1. Introduction
Thank you for purchasing the SUNBUCK AV-338ST HIFI Digital Stereo Audio Power Amplifier. This manual provides detailed instructions for the safe and efficient operation of your new amplifier. Please read this manual thoroughly before use and retain it for future reference.
The AV-338ST is a versatile 5-channel audio amplifier designed for home entertainment, offering HIFI stereo sound, microphone inputs for karaoke, Bluetooth 5.0 connectivity, FM radio, and support for USB/SD media playback.
2. Important Safety Instructions
- Read these instructions carefully before operating the unit.
- Keep this manual for future reference.
- Heed all warnings on the product and in the operating instructions.
- Follow all instructions.
- Do not use this apparatus near water.
- Clean only with a dry cloth.
- Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
- Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
- Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
- Only use attachments/accessories specified by the manufacturer.
- Unplug this apparatus during lightning storms or when unused for long periods of time.
- Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
3. Package Contents
Please check that all items listed below are included in your package:
- 1 x SUNBUCK AV-338ST Audio Power Amplifier
- 1 x User Manual
- 1 x Remote Control
4. Product Overview
4.1 Front Panel Controls and Indicators
- Power Button: Turns the amplifier on/off.
- Echo Control: Adjusts the echo effect for microphones.
- Mic Vol (Microphone Volume): Adjusts the volume of the connected microphones.
- Master Vol (Master Volume): Controls the overall output volume of the amplifier.
- Mic 1 / Mic 2 Inputs: 6.35mm jack inputs for connecting microphones.
- Bass Control: Adjusts the low-frequency audio output.
- Treble Control: Adjusts the high-frequency audio output.
- LED Display: Shows current mode, track information, or FM frequency.
- Audio Input Selector: Switches between USB, BT (Bluetooth), FM, CD, and DVD inputs.
- USB Port: For connecting USB flash drives for media playback.
- SD/MMC Slot: For inserting SD/MMC cards for media playback.
- BT Button: Activates Bluetooth pairing mode.
4.2 Rear Panel Connections
- CD Input (RCA): For connecting CD players or other stereo audio sources.
- DVD Input (RCA): For connecting DVD players or other stereo audio sources.
- AUX Input (RCA): For connecting auxiliary audio devices.
- LINE Output (RCA): Signal output for connecting to an active subwoofer or other equipment.
- Speaker System (4-16Ω): Terminals for connecting passive speakers. Supports 5-channel output (Front L/R, Center, Surround L/R).
- FM ANT: Connector for the FM antenna.
- Power Input: AC power cord connection (110V/220V 50/60Hz).
4.3 Internal Components (Diagram)
The internal design features a toroidal transformer for efficient power delivery, filter capacitors for stable power, and speaker protection circuitry to safeguard your speakers.
5. Setup Guide
Follow these steps to set up your SUNBUCK AV-338ST amplifier:
- Speaker Connection:
- Connect your passive speakers to the "SPEAKER SYSTEM 4-16Ω" terminals on the rear panel. Ensure correct polarity (+ to + and - to -) for each speaker.
- For 5-channel output, connect front left (L), front right (R), center (C), surround left (SL), and surround right (SR) speakers.
- The amplifier supports speakers with an impedance of 4 to 16 ohms.
Image: Detailed view of speaker and audio input connections on the rear panel. - Audio Source Connection:
- Connect your CD player to the "CD INPUT" RCA jacks.
- Connect your DVD player to the "DVD INPUT" RCA jacks.
- Connect other auxiliary audio devices (e.g., TV, media player) to the "AUX INPUT" RCA jacks.
- If using an active subwoofer, connect its input to the "LINE OUTPUT" RCA jacks.
- Microphone Connection:
- Plug your microphones into the "MIC1" and "MIC2" 6.35mm jacks on the front panel.
Image: Amplifier with two microphones connected to the front panel inputs. - FM Antenna Connection:
- Connect the provided FM antenna to the "FM ANT" terminal on the rear panel for improved radio reception.
- Power Connection:
- Ensure the amplifier's power switch is in the OFF position.
- Connect the power cord to the "Power Input" on the rear panel and then to a suitable wall outlet (110V/220V 50/60Hz).
6. Operating Instructions
- Power On/Off: Press the "Power" button on the front panel to turn the amplifier on or off. The LED display will illuminate when powered on.
- Input Selection: Use the "INPUT" selector switch on the front panel to choose your desired audio source (USB, BT, FM, CD, DVD).
- Volume Control: Rotate the "MASTER VOL" knob to adjust the overall sound volume. Use the "BASS" and "TREBLE" knobs to fine-tune the low and high frequencies.
- Microphone Usage (Karaoke):
- Connect microphones to MIC1 or MIC2 inputs.
- Adjust microphone volume using the "MIC VOL" knob.
- Adjust the echo effect for vocals using the "ECHO" knob.
- Bluetooth Connectivity:
- Select "BT" as the input source using the "INPUT" selector or press the "BT" button. The LED display will show "BLUE" or "BT".
- On your mobile device, enable Bluetooth and search for available devices.
- Select "BT" (or similar name) from the list to pair. Once paired, you can stream audio from your device to the amplifier.
Video: Demonstration of unboxing, amplifier features, and Bluetooth pairing with a mobile device. - FM Radio:
- Select "FM" as the input source.
- Use the control buttons (usually CH+/CH- or Mode) to scan for and select radio stations.
- USB/SD Media Playback:
- Insert a USB flash drive into the "USB" port or an SD/MMC card into the "SD/MMC" slot.
- Select "USB" or "SD" as the input source. The amplifier will automatically detect and play compatible audio files.
- Use the playback control buttons (Play/Pause, Next, Previous) on the front panel or remote control.
- Remote Control: The included remote control allows for convenient operation of various functions from a distance, including power, input selection, volume, and media playback controls.
7. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the amplifier. Do not use liquid cleaners or aerosol sprays.
- Ventilation: Ensure that the ventilation openings on the top and sides of the amplifier are not blocked to prevent overheating.
- Storage: If storing the amplifier for an extended period, unplug it from the power outlet and store it in a cool, dry place.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Power cord not connected; Power outlet faulty; Amplifier power switch off. | Check power cord connection; Test power outlet; Press the power button on the front panel. |
| No sound output | Incorrect input selected; Volume too low; Speakers not connected or faulty; Audio source not playing. | Select the correct input source; Increase Master Volume; Check speaker connections and ensure they are working; Verify audio source is playing. |
| Bluetooth not pairing | Amplifier not in Bluetooth mode; Device Bluetooth off; Device too far. | Ensure amplifier is in "BT" mode; Turn on Bluetooth on your device; Keep device within range (approx. 10 meters); Try re-pairing. |
| Microphone not working | Microphone not connected properly; Mic Vol too low; Microphone faulty. | Ensure microphone is fully plugged into MIC1/MIC2; Increase "MIC VOL"; Test with another microphone. |
| Poor FM reception | FM antenna not connected or poorly positioned. | Connect the FM antenna; Adjust antenna position for better signal. |
9. Specifications
| Feature | Specification |
|---|---|
| Model | AV-338ST |
| Channels | 5 (4.1) |
| Rated Voltage | 110V/220V 50/60Hz |
| Peak Power | 2000W |
| Maximum Power Per Channel | 60 W |
| Rated Frequency | 20Hz - 20KHz |
| Signal to Noise Ratio | 90dB |
| Standard Impedance | 4 to 16 ohm |
| Total Harmonic Distortion | ≤ 0.5% |
| Signal Input Sensitivity | 200mv (± 30mv) |
| Microphone Input Sensitivity | 9 mv (± 2mv) |
| Recording Level Output | 1V |
| Auxiliary Level Output | 1V |
| DC12V Support | No |
| Media Support | USB Disk (Max 64GB), SD Card (Max 64GB) |
| Dimensions (L x W x H) | 25 x 21.5 x 6 cm / 9.8 x 8.5 x 2.4 inches |
| Color Options | Black, Gold |
10. User Tips
- Bluetooth Pairing: Some users find it helpful to ensure no other devices are actively trying to connect to the amplifier's Bluetooth to ensure a smooth pairing process. If you experience issues, try turning off Bluetooth on nearby unused devices.
- Microphone Echo: Experiment with the "ECHO" control to find the optimal reverberation level for your voice or music, enhancing the karaoke experience.
- Power On: The amplifier powers on via its dedicated power button. It does not automatically power on when an audio signal is detected.
11. Warranty and Support
This product is covered by a standard manufacturer's warranty against defects in materials and workmanship. Please refer to your purchase documentation for specific warranty terms and duration.
For technical support, troubleshooting assistance, or warranty claims, please contact your retailer or the manufacturer's customer service department. Keep your proof of purchase readily available.
