Loading a fusor

Loading a fusor is how you set up the player. Pick a fusor, set the bars and BPM you want (if you're running in Auto Run Mode), and you're ready to arm.

You can load a fusor two ways: from the fusor picker in the player, or from the Fusors list view in the Library.

If you have Fusor Studio Plus, the usual path is to load a transition instead, and the linked fusor comes with it. See Loading a Transition in the Plus manual. Loading a fusor directly is still useful on Plus for one-off pairings without a transition record, and for authoring or testing fusors.

What "loading" means

When you load a fusor, Fusor Studio loads the fusor into the player and that's it. The Tempo Ramp setting already on the player is not changed, and the bars/BPM values (when shown) are not changed either.

• In Manual Run Mode the bars/BPM readout is not shown, since the crossfader drives the transition.
• In Auto Run Mode the bars/BPM readout is shown; check and set those values before arming, because Auto Run Mode uses them to time the transition.

Loading from the fusor picker

The fusor picker is the button in the picker row.

1. Click the fusor picker. The Library popover opens, focused on the active collection's Fusors sub-tab.
2. Click the fusor you want. The popover closes automatically and the fusor loads.

The popover shows every fusor in the active collection. To see fusors in a different collection, change which collection is active first (see below).

Loading from the Fusors list view

1. Click the Library menu in the menubar to open the Library popover. In the popover header, click Fusors. The Fusors section has two sub-tabs: Collections and Fusors. Switch to the Fusors sub-tab.
2. Use the search field, sort controls, and filters to narrow down to the fusor you want.
3. Right-click the fusor and choose Load, or double-click the row.

Each row also carries a small info icon on the right that opens the fusor's editable detail view directly. The right-click menu holds the rest of what you can do with a row:

To edit a fusor without loading it, use Details. Edits autosave, and the loaded fusor isn't affected. See Authoring Overview for the full editing model.

Filtering a list

The Fusors and Actions lists both carry a filter bar above the rows. It works the same way in both.

Adding a filter. Click + in the filter bar. Choose whether the filter should include or exclude, then pick what to filter by: a collection or DJ app for fusors, a pack or DJ app for actions. The list narrows immediately and the filter appears as a chip in the bar.

DJ App chips. Both lists carry a DJ App scope, with one chip per app in the tag registry ("Traktor," "Mixxx," and so on). A fusor or action that names no DJ apps is treated as working anywhere: an include chip never filters it out, no matter which app you've selected. An exclude chip only removes records actually tagged with that app, so an untagged record stays visible there too. In other words, an empty Apps field means "works with every app," not "works with none" — a record with no apps listed always stays in the list.

Removing a filter. Click the × on an individual chip to drop just that one, or the × at the right end of the bar to clear all of them at once.

Combining filters. Two filters of the same kind widen the result: filtering by two DJ apps shows records made for either one, and two collections show the fusors in either. Filters of different kinds narrow it: a collection chip plus a DJ app chip shows only fusors that are in that collection and made for that app. Excluded filters always remove matching rows from whatever the other chips selected. The one thing the bar can't express is "either" across different kinds — there's no way to ask for "in this collection or for Traktor."

Filters from a right-click. Right-clicking a collection and choosing Show Fusors (or a pack and Show Actions) adds a chip for it, exactly as if you had added it with +. Any filters already in the bar stay, so this widens the list rather than replacing what you were looking at. The bar always names everything currently being shown, and the × clears it back to the full list.

Changing the active collection

The active collection controls which fusors appear in the picker. To change it:

1. Open the Library popover from the menubar and switch to the Collections sub-tab (under the Fusors section).
2. Right-click the collection you want and choose Set Active.

The fusor picker will now show fusors in this collection.

When you can't load

You can't load a new fusor while a transition is running. The player locks during a transition. Once the transition completes or you abort it, loading is available again. See Transport Controls.

What you'll see when a fusor loads

After you load a fusor, you should see:

• The fusor picker now shows the loaded fusor's name.
• The bars and BPM values on the player are unchanged (they're shown in Auto Run Mode only). These are not part of the fusor itself.
• The Tempo Ramp toggle is unchanged. Loading a fusor leaves it wherever you set it on the menubar's transition group. By default the toggle resets to off at the end of each run, so in practice it's off unless you armed it; turn on Persist tempo ramp across transitions in Settings → General and it stays armed from one run to the next.
• A brief confirmation appears on the left side of the status line: "Fusor loaded: [name]".

Inspecting the loaded fusor — Session View

After a fusor is loaded, click the small info icon next to the fusor picker (see The Player Window) to open Session View. This is an inline panel that opens between the menubar and the picker row, so it appears above the player's controls; the window grows upward to make room for it, or downward when the player is sitting too near the top of the screen. It lets you read what the fusor will do (and make a few quick adjustments) before you arm.

Session View is a pre-flight staging surface: you load the fusor ahead of the run, read through it top to bottom, disable anything you don't want firing tonight, adjust your DJ app by hand if the preflight notes ask you to, and then arm. It shows only what belongs to the fusor itself: its intent, the domains it drives, and the actions it runs. Track- and tempo-specific detail (which only exists once a fusor is paired with two tracks in a transition) lives elsewhere.

Session vs record

Session View rests on a split. The fusor record is the .fusor file on disk; the session is this run, right now.

• The record is what the author saved. It only changes when you (or the author) explicitly save edits in the Library.
• The session is everything Fusor Studio remembers about the currently loaded fusor for the current run. Session edits live only here, in memory. They never write back to the .fusor file.

So you can take a fusor that's almost right for the moment and tweak it for this one run without permanently changing it: disable a domain you don't want firing tonight, swap which FX unit gets used because Unit 1 is busy, skip an action. When you load a different fusor (or reload the same one), your session edits are gone and the record's authored values come back.

The status line acknowledges session edits with the phrase "… for session" so it's always clear the change is transient (for example, "EQ domain disabled for session." or "Incoming now routes through FX Unit 2 for session.").

The chronological stack

Session View is a single stack of cards, read top to bottom in performance order, the same order things actually happen during the run:

1. Pre-run actions (if any) — fire before the transition starts.
2. Domains — the body of the transition. Domain cards are ordered by signal flow (stems, then EQ, filter, FX, mixer FX, and the channel fader last), not by the order the author added them.
3. Post-run actions (if any) — fire when the transition finishes.

Above the stack, a short header shows the fusor's name, and beneath it the author's intent: a concise statement of what this fusor is for. Clicking the name jumps straight to the fusor's detail page in the Library popover. (The intent line is only shown when the author wrote one.) The fusor's longer description and its authoring metadata — author, version, DJ apps — aren't here; they live on the fusor's detail page in the Library, off the performance surface.

Actions look different from domains. Action cards carry a coloured left border so you can tell at a glance which cards fire an action and which drive a domain, even though they share the same card shape.

What every card shows

Whether it's an action or a domain, each card collapses to the same three things:

• An orange enable Switch — flip it off to skip that card for this run.
• The name (domain name, or action name). For actions, clicking the name opens the action's detail page in the Library popover.
• The card's pre-run text, if the author filled it in. For a domain this is the author's reminder for what that one domain needs (for example, "Set the EQ knobs to centre before arming."); for an action it's the author's per-action note. Hidden when empty.

Only one card is open at a time. Click a card to expand it; opening another closes the first.

Expanding a domain card

Inside a domain's expanded panel you'll see the curves the domain will run, laid out in two columns, outgoing on the left and incoming on the right, so you can read what each side does. For FX-unit-typed domains, each side carries a small numbered picker that lets you choose which FX unit (1–4) that side routes through.

The FX-unit picker handles collisions for you: if you click a unit that's already taken by the other side, that side gives it up (you'll see its slot turn into an empty-state dashed orange box) and your side claims it. So you can re-balance FX routing on the fly without clearing the other side first. The change is a session edit, so the fusor file isn't touched.

Hover any curve label to see a tiny preview of the curve shape.

Expanding an action card

An action's expanded panel shows the action's body as a read-only DSL summary (the same text the action editor uses to display the steps). This is for sanity-checking what the action will do before you let it run. There's no editing here; open the action in the Library for that.

What "session edits" cover

There are three session-edit affordances in Session View today:

1. Domain enable / disable (Switch on a Domain row).
2. FX-unit reassignment (clicking a numbered unit in an FX-unit domain's expanded picker).
3. Action enable / disable (Switch on an Action row).

All three follow the same rule: they apply only to the currently loaded fusor for the current run, and they reset to the authored values the next time you load (or reload) the fusor.

The domain Switch here looks the same as the one on the Domains tab in the Library, and it means the same thing at a different scope. This one changes only the current run. The Domains tab switch changes how the fusor arrives every time it loads. See Domains → The enable switch.

When to use Session View

The typical flow is: load → read the intent line → scan down the stack checking pre-run notes → maybe tweak a domain or FX unit → arm. If you find yourself making the same session edit every time you load a particular fusor, that's a sign the fusor itself wants editing. Open it in the Library and save the change to the record instead.