ZK-301B 30W TWS Bluetooth Amplifier Audio Module
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6>.The audio input and power supply voltage/current must both be sufficient to ensure enough power
output.
7>.The higher the power supply voltage, the greater the output power.
8>.The smaller the impedance of the speaker, the greater the output power. It is recommended to use
4ohm speakers.
9>.Please read the user manual and product description carefully before use.
7.Frequently Asked Questions:
1>.How to choose a power supply adapter?
The power supply for the module is very important and must be used with caution. The ripple of the
selected power supply should be kept to a minimum as a large ripple will cause the background noise
of the power amplifier board to increase and a current sound will be produced.
A power adapter with a 5.5*2.1mm or 5.5*2.5mm plug is required, and it is recommended to use a
24V power supply with a current of more than 3A. The higher the voltage and current, the better the
output power. For power voltages lower than 12V, it is best to connect a 4ohm speaker. If an 8ohm
speaker is used, 24V voltage is recommended.
Input voltages higher than 25V may damage the module. Low voltage inputs will distort the sound
after amplification and low currents will not be able to drive the speaker properly or will pull the voltage
down, resulting in abnormal operation or poor sound quality. If a low powered adapter such as a 9V 2A
adapter is used, it is advised to adjust the volume to the maximum as this may cause distortion and
affect the sound quality.
2>.How to choose a speaker?
Commonly used speakers usually have an impedance of 4ohm to 8ohm and do not require
distinguishing between positive and negative polarity.
The module can also work properly with low powered speakers with a power range of 5W to 15W,
however, it must be connected to a low powered adapter such as one with a voltage lower than 12V to
avoid damaging the speaker.
There is no need to worry about the speaker burning out when connecting to speakers with a power
of 30W to 40W. The module can be connected to a 12V to 24V power supply, with the higher voltage
providing more output sound or power. The speaker's power must not exceed 40W as this will affect
the sound quality.
3>.How to choose Bluetooth or AUX audio input mode?
AUX/USB mode takes priority over Bluetooth mode. If you wish to use Bluetooth as your input
audio signal, you must first disconnect the AUX or USB. AUX and USB connections take precedence.
4>.Why is the volume normally when small and there is turbidity after increase volume?
If there is sound distortion, try changing the adapter power supply to one with a higher voltage and
current or turn down the volume.
5>.Why is the volume normally when volume small and there is pause after increase volume?
The input power is insufficient. Try using an adapter power supply with higher voltage and current.
The power supply has an intermittent power-off protection feature. Use a power adapter that
matches the requirements.
If the power of the power supply is too high, reduce the power of the input power.
If the power amplifier board is too hot, triggering the overheat protection, increase size of radiator.
6>.What factors are related to the sound quality?
The sound quality is not just determined by the power amplifier module, but also by the power
supply, sound source and the entire sound system. Every component of the sound system affects the
