the host. Save the host song for complete instance recall; use VMEGAfm Write for a portable user preset.

6. Touch Interaction

VMEGAfm uses enlarged invisible hit areas around compact knobs and faders, especially in the hosted interface. The visible controls do not overlap, while their touch zones fill as much free space as possible.

Knob

Touch and drag vertically. Hosted controls remain smooth and responsive even during vigorous movement.

Fader

Touch near the fader and drag vertically. The hosted fader hit area is wider than the drawn track.

Algorithm

Tap an algorithm LED/drawing directly, or drag the Algorithm knob.

Voicing

On the Voice tab, tap the text Poly12, Wide6, or Unison. The labels are invisible-button hitboxes; the LED shows the selection.

Tune center

Double-tap the Global Tune or Preset Tune slider to return to zero.

Preset browser

Scroll by dragging. A preset loads only when touch-down and touch-up complete without becoming a scroll gesture.

Ghost faders and knobs show the effective LFO-modulated position while the normal control remains at its stored base value. A blue halo appears around the current CC Learn target only while CC Learn is active.

7. Presets and Shared User Banks

Factory and user browsers

The Factory browser contains built-in, read-only sounds. The User browser contains sounds you write or import. Both browsers are drawn inside VMEGAfm, so they remain visible and touch-safe even when GarageBand does not display native plug-in pop-up menus correctly.

The full-screen app opens with factory preset 07 Time To Rain on each launch. A new AUv3 instance also uses it when there is no valid host state. The physical-style Reset button loads 01 Clean(ish) Sine. A host song restores the state saved for its AUv3 instance.

Top-bar actions

Write

Names and stores the current sound in the shared user bank. A matching existing name is updated.

Delete

Deletes the currently selected user preset after confirmation. Factory entries cannot be deleted.

Import

Uses the iPad document picker to read VMEGAfm XML or a compatible MEGAfm preset-bank SYX file.

Export

Uses the document picker/share flow to save the complete user bank as XML.

Add or replace

Import asks whether to add the chosen bank to My Presets or replace the current bank. The first imported sound loads immediately and is highlighted. Duplicate names are made unique. Export before Replace if the current user bank matters.

Sharing between FS and AUv3

The full-screen app and AUv3 instrument share the same VMEGAfm user-preset library. A preset written in the app becomes available in GarageBand, and a preset written in GarageBand becomes available in the app. If a browser was already open, close and reopen it or reopen the plug-in to refresh the list.

The host's own Presets or Save Sound feature stores a host-specific snapshot. VMEGAfm Write stores a VMEGAfm user preset that can be exported and used in other hosts. Both are useful, but they are not the same library.

8. Full-Screen Interface

The FS panel closely matches the desktop standalone application. Its header and major sections are always in fixed positions so the panel reads like an instrument rather than a collection of pages.

Header

Factory / User

Open the built-in preset browsers.

Write / Delete

Create or remove user presets.

Import / Export

Exchange user banks through the iPad document picker.

Settings

Opens the global settings overlay.

Links

Scrolls the complete panel upward to reveal the full modulation matrix, then returns to the main panel when closed.

CC Learn

Shows controller assignments over learnable knobs/faders and accepts an incoming standard MIDI CC for the selected target.

Hold

Applies sustain to the onscreen keyboard.

Main panel sections

• Global: algorithm knob/drawings, feedback, display, preset navigation/reset, and reverb flap.
• Operators 1-4: Total Level, Multiply, Attack, Decay, Sustain, and Release faders.
• LFO 1-3: Rate, Depth, select/link buttons, waveform, Retrig, and Loop.
• Arp: Mode, Rate, Range, and Rec.
• Vibrato: Rate and Depth.
• Voicing: Poly12, Wide6, Unison, Fat, Glide, and Volume.
• Keyboard: octave movement, Hold, multitouch notes, and optional Slide.

Display behavior

• The active factory or user preset index returns to the display after temporary value feedback.
• Algorithm, feedback, ratios, envelope values, rate choices, and mode changes briefly use the display.
• VE, AT, and SL identify velocity, aftertouch, and Slide overrides during deliberate edits, not during a preset load.
• The selected LFO waveform LED remains on and glows brighter with LFO intensity.
• Moving an operator fader temporarily changes the LFO LED cluster into the operator envelope-loop display.

9. Compact Hosted AUv3 Interface

The hosted interface is intentionally rearranged for the reduced height available above GarageBand's keyboard and transport. It sounds and behaves like FS, but exposes related controls one tab at a time.

Hosted top bar

From left to right, the bar contains Factory, User, Write, Delete, Import, Export, Voice, Op1-2, Op3-4, LFO, Settings, and three numbered Link tabs. The Link 1/2/3 tabs refer to the last knob or fader you touched:

• An inactive link tab has a dark body with a white outline, white chain icon, and white number.
• An active assignment fills warm white; its chain icon and number become dark so they remain legible.
• The link tabs are static status controls. They do not pulse with the LFO waveform.
• Tap a link tab to toggle the current control's assignment to that LFO. A disabled tab means the requested self-link is not legal.

Voice tab

Op1-2 and Op3-4 tabs

Each page shows two operators and uses the vertical space for 16 large fader lanes: eight per operator.

Above the faders, both operator tabs show Algorithm, the eight algorithm diagrams/LEDs, Feedback, and a dedicated Loop button/LED for each visible operator. Tap an algorithm LED/drawing directly. Loop buttons are momentary; their separate LED shows state and does not latch the button artwork.

LFO tab

The top row contains six shape/action buttons and LEDs: Square, Triangle, Saw, Noise, Retrig, and Loop. Below are three framed Rate/Depth pairs. An activity LED between each pair shows that LFO's instantaneous value. The Links shortcut opens the routing matrix without consuming top-bar width.

Links page

The Links page has four subtabs in this order: voice, op1-2, op3-4, and lfo. Every parameter row has cells 1, 2, and 3 for the three LFOs. Off cells are neutral gray; active cells are warm white. An LFO's own Rate and Depth cells are disabled for that LFO.

• Voice: Algorithm, Feedback, Fat, Arp Rate, Arp Range, Reverb Mix, Reverb Size.
• Op1-2: Detune, Multiply, Level, Attack, Decay, Sustain, Sus Rate, Release for operators 1 and 2.
• Op3-4: The same rows for operators 3 and 4.
• LFO: LFO 1-3 Rate/Depth plus Vibrato Rate/Depth.

10. How Four-Operator FM Works

Each of the four operators is a sine oscillator with its own ratio, output level, and envelope. An audible operator is a carrier. An operator that changes another operator's frequency is a modulator. The algorithm selects the routing; operator 1 owns feedback.

Increasing a carrier level raises its contribution to loudness. Increasing a modulator level raises modulation index and therefore spectral brightness or complexity. In a chain, a fast-decaying modulator over a slower carrier is a reliable way to create an acoustic-style attack.

Multiply and Feedback

Multiply offers 0.5 and integer ratios 1-15. Harmonic integer relationships produce stable pitched sounds; high or widely separated ratios produce tines, bells, metal, and effects. The curated VMEGAfm patch convention often uses displayed Multiply 4 for the principal carrier and chooses other ratios relative to it.

Feedback sends operator 1 into itself. Small amounts add harmonics; high amounts can become raspy or noisy, particularly when operator 1 is deep in a modulation chain. Feedback is especially effective for percussion and special effects.

11. Operators, Custom ADSR, and Envelope Loops

Core operator controls

Approximate envelope timing

For a piano, bell, mallet, or pluck, set Sustain to zero and use Decay for the natural tail. For an organ, pad, brass, or drone, use a nonzero Sustain. A modulator can have a shorter decay than the carrier to create a bright transient that settles.

Operator looping in FS

1. Move any fader belonging to an operator.
2. For about two seconds, the LFO shape/retrig/loop cluster displays that operator's envelope-loop state.
3. If the operator loop is enabled, the Loop LED pulses at 3 Hz.
4. Tap Loop during this period to toggle the focused operator.

Operator looping in hosted mode

Op1-2 provides Loop1 and Loop2; Op3-4 provides Loop3 and Loop4. Tap once to toggle. The button remains visually momentary and the separate LED carries the persistent state. A looping operator cycles Attack, Decay, Sustain, and Release while the key remains held.

12. Voice and Performance

MPE uses the 12 channels as independent member lanes and temporarily bypasses normal Poly12/Wide6/Unison allocation. The previous normal mode returns when MPE is disabled.

13. LFOs, Quick Links, and the Link Matrix

There are three independent modulation buses. Each can use Square, Triangle, Saw, or Noise; can retrigger per note; can run once or loop; and can connect to many parameters at the same time.

LFO controls

Link rules

• Move a knob/fader first, then use Link 1/2/3 to connect it in hosted mode.
• In FS, move a target and use the LFO 1/2/3 select/link buttons, or edit the complete Links page.
• A parameter can receive more than one LFO. Their signed changes add together.
• The result clips at the parameter minimum/maximum and never wraps around.
• An LFO cannot modulate its own Rate or Depth. The relevant cell/tab is disabled.
• Reverb Mix and Size use their full meaningful ranges when modulated, just like other knobs.

Visual feedback

FS brightens the selected waveform LED with the LFO value. The hosted LFO page instead has one activity LED between each Rate/Depth pair. Hosted Link 1/2/3 tabs do not visualize waveform amplitude; they only report and edit whether the current target is linked.

On either main interface, a translucent ghost or halo follows the modulated effective knob/fader position. The normal control remains at the base value so you can see the center of modulation.

14. Arpeggiator and Step Sequencer

The arp captures held notes when Mode is not Off and Rate is above zero. Range spans one to four octaves. In FS, the Mode button cycles modes; in hosted mode, tap the on-panel mode field to open a direct list.

Record a sequence

1. Tap rec. The Rec LED indicates recording and the old sequence is cleared.
2. Play notes in the required order. The first note becomes the reference; later notes are stored as semitone offsets so the pattern transposes.
3. In FS, use preset-up to insert a rest and preset-down to remove the last step.
4. Record up to 16 steps.
5. Tap Rec again to finish, then choose Seq or Seq Hold.

Sequence recording is disabled under MPE. Arp Sync follows host/MIDI clock. Retrig-enabled LFOs restart for each generated arp note, which is useful for repeatable rhythmic timbre envelopes.

15. Reverb and Output

Mix

Plate reverb dry/wet amount from 0% to 100%.

Size

Plate size/decay time from approximately 0.2 to 10.0 seconds.

No Reverb

Global bypass in Settings. It ramps the wet path cleanly, keeps the FS flap shut, and hides the hosted Mix/Size frame without erasing its stored values.

Vol

Patch output level and drive into the character stage.

In FS, tap the REVERB flap to reveal Mix and Size. In hosted mode, they are in the Voice tab. Reverb parameters are saved with each sound; No Reverb is a global preference. Startup and bypass transitions are ramped to prevent loud pops and unwanted reverb tails.

Automatic level control keeps the output strong and helps prevent unwanted digital clipping. There are no additional controls to set.

16. Full-Screen Keyboard

The built-in keyboard is available only in FS. Settings cycles it through 3 octaves, 2 octaves, and Off. Turning it off gives the panel more vertical room. The octave position is remembered.

Arrow buttons

Shift the visible range one octave at a time.

Two-finger horizontal drag

Scrolls the keyboard without playing notes. Existing notes are released when two-finger scrolling starts.

Hold

Applies sustain-pedal behavior to touchscreen notes.

Slide

With Slide > LFO3 enabled, vertical key position sends per-note aftertouch: top is 127, bottom is 0.

Range

MIDI notes 12-96, displayed as C0-C7. The visible span is 24 or 36 semitones.

Slide is polyphonic for linked operator parameters: moving one finger vertically affects that finger's voice. Parameters that are global by nature, such as Algorithm or Reverb, remain global even when driven from the latest expression lane.

17. Settings Reference

FS displays Settings as a three-column overlay. Hosted mode splits the same material into control, tuning, lfo sync, and lfo map tabs so every control fits above the host keyboard.

Control

Tuning

Closing Settings automatically turns off the 440 Hz tone and releases Play A4. There is no Audio/MIDI Settings button on iOS; the current host and iPadOS control the audio route.

LFO sync

LFO map

Velocity, Mod, Aftertouch, and Slide mappings override the normal waveform of their assigned bus rather than adding another LFO. Depth still determines the maximum amount and the Link matrix still determines destinations.

18. Shake to Shuffle

Shake to Shuffle creates small variations rather than replacing a patch with random values. Each detected gesture moves any affected parameter by no more than approximately 5% of that parameter's full range and clips safely at its limits.

Detection

• A gentle shake requires a pair of distinct movements, reducing accidental triggers when the iPad is picked up or tapped.
• Medium and stronger movements register as a single deliberate shake.
• A short cooldown prevents repeated changes from the same physical motion.
• The screen does not flash; listen and watch the controls for the variation.

Scope

Shake clears the current factory/user selection because the result is now a modified patch. Use Write immediately if a variation is worth keeping.

19. MIDI, MPE, CC Learn, and Host Automation

Hosted MIDI

In GarageBand, the host keyboard, recorded regions, sustain, transport, and external MIDI routing are supplied by GarageBand. VMEGAfm receives the events delivered to its instrument track. Other hosts may provide channel filters, MIDI processors, clock settings, and MPE routing.

MPE

VMEGAfm expects lower-zone MPE with master channel 1 and member channels 2-13. It supports per-note pitch bend at ±48 semitones, member-channel pressure, and accepts CC74 input for controller compatibility. Pressure can drive any one of the three LFO buses, allowing linked operator parameters to respond per note. There is no separate CC74/timbre destination on the panel.

MPE only works when the host preserves and routes member-channel expression. If notes disappear or expression becomes monophonic, test with MPE off, then check the host/controller's lower-zone channel range and track routing.

FS CC Learn

1. Connect or route a MIDI controller to the standalone app.
2. Tap cc learn.
3. Tap a knob or fader. Its target halo pulses blue.
4. Move a controller sending standard CC 1-127 with a value above zero.
5. The number appears over the target. Repeat or leave Learn.

Value 1 maps to minimum and 127 to maximum; 0 is ignored. The reverb flap opens temporarily so Mix/Size can be assigned. The hosted AUv3 editor does not show CC Learn because MIDI mapping is normally managed by the host.

Host automation parameters

The AUv3 exposes the same 41 sound parameters as the desktop plug-ins, in this order:

Host automation moves the base value. LFO modulation then moves around that base and clips at minimum/maximum. Automation, host presets, and GarageBand regions are saved by the host song rather than by VMEGAfm's XML user bank.

20. Performance and Latency

GarageBand and other hosts share the iPad's available performance across every instrument, effect, and track. VMEGAfm automatically balances its visual feedback and sound processing to help playback remain stable; no additional setup is required.

If audio crackles

• Stop touching a rapidly modulated control and check whether the host is close to its session limit.
• Freeze/bounce other instruments or disable unneeded effects.
• Reduce long reverb and dense 12-note chords while testing.
• Close background audio apps and reconnect a stable wired audio interface if the current route is unreliable.
• Test the same patch in FS. If FS is clean, the issue is likely total host-session load or buffer pressure.

21. State, Storage, and the Files App

Deleting VMEGAfm can remove locally stored settings and user presets. Export the user bank before deleting or reinstalling the app, or before moving to another iPad. A host song is not a substitute for an exported portable bank.

22. Troubleshooting

VMEGAfm is not listed in GarageBand

• Launch the standalone VMEGAfm app once.
• Quit and reopen GarageBand.
• Restart the iPad if Audio Unit registration has not refreshed.
• Confirm iPadOS 15 or later and that VMEGAfm has not been offloaded.
• In GarageBand, add it from External > Audio Unit Extensions as an instrument.

Factory names are visible but the patch does not change

• Complete a tap without scrolling; a drag is treated as browser navigation and intentionally does not load.
• Check whether host automation immediately writes old values back over the new preset.
• Close/reopen the AUv3 view and test factory 01 versus a dramatically different sound.
• Restart the host if its open VMEGAfm window does not refresh after reinstalling the app.

User presets are present in FS but not hosted, or vice versa

• Close and reopen the preset browser so it refreshes the shared VMEGAfm library.
• Close/reopen the host if the extension was already running when the bank changed.
• Export an XML backup before troubleshooting a replace/import operation.

Notes are missed in GarageBand

• Test MPE off first. A mismatched MPE zone can look like missing notes.
• Check the GarageBand track keyboard range, scale/chord mode, sustain, and MIDI input route.
• Reduce session CPU load and test with 01 Clean(ish) Sine.
• Confirm the arp Rate is not zero when an arp mode is selected.

Reverb controls disappeared

No Reverb is on. In FS it holds the flap shut; in hosted Voice it hides the entire Reverb frame. Turn No Reverb off in Settings to restore Mix and Size.

The screen is locked to landscape

This is intentional for the FS app. The panel is not designed for portrait. A host controls its own surrounding orientation, but VMEGAfm's compact editor remains arranged for a wide instrument view.

The 440 Hz tone continues

Tap the tone button again or close Settings. VMEGAfm stops both tuning sources automatically when leaving Settings.

23. Glossary

AUv3

Apple's Audio Unit plug-in format used by VMEGAfm inside iPad hosts.

Host

GarageBand, Logic Pro for iPad, AUM, or another app that loads the AUv3 instrument.

Algorithm

The routing of four operators into modulators and audible carriers.

Carrier

An operator heard directly at the output.

Modulator

An operator that changes another operator's spectrum through frequency modulation.

Total Level

Operator strength. Higher values mean a stronger carrier or modulator.

Multiply

Operator frequency ratio relative to the played note.

Feedback

Operator 1 modulating itself to add harmonics or noise.

Link

A route from LFO1, LFO2, or LFO3 to a parameter.

Ghost

The translucent effective knob/fader position created by modulation.

Retrig

Restarting an LFO when a new note or arp step begins.

LFO Loop

Repeating an LFO cycle instead of stopping after one pass.

Operator Loop

Repeating one operator's ADSR cycle while a note is held.

MPE

MIDI Polyphonic Expression using separate member channels for per-note pitch and expression.

Slide

Vertical position on an FS onscreen key, sent as poly aftertouch through LFO3.