Introduction
This manual provides essential information for the setup, operation, and maintenance of your MOSEN MS081 88-Key Portable Digital Piano Keyboard. Designed for beginners and experienced players alike, this semi-weighted, foldable keyboard offers a versatile and portable musical experience. Please read these instructions carefully to ensure proper use and to maximize your enjoyment of the instrument.
Package Contents
Verify that all items listed below are included in your package:
- 1 x MOSEN MS081 88-Key Semi-Weighted Keyboard
- 1 x Microphone
- 1 x Music Stand
- 1 x Set of Note Stickers
- 1 x USB-C Cable
- 1 x Power Adapter
Setup
- Unfolding the Keyboard: Carefully unfold the keyboard until it locks into its full 88-key position. Ensure the hinge mechanism is securely engaged.
- Power Connection: Connect the provided USB-C cable to the keyboard's power port and the power adapter. Plug the adapter into a standard electrical outlet. The keyboard can also operate on its internal battery for up to 10 hours on a full charge.
- Attaching the Music Stand: Insert the music stand into the designated slots on the top panel of the keyboard.
- Applying Note Stickers: For beginners, apply the included note stickers to the white keys as guided by the sticker sheet to assist with learning.
- Connecting Accessories: If desired, plug the microphone into the microphone input port. An optional sustain pedal (not included) can be connected to the sustain pedal port for enhanced playability.

This image displays the various input and output ports on the MOSEN MS081 keyboard, including the USB Type-C power input, microphone jack, and sustain pedal input, allowing for versatile connectivity.
Operating Instructions
Basic Operation
- Power On/Off: Press the 'POWER' button to turn the keyboard on or off.
- Volume Control: Use the 'VOLUME' buttons to adjust the overall sound level.
- Tone Selection: Press the 'TONE' button and use the number keys to select from 190 realistic tones.
- Rhythm Selection: Press the 'RHYTHM' button and use the number keys to select from 191 dynamic rhythms.
- Demo Songs: Press 'DEMO ONE' to play a single demo song or 'DEMO ALL' to cycle through all 80 built-in demo songs.
Advanced Features
- Auto-Chord: Activate the 'CHORD' function for automatic chord accompaniment.
- Split Function: Use the 'SPLIT' feature to divide the keyboard into two sections, allowing different tones to be played on each half.
- Record/Play: The 'RECORD' and 'PLAY' buttons allow you to record and playback your performances.
- Transpose: Adjust the pitch of the keyboard using the 'TRANSPOSE' function.
- Sustain: Press the 'SUSTAIN' button to apply a sustain effect to the notes. An external sustain pedal can also be used.
- Metronome: Activate the 'METRONOME' for timing assistance during practice.
Learning Tools
- Dual Keyboard Mode: Enables two players to use the keyboard simultaneously, ideal for teaching.
- Interactive Teaching Functions: Utilize the 'LESSON' mode for guided learning exercises.

This image provides a clear view of the keyboard's control panel, highlighting buttons for various functions such as tone, rhythm, demo songs, recording, and learning modes.

This image illustrates the keyboard's long-lasting battery, capable of providing up to 10 hours of playtime, making it suitable for portable use without constant power connection.
Portability and Folding
The MOSEN MS081 is designed for maximum portability. It weighs approximately 10.98 pounds and folds to a compact length of 25.2 inches, allowing for easy storage and transport.
- Folding Mechanism: Locate the folding button/latch (refer to Figure 5) and press it to release the hinge. Carefully fold the keyboard in half.
- Storage: Once folded, the keyboard can be stored in small spaces or carried in a compatible bag.

This image shows the MOSEN MS081 keyboard in a partially folded state, highlighting its sleek and portable design that allows it to be easily compacted for transport or storage.

This image provides a detailed view of the single-button folding mechanism, illustrating how to easily fold and unfold the keyboard for convenience.
Maintenance
- Cleaning: Use a soft, dry cloth to wipe the surface of the keyboard. Avoid using abrasive cleaners or solvents.
- Storage: When not in use, store the keyboard in a cool, dry place away from direct sunlight and extreme temperatures.
- Battery Care: For optimal battery life, avoid fully discharging the battery frequently. Charge the keyboard regularly, especially if it will be stored for extended periods.
Troubleshooting
- No Sound:
- Check the volume level.
- Ensure headphones are not plugged in if you intend to use the built-in speakers.
- Verify the power connection and battery charge.
- Keyboard Not Powering On:
- Confirm the power adapter is correctly connected and the outlet is functional.
- Charge the internal battery if it is depleted.
- Keys Not Responding:
- Restart the keyboard.
- Ensure no foreign objects are lodged between the keys.
Specifications
| Model Number | MS081 (also referred to as MDP-550) |
| Number of Keys | 88 |
| Key Type | Semi-Weighted |
| Tones | 190 |
| Rhythms | 191 |
| Demo Songs | 80 |
| Special Feature | Foldable |
| Power Source | Corded Electric, Internal Battery (up to 10 hours) |
| Connector Type | USB Type C |
| Item Weight | 10.98 pounds |
| Package Dimensions | 28.5 x 12 x 6.5 inches |
| Material Type | Plastic |
| Color | Black |
Warranty and Support
For any issues encountered after receiving or during the use of your MOSEN MS081 keyboard, please contact MOSEN MUSIC customer service. Our support team is available to assist you with troubleshooting and warranty-related inquiries.
Please refer to your purchase documentation for specific warranty terms and contact information.