Pitch, key lock & platter control

Everything that changes how fast (and in what direction) a deck spins, and how the app keeps the music sounding right while you do it.

The pitch fader and its three ranges

The pitch fader (printed PITCH) runs the deck's speed. It works across three selectable ranges:

• ±8% — the classic vinyl feel, finest control
• ±16% — wider swings for bigger tempo jumps
• ±50% — half-speed to 1.5× territory

Two ways to switch range:

• On screen: the range button on the deck button bar — the slot that reads 8% / 16% / 50% at the top of each turntable.
• On the hardware: press the Pitch Range button (printed RANGE) to cycle 8 → 16 → 50. Hold it for about two seconds instead to toggle the decimal display.

Your current pitch percentage is drawn right on the spinning record, next to the track's key and BPM, and each deck's live BPM readout sits in the record's groove band at the 9 o'clock position.

Key lock

Key lock keeps the music in its original key while the pitch fader changes the tempo — speed up or slow down a record without it going chipmunk or sludgy.

⚡ To toggle it (per deck), any of these:

• the key lock button on the on-screen deck button bar
• the hardware button printed KEY LOCK
• SHIFT + the Pitch Range button (printed RANGE)

The hardware button's LED blinks while key lock is engaged.

Platter speed: 33 and 45

The 33 and 45 buttons set the platter's base speed, and the on-screen 33/45 button on the deck button bar does the same. The app tracks which speed you're on — saved tempos and BPM readouts are adjusted for it automatically.

Motor off and wind-down

• START/STOP is the motor button — the classic turntable start/stop.

• The wind-down button sits right of the platter, printed SLIP with MOTOR OFF as its lower legend. Tap it and the record slows to a stop like the power was pulled.

• The Stop Time knob (printed STOP TIME) sets how quickly the platter brakes when you stop it.

Instant zero: the CENSOR button

In Skratch Attach the button printed CENSOR works as a pitch-zero toggle: press it and the deck jumps to a true 0% — the motor runs at exactly nominal speed and the display reads 0.00%, no matter where the fader sits. Press it again and the deck returns to your physical fader position. Key lock follows along correctly in both directions.

Reverse

The button printed REVERSE toggles motor reverse — the platter itself spins backwards until you toggle it off. Its LED blinks while reverse is engaged.

Good to know: the pitch bend buttons do something else

The buttons printed PITCH BEND + and PITCH BEND - are repurposed in Skratch Attach as pad volume up / down for the selected pad. Nudging tempo is what riding real vinyl is for.

BPM readouts and pitch calibration (advanced)

The per-deck BPM readout is a prediction: the analyzed tempo of the record on that deck, scaled by your platter speed and pitch fader. Real turntable motors don't always deliver exactly the fader percentage, so two decks matched to the same readout can still drift apart by ear.

Pitch calibration measures your actual motors and corrects the math, per deck:

1. Recall the deck's tempo-mapped record from the Tempo Library and play it.
2. Park the pitch fader at an offset you actually use (say −8% or +8%).
3. Open Analyze for that deck and capture 30–60 seconds of a steady section, then lay the grid as usual.
4. Press "SAVE CAL PT" in the analyze review controls (it confirms with "CAL SAVED").

Repeat at a couple of fader positions — both directions is best. A capture near 0% measures your motor's true zero point. From then on that deck's BPM readout reflects the measured motor, not the assumed one. Decks you haven't calibrated behave exactly as before.

See Tempo Library & record analysis for the capture and gridding flow itself.