MPC4000 OS 1.81 user guide

Before you start

CHOP: turn a performance into Regions

SAMPLE › REGION

CHOP lets you create Region boundaries by tapping pads during sample playback, or split and merge Regions precisely with ADD and DEL. It changes the sample's Region map, not the underlying audio.

Enable CHOP

1. Select the sample and open SAMPLE › REGION. If you want to chop from scratch, begin with one Region covering the desired sample area. Enabling CHOP does not erase existing Regions.
2. Hold SHIFT. The alternate footer shows CHOP:OFF, CHOP TO, ADD and DEL.
3. Press F1 to select CHOP:ON, then release SHIFT. The CHOP controls remain visible while the mode is on.

Create markers with the pads

1. With a single full-length Region, press PAD A1 to start its playback from the beginning.
2. As the next sound begins, press PAD A2. Because Region 2 does not yet exist, the press creates its start marker at the current playback position. Region 1 ends immediately before it.
3. Continue with PAD A3, PAD A4 and so on. Use the next unassigned Region pad for each new cut.
4. Press an already assigned pad to select and restart that Region. This is an audition, not another cut. Repeated presses restart the preview instead of layering it.

Pad-to-Region mapping

After a successful new cut on A16, B16, C16, D16 or E16, CHOP automatically selects the next bank, so you can continue on its first pad. Auditioning an existing 16th Region does not switch banks. Bank F is the last bank and does not wrap back to A.

ADD: split at a precise sample position

Use ADD when you know the exact cut position or want to refine a chop numerically.

1. Select the Region you want to divide.
2. Move the cursor to Region END and set it to the position where the new Region should begin.
3. Press F5 ADD. The new Region is inserted immediately after the selected one; later Regions are renumbered.

DEL: merge with the previous Region

1. Select the Region you want to remove from the Region map.
2. Press F6 DEL. Its range is merged into the preceding Region, and later Regions move down by one number.

CHOP TO: Threshold

For automatic marker placement, press F4 CHOP TO in the CHOP footer, or hold SHIFT and press F4 on the REGION page.

Up to 96 Regions can be created. The first and last Regions cover the outer analysis boundaries. Stereo channels use the same marker positions. If a boundary is not where you want it, select that Region and refine START/END manually.

Leave CHOP

Press F1 to select CHOP:OFF and release SHIFT to restore the standard footer. Leaving SAMPLE › REGION also switches CHOP off automatically. The Region markers you made remain.

Non-Destructive Slice

SAMPLE › REGION › EDIT › SLICE SAMPLE

Non-Destructive Slice (NDS) creates a program whose pads play Regions of the original sample. It does not render a separate audio fragment for every pad. You can return to the source sample and change a Region's boundaries later.

Create an NDS program

1. Prepare the source sample's Regions manually, with pad chopping, or with CHOP TO.
2. If CHOP is on, switch it off and release SHIFT so the standard footer returns. Press F5 EDIT.
3. Choose SLICE SAMPLE in the Edit field.
4. Set Generate sequence: NO for a program-only workflow, Create new program: YES and Non-Destructive: YES.
5. Press F6 DO IT. Select the new program in PROGRAM or assign it to the desired Multi part, then play the Region pads.

Refine the chops after making the program

Open the original source in SAMPLE › REGION. Select a Region and adjust START or END. The linked NDS pad uses that Region, so there is no need to run SLICE SAMPLE again for every boundary correction.

With CHOP enabled, ADD and DEL also update the linked NDS Region assignments. For a regular, non-NDS program, the Region map alone does not rebuild the program: run SLICE SAMPLE to create new sliced assignments.

Playback still uses the PROGRAM settings

NDS is not a forced one-shot mode. PROGRAM › ZONE › Play mode still controls playback:

• ONE SHOT — plays the Region without requiring the pad to stay held.
• NO LOOP — gated, non-looping playback with the normal envelope and note-release behavior.
• LOOP — uses the Region boundaries for looping, with the normal gated/envelope behavior.
• AS SAMPLE — follows the source sample's play mode. If the source itself is one-shot, AS SAMPLE stays one-shot; it does not force a hold-to-play mode.

Save the source together with the program

At STOP, save the program WITH SAMPLES, or save the project with its programs and samples. Keep the AKP and the original source WAV together: the program links and the source Region metadata are both needed to rebuild the NDS mapping.

If you changed markers and a WAV with the same name already exists, save the updated source too — skipping its replacement can leave old marker data on disk. Keep a separate backup before overwriting an earlier version, and reload on OS 1.81.

Edit: ONE / ALL / ADD

PROGRAM › KG MIX / PITCH / EDIT 1 / EDIT 2 / ZONE

The SHIFT + F6 shortcut exposes the MPC4000's existing shared Edit setting directly on all five pages. You no longer need to move to EDIT 1, EDIT 2 or ZONE just to change the edit scope.

1. Open one of the supported PROGRAM pages.
2. Hold SHIFT. The rightmost button becomes Edit:ONE, Edit:ALL or Edit:ADD.
3. Press F6 to cycle to the mode you need. Each press advances once.
4. Release SHIFT and edit the parameter as usual. The cursor stays in place and the chosen Edit mode remains active.

ONE: edit one keygroup or note

Only the selected keygroup/note is affected. Use this for tuning, level, filter or zone adjustments on a single pad.

ALL: set the same absolute value

Edits apply the same absolute value across the program's keygroups/notes. Use this when you want a common starting point, such as the same tuning or envelope setting.

ADD: apply the same relative change

Edits adjust keygroups/notes relative to their current values, keeping the differences between them where the parameter supports relative editing. Useful for an overall boost, cut or tuning shift after individual adjustments.

The setting is shared across the supported pages, not stored separately for KG MIX and PITCH. Switch back to ONE before a change meant for only one note. These are program-parameter edits, not destructive edits to the sample's audio.

ONE / ALL / ADD keep the original Akai editing semantics — see the Akai MPC4000 User Guide, printed page 86.

Monitor: DIRECT

RECORD › Monitor: DIRECT

DIRECT keeps the selected external input audible when you leave RECORD and work in MAIN or other menus. Use it to listen to an instrument, a turntable preamp, a mixer or another line-level source while operating the MPC.

OFF, ON and DIRECT

Enable continuous input monitoring

1. Turn down headphone and monitor-speaker volume. Connect the external source to the intended MPC input.
2. Open RECORD. Set Input Source to the connected input (ANALOG IN in these examples). Check that the input is present before leaving RECORD.
3. Choose Mode and Bit as needed: STEREO for a stereo source, or the matching mono-input mode for a single channel.
4. Move the cursor to the Monitor field and turn the data wheel from ON to DIRECT. The checkbox is checked for both ON and DIRECT; there is no separate DIRECT switch.
5. Press MAIN or open another menu. The input should stay audible without pressing a pad or starting a recording.

Which settings are used?

Use the RECORD Q-FX processing

1. In RECORD, press F4 Q-FX.
2. Choose the Q-FX processing mode and settings, including the input Send where applicable. Check the sound while you are still in RECORD.
3. Keep Monitor: DIRECT selected and leave RECORD. The DIRECT input keeps the RECORD Q-FX processing instead of switching to a dry path.

To change the processing, return to RECORD and adjust Q-FX there. Q-FX OFF gives the unprocessed input.

Turn DIRECT off

Return to RECORD and set Monitor to ON for RECORD-only monitoring, or OFF to mute input monitoring. Unlike CHOP, DIRECT does not switch off when you leave its page. The DIRECT choice lasts for the session only: select it again after a power cycle.

Quick reference

Saving and practical notes

• Back up first, and don't open old projects in 1.81. Keep projects from other OS versions on a separate backup and on the OS they were made with — re-saving them in 1.81 can damage them.
• Keep a copy before CHOP TO. CHOP TO replaces the current Region map; save a copy if you may want the earlier markers back.
• Save at STOP. Stop the sequencer before saving a whole project and before checking a fresh reload.
• No more than 96 Regions. CHOP does not create a 97th Region. Use another source or merge existing Regions when you reach the limit.
• Keep coordinates straight. START/END are per-channel sample positions with inclusive ends. Neighbouring Regions meet at previous END + 1.
• Markers are not slices. Editing the Region map does not rebuild a normal program; an NDS-linked program follows its source Regions.

Troubleshooting

The LCD images are unmodified emulator captures of the interfaces used by OS 1.81; the RECORD images come from the retained v31 DIRECT implementation. Demo names and sample lengths are illustrative. They are not photographs of a physical MPC, nor a guarantee for every hardware, audio or project-loading case. This is an independent guide, not an official Akai manual.