Known limitations

• LSP’s Multi-Sampler: now and then one of its samples doesn’t load, and that instrument stays silent. Load the plug-in again, or close and reopen the project.
• Platforms: plug-in editor windows open on Linux (X11) and macOS; Windows (HWND) embedding is planned. On macOS, keys a plug-in’s window doesn’t use itself (Space, R, other key commands, Musical Typing) go to Marbble, while typing into the plug-in’s own fields stays there; Esc doesn’t close the window. On Linux only menu shortcuts work while a plug-in’s window is in front. The input level check is Linux only. On Windows and macOS only the system’s default audio driver is available (no ASIO).
• Plug-in formats: VST3 only; no CLAP, AU or VST2.
• Tempo: a region’s length stays in samples when it is moved across a tempo change (only its start follows the bars and beats). Move MIDI Regions with Tempo doesn’t move automation or markers, isn’t applied to base-tempo edits in Project Settings, and isn’t remembered between sessions.
• Arrangement track and section edits: moving, copying or deleting a section, and the Section Between Locators commands, leave the tempo and signature tracks as they are, and refuse to cut a frozen track’s regions.
• Editing: region gain bottoms out at -96 dB (shown as −∞), not true silence. Snap Edits to Zero Crossings doesn’t apply to fades or to take folders. The Shuffle and No Overlap modes don’t apply to range edits in the Audio Track Editor, Repeat, or Move to New Track. Apply Last Fade and fading a marquee selection aren’t implemented. Strip Silence leaves take folders alone.
• Crossfades: muted regions don’t crossfade (they fade out as Out). A crossfade’s handle can’t be grabbed where the incoming region is drawn over it (an overlap with the newer region on top); use the Inspector. The Inspector’s fade rows edit the one selected region.
• Take folders: an audio recording without Cycle over a folder doesn’t add a take to it, and recording a cycle adds to a folder only when it covers exactly the same range. A folder’s own fades shape only its first and last comp stretch. With Autopunch inside the cycle, a punch-out closer to the cycle end than the recording latency makes each take that much shorter. MIDI take folders play one whole take, as in Logic (no swipe comping).
• Plug-in delay compensation: the mix plays behind the playhead by the total latency rather than reading regions early, so live input on a monitored track that isn’t recording is delayed with everything else (Low Latency Mode avoids that). Low Latency Mode only switches off plug-ins on the live track itself, not on the auxes or stacks it plays through. Fader automation written live is stored at the playhead, not compensated.
• Mixer: VCA levels can’t be automated. A side-chain key is taken as the source leaves its plug-ins, so latency on the source’s own plug-ins makes the key arrive that much late.
• Built-in effects: bounces keep the tail length set in the Bounce dialog whatever an effect’s own tail; Freeze stretches its tail to the longest one. VST3 user presets aren’t saved by Marbble (use the plug-in’s own). The Linear Phase EQ follows automation in steps of about 25 ms.
• Separate windows: the analyzer follows one strip, so a Channel EQ in a separate window and another strip’s Channel EQ in the main window take turns showing it. On Linux under native Wayland (not the default), the compositor decides where windows open.
• Freeze renders from the track’s first region to its last plus up to 4 s of tail. A frozen track’s plug-in automation lanes stay editable but do nothing until it is unfrozen.
• Imports: a raw AAC stream (.aac, not in an M4A/MP4 file) and CAF files aren’t trimmed of their encoder delay; M4A/MP4 and MP3 are.
• Bounce: WAV, AIFF and FLAC only; MP3 and AAC aren’t offered.
• Automation: Move Automation with Regions works along a track, not for regions moved onto another track or copied; where it cuts a curved segment, the cut part is approximated. Automation curves are power curves only (no S-curves). A folder’s automation follows the folder’s own timing, not each subtrack’s delay compensation. Stereo Out’s lanes play at the output’s delay; with latency on Stereo Out’s own plug-ins, their parameters change slightly early.
• Controller assignments: control changes 0–119 and pitch bend only (no notes, NRPN or aftertouch), and no control surface protocols such as Mackie Control. Assignments are global and refer to tracks and plug-ins by number, not per project.
• Piano Roll: no Score. Controller curves are drawn as ramps of points; a curve between two points isn’t kept as a shape that can be bent later.
• Event List: lists MIDI regions only (not the regions of the project, or audio), on one track at a time. Marbble stores no MIDI channel, program changes, polyphonic aftertouch, release velocity or SysEx, so the Ch column always reads 1 and those types have no filter.
• Step Sequencer and Step Input: the Piano Roll and the Event List don’t show a pattern region’s notes (convert it to a MIDI region to edit them there). Step Input works only while the transport is stopped.
• Undo: the metronome and count-in switches and the project sample rate are not undoable, and switching the metronome doesn’t mark the project as edited.