Fosi Audio TP-02 User Manual page 9

• Please make sure that your devices (iPad, computer, etc.) are
turned on and not set to the minimum volume. Please change the
device with other one and try it again if you can. If it still not work
then it is the problem of the amplifier.
• Please make sure that the cables from your devices are working
and properly connected. You can change the cables with new one
and see if it will work again. If not then it is the problem from the
amplifier.
5: Why does the sound crack or make a lot of electric
noise?
• When you put your hand on the volume knob or the amplifier case
it will make some buzzing sound, it's normal because the amplifier
case and the volume knob are made of aluminum. Once you move
your hand away from the amplifier, the buzzing sound will
disappear.
• Please make sure all the cables are completely pushed into the
devices, an incomplete connection will cause the cracking sound.
• Please unplug all of the signal input cables and then check
whether cracking noise disappears, if not the crack is from the
amplifier.
• If you didn't use the original factory standard power supply,
please replace the power supply with the original standard power
supply before testing. Many power supplies in the market have
large interference coefficients, which will cause a lot of sound.
6: Why is there an interference sound after connecting the
signal line?
• If you use unshielded signal lines, there will be interference
signals entering the power amplifier. If you don't like the sound,
you are advised to use the shielded signal lines or unplug the
signal lines.