I recently discovered Fosi Audio while looking for an amp to update my old music system. This is a short review regarding my experience with Fosi Audio BT20A Pro amp, which is an upgrade and a newer version of the BT20A. Music has been crucial and plays a big role in my life, from organizing to attending shows, collecting records and enjoying music 24/7. But don't expect any technical data on this review since I am not a professional nor a sound engineer, just a huge music lover and here is my humble opinion as an average user.
The first thing that you will notice when opening the package is how small and compact this little guy is, and how easy is to connect and play your favourite music. One of my top priorities when using new devices is the simplicity to set up, and this is the case with this amp. Just plug and play. The design is super minimalistic, pretty solid and seems to be of good quality with a blue finish on its aluminium case. The front panel has the power switch on the left, and 3 knobs (bass and treble tone controls and the volume knob) which seem to be very sturdy. On the back, you will find the RCA and speaker inputs, the bluetooth antenna, the DC power jack and a 3,5mm pre-out connection which means that you can connect an active subwoofer, active speakers, or even another amp. It also comes with the option to swap op-amp chips, and it supports many of them such as Sparkos SS3602, MUSES02, OPA2604AP, OPA2134PA, hence adding a lot of customization options. I have not tried this since I consider the sound to be more than good enough for my non professional ears but I think it is a very interesting feature for the enthusiastic audiophiles who like to test different choices and fine tune the sound of their equipment.
Regarding the performance of this amp, I was very surprised as to how well it sounds, it is truly impressive, how such a small thing can provide this output. Over all it’s pretty loud, I did not even tried more than 12 o’clock position on the volume knob, being more than enough at 9 o’clock. You can easily adjust the bass and treble and there is a nice feature since these two knobs have a click in the center, so you can put them in a neutral position very easily. In any case, bare in mind that obviously the type of speakers have a deep impact in the quality of the sound. I got my JVC passive speakers connected to the amp and I used the RCA with my Roadstar turntable and the sound is fantastic; super clear and powerful without any distortion or background noise. The bluetooth connection worked well via my iPhone with Spotify, both things paired quickly with a consistent connection, and I did not notice any disconnection/dropouts while moving around the apartment (specifications recommend to be within 15 meters). Once the bluethooth connection has been made with a device, the system will memorize it and it will connect by default the next time you switch it on. You can easily switch between sources by pressing on the volume knob for a few seconds to disconnect from the bluetooth and it will be ready to use with the RCA connection. But there is one thing that might be considered, anyone close to the amp can connect to it and it stops any ongoing connection.
All in all, I have to say that I am super happy with this amp. If you are looking for a good price-performance ratio, this product is a good candidate to be seriously considered!!
Specifications
Max Power Output: 300Wx2 @4Ω
SNR: ≥108dB
Terminating Impedance: 2-8Ω
THD: 0.005%
Power Amplifier Chip: TPA3255
Power Supply: 32V 5A
Input Range: DC 24V-48V
Frequency Response Range: 20Hz-20kHz(±1.2dB)
Bluetooth Transmission Range: Up to 50Ft
Bluetooth Codec: AAC/SBC
Audio Input: RCA/Bluetooth
Audio Output: Speaker Output/3.5mm Pre-out
Pros
Super easy to connect, no need to configurate, just plug and play
Compatibility with a wide range of audio systems
Reliability
Price
Cons
External power supply
Open acces to bluetooth to anyone
