User Guide

Fosi Audio Class D Amplifier Troubleshooting Tips.
FAQ.
1. How to contact us?
Please contact us via email at [e-mail] or [e-mail];
2. What type of speakers work best with the Fosi Audio amplifiers?
Fosi Audio Amplifiers work great with any 4, 6 or 8 ohm passive speakers. (not fit for powered
speakers or powered subwoofer)
3. Can I connect a turntable to my amp, why is the volume is extremely low?
Some turntables may not have a built-in preamp and you would need to add an external phono
preamp to bring the instrument level signal of the turntable to line-level. Some turntables may
have a built-in preamp but have a switch on the back for either “line” or “phono,” such as
the Music Hall USB-1 or the Audio Technica AT-LP120; the switch would need to be selected to
“line” in order to work directly with the speakers.
4. How to connect the amplifier to audio system?
Step1:connect the amplifier to your speakers via banana plugs or bare wire.
Step2:connect the amplifier to power supply;
Step3:connect the power supply to AC outlet;
Step4:connect the amplifier to your audio source via RCA cable;
Step5:turn on this amplifier and volume up;
5. Can I connect a subwoofer to the Fosi Audio amps?
If you bought subwoofer amps from Fosi Auido or 2.1 Channel amplifier, (or the amp that with
sub output), you can connect to subwoofer, but if you got the 2.0 Channel amplifier, you can’t
connect to the subwoofer.
6. Can I take my amp to another country with a different voltage?
Fosi Audio amplifiers come with a power supply that accept AC110V-240V, it will automatically
convert to different voltage when plugged in. The power cable is also detachable which makes it
convenience to replace the AC plug with a different type if you don’t want to use an adapter plug.
7. Can I leave the Fosi Audio amps power on all the time?
Sure, the Fosi Audio amps have the power-saving idle mode that activates after you stop playing
music, and they are class d amplifier, will cost very low power when nothing playing though it.
8. Why sparks flying when I plug the power cord into the amp? And does it unsafe?
Some customers may see some slight sparks flying when they plug the power supply into the
amplifier, because they use it in wrong way, you need to connect the amp to the power supply
first, then plug the power supply into the 110v AC outlet, don't worry about the sparks, because
this is class d amplifier, the capacitors need to charge when the power in, it's normal and safe.