1. Introduction
The Nobsound MS-10D MKIII is a versatile HiFi Bluetooth Hybrid Tube Power Amplifier designed to deliver rich, warm audio. This upgraded version features expanded connectivity options including Coaxial and Optical inputs, alongside traditional RCA, USB, and Bluetooth. It also includes an active subwoofer output for enhanced bass performance. The amplifier's circuit design has been refined to minimize background noise and provide a purer sound experience.
Utilizing 6P1 and 6N1 vacuum tubes, the MS-10D MKIII offers a clear, smooth, and delicate sound profile, characteristic of tube amplification. Its elegant design, featuring a black lacquered panel and visible vacuum tubes, makes it a stylish addition to any home audio or desktop setup.
Figure 1.1: Nobsound MS-10D MKIII Hybrid Tube Power Amplifier.
2. What's in the Box
Upon unpacking your Nobsound MS-10D MKIII, please ensure all components are present and in good condition. The package should contain:
- 1 x Nobsound MS-10D MKIII Tube Amplifier
- Power Cable
- User Manual (this document)
Figure 2.1: Packaging contents and dimensions of the Nobsound MS-10D MKIII.
3. Product Overview
3.1 Front Panel
Figure 3.1: Front Panel Controls.
- Power Button: Toggles the amplifier on and off.
- USB Port: For playing lossless music formats (WMA/WNV/MP3/FLAC) from a USB drive.
- Headphone Jack: 3.5mm output for connecting headphones.
- Play/Pause/Previous/Next Controls: Buttons for media playback control when using USB or Bluetooth input.
- Treble Control: Adjusts the high-frequency response of the audio.
- Bass Control: Adjusts the low-frequency response of the audio.
- VU Meter: Visual indicator of audio output level.
- Input Selector: Rotary switch to select between CD/DVD (RCA), BT/USB, and Optical/Coaxial inputs.
- Volume Control: Adjusts the overall output volume.
- BT.LED: Bluetooth indicator light.
3.2 Rear Panel
Figure 3.2: Rear Panel Connections.
- Audio Input (RCA): Connect audio sources like CD/DVD players, TVs, or other devices via RCA cables.
- Bass Output (Subwoofer): Connect an active subwoofer to enhance bass sound effects.
- Coaxial Input: Digital audio input for compatible devices.
- Optical Input: Digital audio input for compatible devices.
- Speaker Outputs (Banana/Binding Posts): Connect passive speakers (4-16Ω impedance).
- AC Input: Power connection for the amplifier.
- Fuse: Replaceable fuse for circuit protection.
4. Setup
Follow these steps to set up your Nobsound MS-10D MKIII amplifier:
- Unpack the Amplifier: Carefully remove the amplifier and all accessories from the packaging.
- Tube Installation: The vacuum tubes are pre-installed but ensure they are securely seated in their sockets. Handle tubes by their base to avoid damage.
- Connect Speakers: Connect your passive speakers to the Speaker Outputs on the rear panel using appropriate speaker cables. Ensure correct polarity (+ to + and - to -). The amplifier supports speakers with 4-16Ω impedance.
- Connect Subwoofer (Optional): If using an active subwoofer, connect it to the Bass Output on the rear panel.
- Connect Audio Sources:
- For analog devices (e.g., CD/DVD player, turntable with pre-amp), use RCA cables to connect to the Audio Input.
- For digital devices, use Optical or Coaxial cables to connect to the respective inputs.
- For USB playback, insert a USB drive into the front panel USB port.
- Connect Power: Plug the power cable into the AC Input on the rear panel, then plug the other end into a suitable power outlet.
Figure 4.1: Connection Diagram.
5. Operating Instructions
- Power On: Press the Power button on the front panel to turn on the amplifier. The tubes will begin to glow.
- Select Input: Use the Input Selector knob to choose your desired audio source (CD/DVD, BT/USB, Optical/Coaxial).
- Adjust Volume: Rotate the Volume control knob to set the desired listening level. Start at a low volume and gradually increase.
- Tone Control: Use the Treble and Bass knobs to fine-tune the audio to your preference.
- Bluetooth Pairing:
- Select "BT/USB" input. The BT.LED will blink, indicating pairing mode.
- On your device (smartphone, tablet, etc.), enable Bluetooth and search for "Nobsound MS-10D MKIII".
- Select the amplifier to pair. Once connected, the BT.LED will remain solid.
- Use the Play/Pause/Previous/Next buttons on the amplifier or your device to control playback.
- USB Playback:
- Insert a USB drive containing supported audio files (WMA/WNV/MP3/FLAC) into the front USB port.
- Select "BT/USB" input. The amplifier will automatically detect and begin playing music from the USB drive.
- Use the Play/Pause/Previous/Next buttons to navigate tracks.
- Headphone Use: Plug your headphones into the 3.5mm Headphone Jack. Audio will automatically switch from speakers to headphones.
Video 5.1: Official Nobsound demonstration of the MS-10D MKIII Bluetooth Tube Amp in operation. This video showcases the amplifier's aesthetic and basic functionality, including the glowing tubes and VU meter movement during audio playback.
6. Maintenance
- Cleaning: Use a soft, dry cloth to clean the amplifier's exterior. Avoid using liquid cleaners or abrasive materials.
- Ventilation: Ensure adequate ventilation around the amplifier. Do not block the ventilation holes or place the unit in an enclosed space, as proper airflow is crucial for tube longevity and performance.
- Tube Care: Vacuum tubes generate heat and have a finite lifespan. While durable, avoid touching them when hot. If a tube needs replacement, ensure the amplifier is powered off and unplugged before handling. Refer to Nobsound's official resources for compatible replacement tubes.
- Storage: If storing the amplifier for an extended period, disconnect it from power and store it in a cool, dry place away from direct sunlight and extreme temperatures.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Power cable disconnected; Power outlet faulty; Blown fuse. | Check power cable connection. Try a different outlet. Inspect and replace fuse if necessary (refer to fuse specifications). |
| No sound output | Incorrect input selected; Speaker cables loose/incorrectly connected; Volume too low; Muted source device. | Verify input selection. Check all speaker connections and polarity. Increase volume. Ensure source device is not muted. |
| Distorted sound | Volume too high; Incorrect impedance speakers; Faulty audio cable; Damaged tubes. | Reduce volume. Ensure speakers match impedance requirements (4-16Ω). Replace audio cables. Inspect tubes for damage or consult Nobsound support. |
| Bluetooth connection issues | Device not in pairing mode; Amplifier too far from device; Interference. | Ensure amplifier is on BT/USB input and BT.LED is blinking. Move device closer to amplifier. Reduce interference from other wireless devices. |
| Bluetooth always active (even on other inputs) | Designed behavior of the unit. | This is a known characteristic of the amplifier. To prevent unwanted connections, disable Bluetooth on your source device when not in use. |
| Crackling sound when turning off (Bluetooth mode) | Normal operational characteristic. | This is a minor audible artifact that may occur when powering down the unit while Bluetooth is active. It does not indicate a fault. |
| USB playback not working | Unsupported file format; USB drive not properly inserted; Corrupted files. | Ensure files are in supported formats (WMA/WNV/MP3/FLAC). Re-insert USB drive. Try a different USB drive or reformat the current one. |
8. Specifications
| Feature | Detail |
|---|---|
| Model Number | Ms-10d 110v |
| Product Dimensions | 1.26 x 1.06 x 0.63 inches |
| Item Weight | 10 pounds |
| Tube Models | 6P1 x 2, 6N1 x 2 |
| Audio Inputs | Bluetooth, USB, Coaxial, Optical, RCA (CD/DVD) |
| Audio Outputs | Banana speakers, Subwoofer, 3.5mm Headphone |
| Speaker Impedance | 4-16Ω |
| USB Support | Lossless music formats (WMA/WNV/MP3/FLAC) |
| Manufacturer | Nobsound |
| Country of Origin | China |
9. Warranty and Support
For warranty information, technical support, or service inquiries regarding your Nobsound MS-10D MKIII amplifier, please refer to the official Nobsound website or contact the seller directly. Keep your purchase receipt as proof of purchase.
Seller: Douk Audio Direct
For additional resources and product information, visit the Nobsound Store on Amazon.