Fosi Audio BT20A Pro Bluetooth 5.0 Amplifier 300W x2 TPA3255 2 Channel Mini Class D Integrated Home Audio Outdoor Stereo Amp Receiver for Speakers Supports 24-48V with Bass Treble Control

This is a honest review of FOSI BT20A PRO.After trying a few Inexpensive yet good class D amps, I decided to go for the fosi bt20a pro, as its based on Tpa3255 and has the bluetooth & rca connection options (till 6.months back there were too few BT amps from fosi or aiyima)Here is my reviewBuild :Pretty solid, everything is upto the mark, the aluminium used high grade anodised one, no creaks and squeaks anywhere when you hold the amp.All the three knobs (bass treble and Volume) are sturdy but somehow the one I got had a kinna wobbly volume knob, dunno if it's just me or this is the way it is.The back connectors and sockets are placed pretty close to each other but with some small maneuvering everything can be pushed, tied and fixed.AccessoriesThere comes a bluetooth antenna the standard one & decent enough, which you have to add yourself.POWER SUPPLY : the amp is rated to work from 24v to 48v power supply but is shipped with a Fosi branded 32V 5A one.. It does what is expected of it and the output is sufficient..(at lest fir my use case scenario is more than enough)The wire provided with the power supply adapter is of adequate length, the block and wires all look decent and feel study enough . Checked its voltage and it does produce what is claimed 32.4V to 32.5V.Functionality..Bluetooth connects in a jiffy and the coverage is good.Kinna tricky sometimes to get the connection changed but by and large it's easy to switch from BT to RCAThere is also a socket of 3.5mm pre out at the back which can be used to supply signals to an active subwoofer which is awesome in my view... But I don't think I ll ever need that because the amp giving enough thump already with the pair or my Sony passive speakers. This same socket can be used to connect this amplifier as a preamp to another amplifier if you want..ONE VERY IMPORTANT THING :The amp comes with replaceable op amp chips, (which require the user to remove the screws and slide out the motherboard and then chnage the op amp chips) the more enthusiastic audiophiles who like to experiment with different sound signatures can change them according to their preference.. FOSI has suggested a number of op amp chips that one can try after purchasing them from market or from online.. (there a few available at Amazon India as well)In my personal view it is sounding pretty good as it is so for majority of users there is absolutely no need to experiment with the op amp chips.Audio qualityPlease note I use my SONY BOOKSHELF SPEAKERS with this.. The one which came with my Az2d music system they have a kind of plasticky cone hence the bass is pretty tight and I love that.Via Bluetooth it sounded pretty decent (please note I use Spotify with highest streaming audio quality on an iPhone)Through RCA I stream via my Google chromecast audio and the sound is fantastic.Over all its pretty loud, the tone knobs do a good job and the best part is there is a neutral point for both bass and Treble exactly in the center so you get a good reference point..The low freq response is awesome which is genuinely deep and tight, the high freq are pretty good too but may be a bit more wanting like 10% lesser than the bass response... But that's just me... Over all it has played everything nicely that I have thrown at it... Mids are pretty good ( as you are to manage the mids via your preamp etc, you can further enhance them as well)Be it the jazz, or Bollywood music, or ghazals by Mehdi Hassan and Live Indian Classical renditions in both vocal and instrumental, it played everything nicely (of course you have to adjust the knobs according to the type of music as well as the source quality)Edit : after using for more than a month I can say the sound is pretty neutral and with a wide stage, the high frequencies need a tad extra kick for my liking so I am trying to arrange a preamp now to boost the quality further..But one thing is for sure, via Google chromecast audio (which technically means that there is a proper DAC before the RCA input (as the GCA has a dedicated DAC in it) this thing just sounds so great..Please note : type of drivers (speakers) plays another huge role so please use atleast half decent ones with these...All in all I am pretty happy, would have loved a fully functional remote and a knob to manage the mids too (I know that's tricky)Would have loved to have couple of more connectivity options like optical etc but I know I will never use them so doesn't matter, but having them would have been great even if just for academic purposes...In the end I can safely say that its a pretty good small packageWould highly recommend it as tpa3255 chip perfoms extremely well and with its implementation on the fosi board it produces very loud audio without much distortion... There is no hissing or clicking when the amp is idle and it doesn't get hot (that much) as well..Thanks

I have been thinking about setting up a music system that delivers amazing quality for a small space, especially for long listening sessions. Using in-ear pods for extended periods can be uncomfortable and potentially harmful to the ears, so I decided to repurpose some of my existing speakers that hadn’t been used in a while.My setup includes a MacBook Pro, connected via the 3.5mm jack to the Fosi BT20A Pro amplifier, driving Polk RTi FXi A6 surround speakers. I’ve chosen this configuration because the FXi A6 offers a frequency response that suits my needs perfectly. I primarily use Apple Music, streaming at 98 kHz, and the results have been impressive.To further enhance the audio quality and fully utilize Apple Music Hi-Res, I bought the Fosi DS1 DAC. After adding the DS1, the total listening experience became phenomenal. Thank you, Fosi, for such innovative products at such great prices. Need not spend lakhs of money to hear the same music.Design and Build QualityOne of the first things you’ll notice about the Fosi BT20A Pro is its solid construction. The metal housing gives it a premium feel, and its compact size makes it easy to fit into any setup, whether on a desktop or as part of a larger home audio system.Sound Quality: The sound is clear and well-balanced, with a good sense of depth and detail. The amp does a great job of driving speakers to their full potential, delivering crisp highs, detailed mids, and punchy bass. With the addition of the Fosi DS1 DAC, the audio experience reaches new heights, fully capturing the richness of Apple Music’s Hi-Res offerings.Low Noise Floor: Even at higher volumes, the amp remains quiet, with no noticeable hum or hiss. This makes it a great choice for critical listening in quieter environments.Value for MoneyGiven its price point, the Fosi BT20A Pro offers excellent value. It’s a budget-friendly option that doesn’t skimp on quality, making it an ideal choice for those looking to upgrade their audio system without breaking the bank.• Affordable: Considering the performance and build quality, the BT20A Pro is priced very competitively. It offers features and sound quality that you’d typically find in more expensive models.• Long-Term Investment: Thanks to its robust build and reliable performance, the BT20A Pro feels like a piece of equipment that will last, making it a sound investment for any audio enthusiast.ConclusionThe Fosi BT20A Pro is a fantastic little amplifier that punches well above its weight. It offers great sound quality, versatile features, and solid build quality, all at an affordable price. Whether you’re a casual listener or an audiophile on a budget, this amp is sure to impress. With the addition of the Fosi DS1 DAC, the listening experience becomes exceptional, fully taking advantage of Hi-Res audio formats.

This product carries a punch. It is pro audio stuff. You would be surprised by its small size. It comes with 32 volt power supply. But if you use 48 volt one, I have read that you can almost double the output power to the speakers. By the way, do not expect 300W RMS output from it. It is much below than that. According to detailed measurements done at Audio Science Review site, its true RMS with 48v input power adapter is about 80 to 90W. A 32v adapter may give much less than that. But still it is more than enough for a small room with a pair of good quality bookshelf speakers. If your speakers are not audiophile grade, then you may not be truly appreciate the sound quality of it.It has reasonable punch on low to medium frequency ranges, and distortion creeps up slowly at higher frequencies. Using the treble control, you may reduce its effect, but not completely.The bluetooth is not state of the art. But still it is good enough for this price-range. I have not tested the RCA inputs yet. But according to the reviews on the net, that too is not bad.It is quite good for vocals, and acoustic guitars etc. At this price range, it is difficult to get a better product.