Introduction
The EC Buying ZK-502H is a high-fidelity 2.0 stereo digital power amplifier module designed to deliver clear and powerful audio. Featuring the TPA3116D2 chip, this amplifier board provides 50W+50W output and supports multiple audio input sources including Bluetooth 5.0, AUX, and USB. It is equipped with various protection mechanisms to ensure stable and secure performance.
Product Features
- High-Fidelity Audio: Delivers 50W+50W output with the TPA3116D2 chip for crystal-clear stereo sound.
- Multiple Input Sources: Supports Bluetooth 5.0, AUX (3.5mm jack), USB flash drive, and computer USB sound card (plug and play).
- Bluetooth 5.0 Connectivity: Offers seamless wireless connection with a range of over 15 meters in unobstructed environments.
- Robust Protection: Includes overvoltage, undervoltage, overheating, DC detection, and short circuit protection for enhanced safety and durability.
- Wide Speaker Compatibility: Adaptable to 10-100W, 4-8Ω speakers.
- Flexible Power Supply: Operates with a DC power supply ranging from 9V to 24V.
- Compact Design: Measures 60x60x29mm, making it suitable for various applications and portable setups.
Package Contents
Please verify that all components are present in your package:
- ZK-502H Amplifier Board
- Top and Bottom Acrylic Plates
- Volume Knob
- Heat Sink
- Screwdriver
- Mounting Hardware (screws, standoffs)
- DC Power Adapter Cable
Image: All components included with the ZK-502H amplifier board, laid out for assembly.
Setup Instructions
1. Assembly (Optional, if not pre-assembled)
- Attach the heat sink to the main chip on the amplifier board.
- Secure the amplifier board between the two acrylic plates using the provided standoffs and screws.
- Install the volume knob onto the potentiometer shaft.
2. Power Connection
- Ensure the amplifier is switched off and the volume knob is set to minimum.
- Connect a DC power supply (9-24V) to the DC IN port (labeled DC9-24V). Use the provided DC power adapter cable if necessary.
- Important: Using a higher voltage within the specified range (e.g., 24V) is recommended for achieving higher power output.
3. Speaker Connection
- Connect your passive speakers to the speaker output terminals (labeled L+, L-, R+, R-).
- Ensure correct polarity: positive (+) to positive, negative (-) to negative for each channel.
- The amplifier supports speakers with an impedance of 4-8Ω and power rating of 10-100W.
4. Audio Input Connection
Choose one of the following audio input methods:
- Bluetooth: No physical connection needed. Proceed to Operating Instructions for pairing.
- AUX: Connect an audio source (e.g., smartphone, MP3 player) to the 3.5mm AUX IN jack using an audio cable.
- USB: Insert a USB flash drive into the USB IN port or connect the amplifier to a computer via USB for use as a sound card.
Image: Top view of the ZK-502H amplifier board, highlighting the AUX IN, Bluetooth, USB IN, DC IN, and speaker output terminals.
Operating Instructions
1. Power On/Off
- Press the ON/OFF button to power on the amplifier. A blue indicator light will illuminate.
- Press the ON/OFF button again to power off the amplifier.
2. Volume Control
- Rotate the large silver knob clockwise to increase volume.
- Rotate the large silver knob counter-clockwise to decrease volume.
3. Input Mode Selection
The amplifier automatically detects the input source. If multiple sources are connected, it will prioritize them or switch based on activity.
- Bluetooth Mode: When powered on, the amplifier will enter Bluetooth pairing mode. A voice prompt will confirm "Bluetooth Mode".
- AUX Mode: If an AUX cable is connected and playing audio, the amplifier will switch to AUX input.
- USB Mode: If a USB flash drive is inserted or connected to a computer, the amplifier will switch to USB input.
4. Bluetooth Pairing
- Ensure the amplifier is powered on and in Bluetooth mode (indicated by a voice prompt).
- On your audio device (e.g., smartphone, tablet), enable Bluetooth and search for available devices.
- Select "ZK-502H" from the list of devices to pair.
- Once paired, a voice prompt will confirm the connection. You can now play audio from your device.
Specifications
| Product Model | ZK-502H |
| Chip Solution | TPA3116D2 (with AM interference suppression) |
| Audio Input | Bluetooth 5.0, AUX (3.5mm), USB Flash Drive, Computer USB Sound Card |
| Power Supply | DC 9-24V |
| Output Power (Max) | 50W + 50W (at 24V, 4Ω) |
| Speaker Impedance | 4-8Ω |
| Speaker Power | 10-100W |
| Number of Channels | 2.0 Stereo (Left and Right) |
| Bluetooth Version | 5.0 |
| Bluetooth Range | >15 meters (unobstructed) |
| Protection Mechanisms | Overvoltage, Undervoltage, Overheating, DC Detection, Short Circuit Protection |
| Product Dimensions | 60 x 60 x 29mm |
| Product Weight | Approximately 104g (including packaging) |
Power Output Table:
| Power Supply Voltage | 8Ω Speaker Output | 4Ω Speaker Output |
|---|---|---|
| 12V | 12W + 12W | 20W + 20W |
| 15V | 18W + 18W | 30W + 30W |
| 19V | 32W + 32W | 40W + 40W |
| 24V | 38W + 38W | 50W + 50W |
Maintenance
- Keep the amplifier board clean and free from dust. Use a soft, dry cloth for cleaning.
- Avoid exposing the device to moisture, extreme temperatures, or direct sunlight.
- Ensure proper ventilation to prevent overheating, especially during prolonged use at high volumes.
- Do not attempt to disassemble or modify the amplifier beyond the initial assembly steps, as this may void any potential warranty and could cause damage.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output. |
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| Bluetooth device cannot pair. |
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| Distorted sound. |
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Warranty and Support
For product support, technical assistance, or warranty inquiries, please contact EC Buying customer service through the retailer where the product was purchased. Please retain your proof of purchase for any warranty claims.
Manufacturer: EC Buying
Model: ZK-502H