1. Introduction
The Douk Audio G4 is a versatile mono integrated Class D amplifier designed for HiFi home and desktop audio systems. It offers powerful amplification with a compact and durable aluminum chassis. The G4 can function as either a full-frequency amplifier or a subwoofer amplifier, thanks to its convenient B/M mode switch. It supports both 3.5mm AUX and RCA inputs, ensuring compatibility with a wide range of audio devices.
Featuring a TPA3116D2 chip and two NE5532 op-amps, the G4 delivers up to 100W of output power, capable of driving passive 3-10 inch full-frequency speakers or 4-12 inch subwoofers without audible noise, even at high output levels. This amplifier is an excellent choice for upgrading a 2.0 channel audio system to a 2.1 setup, providing an immersive audio experience.
2. Safety Information
Please read and understand all safety instructions before operating this device. Keep this manual for future reference.
- Do not expose this device to rain, moisture, dripping, or splashing.
- Do not place objects filled with liquids, such as vases, on the device.
- Ensure proper ventilation. Do not block any ventilation openings.
- Use only attachments/accessories specified by the manufacturer.
- Unplug the device during lightning storms or when unused for long periods.
- Refer all servicing to qualified service personnel.
- Use only the specified power supply (DC 12-24V).
3. Package Contents
Carefully unpack your Douk Audio G4 amplifier and check that all items are included:
- 1x Douk Audio G4 Mono Amplifier
- 1x 19V Power Supply (Optional, depending on purchase variant)
- 1x Instruction Manual
4. Product Overview
The Douk Audio G4 is a compact yet powerful digital amplifier. Below are diagrams highlighting its key components and features.
4.1 Front Panel Controls
- Power Indicator: Illuminates when the amplifier is powered on.
- Power Switch / Volume Knob: Turns the amplifier on/off and adjusts the output volume.
4.2 Rear Panel Connections
- AUX Input: 3.5mm stereo audio input.
- RCA Input: Stereo L/R RCA audio input.
- B/M Switch: Selects between Subwoofer (B) mode and Full-Frequency (M) mode.
- Speaker Output: Banana speaker jacks for connecting passive speakers or subwoofers.
- DC 12-24V Input: Power input jack.
4.3 Internal Components
The G4 utilizes a TPA3116D2 chip for efficient power amplification and two NE5532 op-amps for signal analysis and frequency processing. This combination ensures pure low-frequency filtering and efficient power consumption.
5. Setup Instructions
Follow these steps to set up your Douk Audio G4 amplifier:
5.1 Connecting Audio Sources
- Choose your input: Connect your audio source (e.g., DAC, Preamp, Phone, MP3 player, TV/Blu-ray, PC/Mac/Computer) to either the 3.5mm AUX input or the RCA input on the rear panel of the G4.
- Ensure the cables are securely connected.
5.2 Connecting Speakers/Subwoofers
- Identify your speaker type: The G4 can drive passive full-frequency speakers (3-10 inch / 10-200W) or passive subwoofers (4-12 inch / 40-200W).
- Connect speaker wires: Use banana plugs or bare wire to connect your speaker(s) to the banana speaker jacks on the rear panel. Ensure correct polarity (+ to + and - to -).
5.3 Selecting Operating Mode (B/M Switch)
- 'B' (Subwoofer Mode): Use this mode when connecting a subwoofer. The amplifier will output frequencies within the 20-200Hz range.
- 'M' (Full-Frequency Mode): Use this mode when connecting a full-range speaker. The amplifier will output frequencies within the 20-20KHz range.
5.4 Power Connection
- Connect the DC 12-24V power adapter (if included or purchased separately) to the DC input jack on the rear panel.
- Plug the power adapter into a suitable wall outlet.
5.5 Building a Stereo Audio System
The Douk Audio G4 is a mono amplifier. To achieve stereo sound (2.0 or 2.1 channel), you will need multiple G4 units:
- For 2.0 Channel Stereo: Use two G4 amplifiers. Set both to 'M' (Full-Frequency) mode. Connect one G4 to the left channel of your audio source and a passive speaker. Connect the second G4 to the right channel of your audio source and another passive speaker. This allows independent driving of left and right channels, avoiding mutual interference.
- For 2.1 Channel Stereo: Use three G4 amplifiers. Set two G4s to 'M' (Full-Frequency) mode for the left and right passive speakers. Set the third G4 to 'B' (Subwoofer) mode for a passive subwoofer. Alternatively, you can use one G4 in 'B' mode for a subwoofer, combined with a separate 2.0 channel amplifier for your main speakers, or a device with a dedicated low-frequency output.
6. Operating Instructions
- Power On: Rotate the Power Switch / Volume Knob clockwise until you hear a click and the Power Indicator light turns on.
- Adjust Volume: Continue rotating the Power Switch / Volume Knob clockwise to increase the volume, and counter-clockwise to decrease it.
- Select Mode: Ensure the B/M switch on the rear panel is set to the appropriate mode ('B' for subwoofer, 'M' for full-frequency) for your connected speaker(s).
- Play Audio: Start playing audio from your connected source.
- Power Off: Rotate the Power Switch / Volume Knob counter-clockwise until you hear a click and the Power Indicator light turns off.
7. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the amplifier. Do not use liquid cleaners or aerosols.
- Ventilation: Ensure the amplifier has adequate airflow around it. Do not cover ventilation openings.
- Storage: When not in use for extended periods, store the amplifier in a cool, dry place away from direct sunlight and extreme temperatures.
- Cable Management: Keep audio and power cables organized and free from kinks or excessive bending to prevent damage.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Power adapter not connected or faulty; power outlet not working. | Check power connections. Ensure the power adapter is functioning and the outlet has power. Confirm the power switch is turned on. |
| No sound output | Incorrect input/output connections; volume too low; wrong mode selected (B/M switch); faulty audio source/speakers. | Verify all audio cables are correctly connected. Increase volume. Check the B/M switch setting. Test with a different audio source or speakers. |
| Distorted sound | Volume too high; impedance mismatch; faulty cables; audio source distortion. | Reduce volume. Ensure speaker impedance is within 4-8Ω. Replace audio cables. Check if the audio source is producing clean sound. |
| Humming or buzzing noise | Ground loop issue; interference from other electronics; faulty cables. | Try plugging the amplifier into a different power outlet. Move the amplifier away from other electronic devices. Use shielded audio cables. |
9. Specifications
| Feature | Specification |
|---|---|
| Audio Input | 3.5mm AUX / RCA |
| Audio Output | Banana Speaker Jacks |
| Rated Power | 100W |
| Peak Power | 300W |
| THD | 0.001% |
| SNR | 103dB |
| Speaker Impedance | 4-8Ω |
| Matched Full-Frequency/Crossover Speaker | 3-10 inch / 10-200W |
| Matched Subwoofer Speaker | 4-12 inch / 40-200W |
| Frequency Range (Subwoofer Mode) | 20-200Hz |
| Frequency Range (Full-Frequency Mode) | 20-20KHz |
| Working Voltage | DC 12-24V (5.5mm (-) / 2.5mm (+)) |
| Dimensions (L*W*H) | 105*85*30mm / 4.13*3.35*1.18in |
| Net Weight | 240g / 0.53lb |
| Package Weight (with 19V4.74A power supply) | 445g / 0.98lb |
10. User Tips
- Power Supply: The 19V power supply is often optional. Please ensure you have a compatible DC 12-24V power supply with the correct barrel connector dimensions (5.5mm outer, 2.5mm inner, center positive) if it was not included with your purchase.
- Stereo Setup: Remember that the G4 is a mono amplifier. For a true stereo experience (2.0 or 2.1 channels), you will need to purchase and connect two or three G4 units, respectively, as illustrated in the setup section.
- Cable Quality: Using high-quality audio cables can significantly reduce noise and improve sound clarity.
11. Warranty and Support
Douk Audio products are designed for reliability and performance. For any technical support or warranty inquiries, please contact your retailer or the official Douk Audio support channels. Keep your purchase receipt as proof of purchase for warranty claims.
