Blind Mode

Blind Mode keeps the Fusor player sending control changes to the DJ app and makes it ignore anything that comes back: deck state, volumes, tempo, crossfader position, all of it.

Use it when the DJ app doesn't send MIDI feedback (djay Pro most notably), when no DJ app is running at all, or to rehearse transitions without telemetry in the loop.

It starts two ways. You turn it on yourself with the Blind Mode switch in Settings, or Fusor Studio switches to it automatically when a control-state check fails, so a transition can still arm without a working return path. Both behave the same while they're on, covered under What Blind Mode changes below. What differs is how each one ends, covered under What happens when capture can't reach the DJ app. Either kind is off again at the next launch.

When to use it

You're mixing with djay Pro or another app with one-way MIDI.
Your MIDI mapping sends controls but doesn't return deck state.
The host DJ app isn't running and you want to rehearse transitions.

If your DJ app sends full state (Traktor with the standard mapping, for example) and is running, leave Blind Mode off.

Turning it on and off

Open Settings → Connection and toggle the Blind Mode switch in the DJ app card. Blind Mode cannot be turned on or off during a run.

It does not persist. Every launch starts with Blind Mode off.

Turning it off runs a fresh capture automatically, because the control baseline you were using while blind was a stand-in rather than anything read from the DJ app. If you're armed and waiting when you turn it off, that capture waits until you disarm, rather than interrupting a transition that's about to start on its own. While it waits, the status line shows a RECAPTURE PENDING — prefix in gray, so you can see the refresh is owed. See The Player Window for how that prefix reads against BLIND and UNCAPTURED.

Changing the MIDI bus turns it off for you, says so on the status line, and runs a capture from the new bus straight away. No other event turns Blind Mode off without you. If the new bus is also silent, the capture fails and Fusor Studio switches back to automatic Blind Mode, exactly as it would at launch.

What happens when capture can't reach the DJ app

When a Control State Capture fails, from the Capture State button, Connect and sync or Resync in Settings, or turning an automatic Blind Mode off, Fusor Studio switches to Blind Mode automatically. The status line reads BLIND, with the failure named underneath: the common case (no MIDI from the DJ app at all) reads Blind Mode: no MIDI from Traktor, naming whichever DJ app you're running; the other two read Capture failed: no deck state and Capture failed: see Settings. See Status Messages for CAP3, CAP6 and CAP7 in full.

This automatic Blind Mode behaves exactly like one you turn on: the same default baseline, the same disabled list below. What differs is how it ends.

It keeps waiting for MIDI from the DJ app. There's no poll: Fusor Studio waits for the DJ app to send something. Traktor, for example, sends nothing while idle, so the first message it produces is your first touch on it after reopening it. The moment Fusor Studio receives that message, the status line reads MIDI from Traktor: Blind Mode off (CAP9), Fusor Studio leaves Blind Mode, and a fresh capture runs.

If that capture succeeds, you're running on a real baseline again.
If it fails too, Fusor Studio switches back to Blind Mode, this time no longer waiting for MIDI: touching the DJ app again does not start another attempt.
If your DJ app asks for consent before writing a baseline (every supported app except Traktor), it asks again at this point. Declining leaves Fusor Studio in Blind Mode and no longer waiting for MIDI, the same as a failed capture.
If Manual or Mixed Run Mode was on when Fusor Studio switched to Blind Mode, leaving restores it. Switching to it forces Auto Run Mode, the same as turning Blind Mode on does.
If a transition is armed or running when MIDI from the DJ app arrives, leaving waits until the run ends, the same wait described under Turning it on and off above.

End it by hand at any time, whether or not Fusor Studio is still waiting for MIDI: turn off the Blind Mode switch in Settings → Connection, or press Connect and sync on Settings → Connection. Either leaves Blind Mode and runs a capture. Settings → Connection also shows which kind of Blind Mode you're in: an automatic one keeps a red light and the failure's sentence, with Connect and sync offered; a Blind Mode you turned on shows a plain gray light with neither. See Settings → Connection.

The same applies with no DJ app configured: capture is skipped, arming is blocked, and the status line points you at Settings. Choosing an app runs capture automatically. Declining a consent request on an ordinary capture leaves you uncaptured too; only a failed capture switches Fusor Studio to Blind Mode.

Requesting a capture while Blind Mode is on is skipped, with a note saying so, because Blind Mode ignores the telemetry a capture reads.

It disables the parts of Fusor Studio that need to read DJ app state. Most of it is transparent; transitions start and run as normal. A few features need state and are unavailable:

Disabled

All inbound telemetry. Deck-playing state, volumes, tempo, and crossfader CC are all ignored at the MIDI entry point.
Manual and Mixed Run Mode. Without crossfader CC there is no input to drive progress, and a Mixed run would stop at the mix point with nothing able to resume it. Blind Mode forces Auto Run Mode on entry and locks the Run Mode switch at Auto. A press on Mixed or Manual does nothing except show Blind Mode: Auto Run Mode only on the status bar.
Deck-playing guard. Transitions can start without the outgoing deck reporting "playing". The Fusor player assumes you've started the track.
Snapshot / Restore. The player captures pre-transition control positions and restores them when a transition completes. Without telemetry there are no pre-transition values to capture, so Restore does nothing and those controls stay where the transition left them.

A domain set to Home still sends its outgoing controls to their home positions, because that needs no baseline: the neutral position is a property of the control. Out of the box that means the outgoing FX Unit still closes itself at the end of a Blind Mode run. See Domains → End of run. You will see it reported as CTL8-Sent home (n): unconfirmed rather than as a plain success, because in Blind Mode nothing comes back to confirm it arrived.
ERA (curve adjustment) and per-control soft takeover. With telemetry, the player adapts the start of a transition to where the controls actually sit: if the crossfader is already at 50% when a transition starts, it picks the curve up at 50% rather than jumping to the authored start. Without telemetry it can't see where any control is, so this adaptation is off. Every control starts at its authored value, including the crossfader. If your crossfader is at 50% and the curve's authored start is 0, the next CC sent will be 0; your hardware soft-takeover (or a careful hand) needs to handle the jump.
Manual takeover detection. Even if the DJ app sends crossfader CC, the player ignores it here, so it does not detect a hand on the crossfader mid-transition.
Tempo Ramp. The Tempo Ramp button is disabled and shows a tooltip. The ramp needs telemetry to confirm the deck reached its target tempo, and Blind Mode ignores telemetry, so the toggle refuses whatever fusor is loaded. Tempo ramp is a setting on the toggle, not something a fusor includes.
WAIT_UNTIL action steps. These fail fast with an error rather than timing out silently. WAIT_UNTIL watches a state value the player isn't receiving.
Role resolution from deck state. The player can't pick incoming/outgoing decks by watching volume faders. Set them with the Swap button. If Fusor Studio switched to Blind Mode after a failed capture, Connect and sync on Settings → Connection also detects them; in a Blind Mode you turned on, that button is hidden.
The tempo polarity test in Guided Setup. It exists to check whether telemetry works, so it asks you to turn Blind Mode off rather than quietly switching it off for you.

If you have a working bus, leave Blind Mode off. If you don't, turn it on and use Auto Run Mode.

Arm button behavior

Blind Mode leaves one way to start a transition: the press-Play default. The Arm button shows PLAY, and pressing it starts the transition. There is no separate arm step. The Start-with-Incoming opt-in is disabled here, because waiting for the incoming deck to start means watching telemetry. See Start-with-Incoming for what that does to a preference you already had set.

Completion

Transitions auto-complete at 100%. There's no deck-stop telemetry to wait for, so the engine finalizes on its own. The "reach 100% but stay live" behavior from Manual Run Mode doesn't apply, since Manual Run Mode is unavailable here.

Completion is completion: deck roles swap on their own, exactly as they do while Online. Manual Role Swap is there for the cases where the roles end up wrong: an aborted transition, or a track you swapped by hand.

Status line

While Blind Mode is on, state text is prefixed with BLIND – in gray, for example BLIND – Unarmed. Gray rather than red, because the missing telemetry is intentional.

djay Pro sends controls out but does not send deck state or tempo back over MIDI. Blind Mode is the supported way to control it from Fusor Studio:

Set up your djay Pro MIDI mapping to receive Fusor Studio's output. (Crossfader feedback from djay Pro is ignored here, so you don't need bidirectional crossfader, and Manual Run Mode isn't available either way.)
Turn the Blind Mode switch in Settings → Connection on. Do this each session, because it is off at every launch.
Build fusors whose actions don't use WAIT_UNTIL steps; those steps refuse to run here. Tempo ramp lives on the toolbar toggle, which is disabled in Blind Mode.
Start transitions with PLAY as normal. The Fusor player won't block on deck-playing state, and manual takeover won't auto-trigger.
Roles swap automatically when a transition completes. If they end up wrong, after an abort or after you reload decks by hand, click the Swap button in the toolbar to swap them. See Manual Role Swap.

Two things to check

A fusor whose actions use WAIT_UNTIL will not run blind. Test it against a two-way mapping first. The same goes for any run you would arm with the Tempo Ramp toggle on, because the toggle is unavailable here.
A capture that fails at the start of a session switches Fusor Studio to automatic Blind Mode, and that means the return path is not working. To see whether Fusor Studio is receiving state at all, leave Blind Mode off (or end the automatic one) and watch the status line; with Blind Mode on, incoming MIDI is ignored, so the line does not respond to it.