1.Description:

• ZK-502H is a HIFI high-power Stereo Bluetooth Audio module.
• Dual channels audio signal output.
• Built-in amplifier module therefore it can connect to loudspeaker directly.
• It is ideal for DIY wireless Bluetooth speakers and transponders.

2.Features:

• 4 audio input modes
• 5 working protection modes
• Dual channel stereo output
• Active/Passive audio output
• 50W high power
• Bluetooth automatic re-connection

3.Parameters:

• Product Number:ZK-502H
• Working Voltage:DC 9.0V~24V
• Amplifier IC:TPA3116D2
• Audio input type:Bluetooth/AUX/U-disk/PC USB sound card
• Bluetooth version:BLE 5.0
• Communication distance:15meter(Max)
• Channel:Dual channel stereo output
• Output impedance:4ohm~8ohm
• Match speaker:10W~100W
• Audio output:Active/Passive audio output
• Output Power:
• Output power 12W+12W at 12V 8ohm
• Output power 20W+20W at 12V 4ohm
• Output power 18W+18W at 15V 8ohm
• Output power 30W+30W at 15V 4ohm
• Output power 32W+32W at 19V 8ohm
• Output power 40W+40W at 19V 4ohm
• Output power 38W+38W at 24V 8ohm
• Output power 50W+50W at 24V 4ohm
• Overvoltage protection:Yes
• Undervoltage protection:Yes
• Over temperature protection:Yes
• Short circuit protection:Yes
• Working Temperature range:-40℃~85℃
• Working Humidity Range:5%-95%RH
• Module Size:60x60x29mm

4.Use steps:

• Choose the right speaker and connect as shown in wiring diagram.
• Connect to right power supply from input terminal.LED indicator will flashing and it means that module enters pairing mode.And then speak prompt voice and it means that module is waiting for pairing.
• Turn ON Bluetooth in phone.
• Select Bluetooth device ‘Wuzhi Audio’ in your Bluetooth device listing.
• LED indicator will keep ON and it means that module is successfully connected and is waiting for playing.
• Module will playing music after select music in phone. LED indicator will keep slowly blinking.
• Increase or Decrease volume by adjust potentiometer.
• Module will speak prompt voice if disconnected.

5.Application:

• Modified speaker
• Amplifier equipment
• Car Bluetooth device

6.Note:

• The power amplifier board should be as far away as possible from the WIFI signal (router) avoid signal interference.
• Recommended power supply voltage DC 9~24V.Module will be damaged if input voltage is more than 24V.
• Please don’t use too long wires to avoid signal interference.
• The format of U-disk must be FAT32 and the maximum memory is 32G.
• It can only select one audio output mode between active output and passive audio output.
• Please read use manual and description before use.

7.Frequently Asked Questions:

• Q1.How to choose a power supply adapter?
• A: The power supply of the module is very critical. The user must pay enough attention to the power supply. Otherwise it may not work properly.
• The higher the voltage and the higher the current then the better the output power. It is better to connect 3~4in speaker if user only have 12V 1A power adapter. It is no problem to connect 8~10in speaker if user have a power adapter which more than 19V 5A.
• The sound will be distorted after increase volume if the voltage is too low.
• If the current is too small, the speaker cannot be driven to work, and the speaker will pull the voltage low, resulting in abnormal operation or poor sound quality.
• It is recommended to use 18V/19V/24V power supply with current more than 3A.

• Adjust the volume to the maximum may be distorted and affecting the sound quality if input low power adapter such as 9V/12V 1A/2A adapter.

• Q2.How to choose a speaker?

• A:Commonly used speakers are generally 4ohm~8ohm.The speaker no need distinguish between positive and negative polarity.
• It can also work properly if the speaker has low power such as 10W~30W. But it needs connect to low power adapter such as less than 15V to prevent damage to the speaker.

• User don't have to worry about the problem of the speaker damaged if connect to 50W~100W speaker.Module can connect 12V~24V.The higher the voltage selected, the greater the sound or power that can be output.

• Q3.How to choose audio input mode?

• A: Audio connected first has high priority between U-disk and AUX. Bluetooth audio has the lowest priority.User need disconnect U-disk or AUX if use Bluetooth as input video signal.

• Q4.Why is the volume working normally when volume small, and there is turbidity after increase volume?

• A: Sound distortion.Please change the adapter power supply with higher voltage level.

• Q5.Why is the volume working normally when volume small, and there is pause after increase volume?

• A: The input power is insufficient.Please change the adapter power supply with higher voltage level.
• Power supply itself intermittent power-off protection.Please change a match power adapter.
• The power of the power supply is too large so please reduce the power of the input power.
• The power amplifier board is seriously heated resulting in trigger overheat protection.So please increase the radiator.

8.Package:

• 1pcs ZK-502H HIFI 50W*2 Bluetooth Amplifier Module
• 1pcs heat sink with adhesive
• 1pcs 6mm knob cap
• 1pcs DC-005 power adapter
• 1pcs Self locking button cap
• 2pcs shell
• 4pcs M2*12mm Copper column
• 8pcs M2*8mm screw
• 1pcs screwdriver