Colosseum

A Modern Modular Audio Playground — Built for Musicians Who Think in Signal Flow

Colosseum is a lightweight, standalone audio host that puts your entire plugin collection at your fingertips. No DAW timeline, no arrangement view, no clutter. Just a clean, visual graph where you wire things up, experiment, and play. Colosseum runs as a native desktop application with rock-solid ASIO support on Windows and CoreAudio on macOS (only ASIO and CoreAudio drivers are supported). It's designed for live performance, jam sessions, plugin auditioning, and anyone who wants to run their plugins without the overhead of a full DAW and with minimal system requirements.

The Graph — Your Signal Flow, Your Way

At the heart of Colosseum is a fully interactive node-based routing canvas. Every plugin, every I/O point, every utility tool lives as a draggable node on an open canvas. Connections are drawn visually between audio and MIDI pins. What you see is exactly what you hear.

Multi Audio Input/Output Routing

Get the best out of your audio interface's inputs and outputs on stage. Route anything you want to whatever you want. Get the best out of your loopback streams. Send your session to simultaneous virtual or physical destinations or instantly receive audio sources from other apps. Be it a live show, jam, podcast, TikTok story, whatever — all those options are available simultaneously.

Splits

Fan-out routing is natively supported: split one output to feed multiple plugins simultaneously. Sidechain-capable plugins are automatically detected and their sidechain inputs are exposed as dedicated pins on the graph. Just drag a cable to the sidechain input and it activates. No menu diving, no bus configuration dialogs.

Instrument Switching / Combining by a Single Pad Button Press

Each VSTi opened in Colosseum automatically gets a selector button attached to a MIDI key. This method allows users to link their hardware keyboard's pads and switch between instruments on stage during a live show instantly. The low-value key numbers ensure zero clashes between playing notes and controlling (MIDI keys 1 to 32).

Workspaces — 16 Independent Sessions in One Window

Colosseum gives you 16 switchable workspaces, each holding its own complete graph — plugins, connections, node positions, bypass states, everything. Think of them as 16 separate rigs living inside a single instance. Jump between a synth rig, a guitar pedalboard, and a vocal chain with one click. Rename them, enable or disable them, and switch mid-performance without missing a beat. All workspaces save and restore as part of your patch file.

Modular Recording

Record only what you need, the way you want. Create any combination of separate or synced recording sessions with the in-graph recording node. Drop as many recorders into the session as you want. Switch between them to record different simultaneous stems on each session's timeline.

Sampling — Manual and Automated

Colosseum includes two dedicated sampling nodes that turn your plugin chain into a sample-harvesting machine:

• The Manual Sampler arms itself and waits for a MIDI note-on. Play a note, and it records the audio flowing through the chain until silence is detected — then auto-names and saves the file by note, octave, and velocity. Perfect for capturing one-shots from any plugin in your graph.
• The Auto Sampler takes it further. Define a list of notes, velocities, and durations using a simple text syntax, hit start, and Colosseum plays through every combination automatically — firing MIDI notes, capturing the resulting audio, and saving each sample to disk. Walk away and come back to a complete multi-sampled instrument folder. No third-party sampling tools needed.

MIDI File Player

Drop a MIDI Player node onto the graph and load any standard MIDI file — Type 0 or Type 1. Full transport controls: play, pause, stop, loop, and seek with position scrubbing. All 16 MIDI channels output simultaneously, with per-channel mute toggles and instrument detection. Tempo follows the embedded MIDI tempo map or locks to your master BPM. Controller state snapshots ensure clean seeking without stuck notes — jump to any point in the file and every CC, pitch bend, and program change snaps to the correct state instantly.

CC Step Sequencer

A 16-slot CC step sequencer that lives on the graph like any other node. Each slot targets a specific CC number and MIDI channel with adjustable step counts (2 to 128 steps), rate divisions from whole notes down to 1/128, triplet and dotted modes, and five playback orders including ping-pong, random, and drunk walk. Swing, smoothing, and speed controls per slot. Syncs to master BPM and time signature. Wire it into any plugin's MIDI input and automate filter sweeps, modulation, expression — anything that responds to CC, controlled from a visual step grid you can draw on in real time.

Transient Splitter

A zero-latency transient detection node that splits incoming stereo audio into two separate stereo pairs: transients (attacks) and sustain (tonal body). Four outputs — transient L/R and sustain L/R — each routable independently on the graph. Feed the attack into a compressor and the sustain into a reverb. Process drum transients and room tone separately. Shape the balance between punch and body without any phase artifacts. Real-time envelope follower detection with adjustable sensitivity, hold, and crossover controls.

VST2 Support

Need that one classic plugin that never got a VST3 update? Colosseum lets you load VST2 plugins directly from a file browser — point it at any .dll (Windows) or .vst bundle (macOS) and it drops straight onto the graph as a fully functional node. Same metering, same bypass, same MIDI channel filtering as every other plugin. Configure your VST2 folders in the Plugin Manager and they're always ready to go.

Storing

The graph supports full preset save and recall. Your entire routing — every plugin, every connection, every node position, bypass state, MIDI channel assignment, and workspace — saves into a single patch file and loads back exactly as you left it.

Plugin Hosting — Fast, Safe, and Format-Aware:

• Colosseum hosts VST3 plugins on Windows and both VST3 and Audio Unit on macOS. VST2 plugins are supported via direct file loading on both platforms. A built-in plugin scanner discovers your installed plugins with background metadata collection: vendor names, categories, instrument vs. effect classification — all gathered without freezing your UI.
• Plugins that misbehave during scanning are gracefully handled with timeout protection, so a single bad plugin won't take down your session. A dedicated Plugin Manager tab lets you add custom scan folders, trigger rescans, and manage your plugin library.
• The Plugin Browser Panel sits as a fixed sidebar next to the graph canvas, organized by vendor and category. Drag a plugin straight from the browser onto the canvas to instantiate it — or right-click anywhere on the graph for a quick-access plugin menu.

Every Plugin Gets Superpowers:

• Each plugin loaded into Colosseum is wrapped in a smart processing layer that adds capabilities the plugin doesn't have on its own:
• Per-plugin MIDI channel filtering — Route specific MIDI channels to specific plugins. Run a bass synth on channel 1, a pad on channel 2, and a lead on channel 3 — all from the same MIDI input.
• Per-plugin bypass and freeze — Bypass a plugin to silence it while keeping it loaded, or freeze it to completely suspend its processing and free up CPU.
• Pass-through mode — Let audio flow through a plugin's node without processing, useful for A/B testing.
• Crash isolation — If a plugin crashes, Colosseum catches it and keeps the rest of your session running.

Hardware MIDI — Channel Duplication Engine

Colosseum's MIDI input system goes beyond simple pass-through. Each connected MIDI device gets its own channel mask configuration. In the default mode, all 16 channels pass through untouched. But select specific channels and Colosseum enters duplication mode — incoming MIDI is replicated across all selected channels simultaneously. This means a single keyboard can drive multiple instruments on different channels without any external MIDI routing tools. Channel changes send automatic All-Notes-Off messages to prevent stuck notes — even when switching masks on the fly during a live set. MIDI outputs are independently configurable with their own channel masks, giving you full control over what goes where.

Built-In Tools

Colosseum includes a set of utility processors that live on the graph alongside your plugins:

• Recorder — Drop a recorder node anywhere in the signal chain to capture audio at that exact point. Records directly to disk using a threaded writer for glitch-free operation. Multiple recorders can be synced to start and stop together. Supports a global recording folder with per-instance override.
• Manual Sampler — Arm it, play a note, and it captures the audio until silence. Auto-names files by note, octave, and velocity.
• Auto Sampler — Define notes, velocities, and durations in a text editor. Hit start and walk away — Colosseum builds your sample library automatically.
• MIDI Player — Load any .mid file and play it back through your graph with full transport, per-channel muting, and clean seeking.
• CC Step Sequencer — A 16-slot visual step sequencer for automating any CC parameter. Draw patterns, set rates, and sync to master tempo.
• Transient Splitter — Split audio into transient and sustain components with four independent outputs for parallel processing.
• Stereo Meter — A visual stereo level meter node for monitoring signal levels at any point in your chain.
• MIDI Monitor — See incoming MIDI data in real time — note numbers, velocities, CC values, channel info.
• Simple Connector — A transparent pass-through node for organizing complex routing layouts.

Mixer View

Switch to the Mixer tab for a traditional channel-strip view of your I/O. Per-channel input and output gain faders give you control over up to 64 channels of audio. The mixer reads directly from your audio interface's channel names, so you always know which physical input or output you're adjusting.

Tempo, Time Signature, and Metronome

A dedicated transport section provides master tempo control (20–300 BPM with 0.01 precision), tap tempo, configurable time signature (up to 16/16), and a built-in metronome with adjustable volume. These values are available to all hosted plugins that read host tempo information.

Live Performance Ready

Colosseum is built with the stage in mind:

• ASIO-first architecture — Sample rate and buffer size are controlled by your audio interface, not by Colosseum. Whatever your driver is set to, Colosseum follows.
• Multi-channel I/O — Supports whatever your interface provides, from a simple stereo pair to 64-channel setups.
• Instrument Selector — A quick-switch panel for jumping between instruments in your graph during a live set, with multi-mode support for layering.
• Virtual Keyboard — A built-in MIDI keyboard window for quick testing when hardware isn't connected.
• MIDI Panic — One-click All-Notes-Off and All-Sound-Off across all channels and all loaded instruments. Stuck notes are history.
• Audio and MIDI kill switches — Instantly mute audio input, audio output, or MIDI input from the header bar.
• Built-In Manual.
• Need to know anything about Colosseum? Just switch to the Manual tab and you'll find everything you need to know. No PDFs, no external text files. It's all right there, always.
• Main Features.
• ASIO and CoreAudio support.
• Full preset system with XML-based patch files.
• 16 switchable workspaces per session.
• VST3, Audio Unit, and VST2 plugin hosting.
• Real-time CPU and RAM monitoring in the header bar.
• Custom dark theme designed for low-light environments.
• Persistent settings — audio device, MIDI masks, plugin library, recording folder, and window state all saved as part of the session file.
• Multi-MIDI routing through MIDI channels — everything connects to everything. One hardware instrument controls many plugins, a bunch of hardware instruments control a single plugin.

Everything is possible.