

🎵 Small Amp, Big Vibes: Power Your Sound, Own Your Space
The Fosi Audio BT20A Pro is a compact, high-efficiency Class D amplifier delivering 300W per channel with Bluetooth 5.0 wireless connectivity. Featuring customizable bass and treble controls and replaceable Op-Amps, it offers audiophile-grade sound tailored to your preferences. Its minimalist design and easy setup make it the ideal upgrade for home or outdoor passive speaker systems, combining powerful performance with sleek portability.















| ASIN | B07JVFY27T |
| Best Sellers Rank | #4,135 in Electronics ( See Top 100 in Electronics ) #7 in Audio Component Amplifiers |
| Brand | Fosi Audio |
| Customer Reviews | 4.5 4.5 out of 5 stars (2,488) |
| Date First Available | December 22, 2018 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 2.42 pounds |
| Item dimensions L x W x H | 5.59 x 4.21 x 0.16 inches |
| Item model number | BT20A PRO |
| Language | English |
| Manufacturer | Fosi Audio |
| Maximum Supply Voltage | 32 Volts (DC) |
| Minimum Supply Voltage | 32 Volts (DC) |
| Mounting Type | Surface Mount |
| Number of Channels | 2 |
| Output Power | 300 Watts |
| Package Type Name | box |
| Product Dimensions | 5.59 x 4.21 x 0.16 inches |
| Specification Met | [If Interpreted as Technical Specifications]: Bluetooth 5.0 |
| Voltage | 32 Volts |
K**Y
Shockingly Good Little Amp — Perfect Drop-In Replacement for an Outdoor BBQ-Island Setup
I bought this little gray superhero after my previous “mystery box” amplifier (buried deep inside my outdoor BBQ island like some kind of archaeological artifact) decided to cut in and out every time I turned the music up past “mellow backyard vibes.” Nothing kills a good afternoon faster than your speakers crackling like they’re coughing up dust. 📦 First Impressions This thing is tiny. Like “did they ship me the right item?” tiny. But don’t let the size fool you — it punches like a heavyweight. Bluetooth range? Strong. Power? More than enough to drive the 6.5” Aquatic AV outdoor speakers I already had wired in. 🔧 Installation (AKA: How I Crawled Into My BBQ Island and Survived) My previous setup looked like NASA mission control. Wires, harnesses, proprietary connectors, and something pretending to be a subwoofer box. The Fosi made the whole thing simple: • Speaker wire → into left & right terminals • Power adapter → plug • Bluetooth → connect • Music → immediate happiness No proprietary weirdness. No random 4-pin blue plug. No tears. 🎵 Sound Quality Compared to my old Aquatic AV amp, which acted like it had seasonal allergies, the BT20A Pro is clean, strong, and shockingly loud for its size. • Bass is smooth (especially with your speakers’ built-in low-end) • Highs are crisp • Mids are clean • And the bass/treble knobs actually do something instead of just pretending Honestly, for a backyard setup that sits in a protected cabinet, this little thing is the perfect “sweet spot.” 📡 Bluetooth Fast pairing. Zero drama. I walked almost to the front yard before it even hinted at disconnecting — which, for anyone with an outdoor entertainment setup, is basically sorcery. 🔥 The Verdict If you want: ✔ A simple, clean replacement for a dead factory amp ✔ Power that actually moves your outdoor speakers ✔ Bluetooth that doesn’t quit ✔ A device that you can install without needing an engineering degree ✔ Something small enough to hide anywhere …then this is exactly the amp you want. 😂 Bonus Humor Section My old amp weighed 10 pounds and sounded like it had asthma. This Fosi weighs nothing, and sounds like it drinks pre-workout. ⸻ ⭐ Bottom Line: For the price, size, and performance, this little amp is the MVP of my backyard. If Fosi ever makes a “Pro Plus Ultra Nuclear Edition,” I’ll be first in line — but until then, this thing is staying right where it is, working flawlessly while I grill, chill, and pretend I’m an audio engineer.
K**H
Great Little Integrated Amp!
Great Little Integrated Amp! Very well made of all metal. Easy to assemble and set up. Bluetooth was easy to connect and works great. This little amp has lots of power and sounds great. Runs warm but not hot. A great inexpensive alternative to large, more expensive integrated amps.
P**R
Amazing Clean Powerful Streaming
I admit that I have little knowledge of audio And electronics. I thought 300 watts of audio power had to come from a big heavy expensive amp. My new house came with 8 ceiling speakers . I had no idea whether they worked or sounded decent. The previous owner left an AVX speaker selector next to a bunch of speaker wires that were coming out of a wall port. I called Cambridge Audio and an advisor told me I would need to buy an amp costing at least $600 to run the speakers. Since I had no idea how it would sound , i looked on Amazon for an alternative. I took a chance on this tiny inexpensive Fosi amp to see if the setup even worked. It turns out that 3 of the 4 zones work and each sounds great using my phones Bluetooth and Apple Music through the Fosi into the speaker selector . I am being cautious with this setup , but I have determined that I can definitely power three zones simultaneously at rockin’ volume. The bass is not earth shaking , but is ok. I am amazed at the sound . Since the speaker selector has an impedance protector switch, I am relatively certain that I will be able to run 3 zones simultaneously without blowing out the speakers. I think the Fosi Amp is great . I am not audiophile and have reasonable expectations. The amp has an 18 month warranty. It is tiny and the Bluetooth is so strong that I do not have to leave my phone next to the amp. I highly recommend this tiny Bluetooth amp.
S**I
Solid Sound and Easy Setup for Patio Vibes
I’m running this amp with four Yamaha outdoor speakers, and it sounds pretty good. Don’t expect it to be super loud like a big home theater system, but it has plenty of power for hanging out on the patio or in the backyard. What I really like is having full control over the bass and treble—makes it easy to tune the sound just the way I want it. The Bluetooth setup was super quick and simple, paired right away and hasn’t given me any issues. Overall, it’s a solid little amp. Simple, reliable, and the music comes through clear. Perfect for casual listening outdoors.
C**R
Nice little bluetooth capable amp. buy it with the 48v power brick if you can
Rather nice ittle amp with great specs. The power brick it came with was the 32v/5A. It can take a 48/5 power brick, which is strongly preferable. For one thing, cleaner, "effortless" bass, even at lower volume, and you get more distortion free watts. important: Buy it with the 48v PSU, from somewhere where you can chose that option. With that, it would be 5 stars . the stated wattage is optimistically stated. The usable wattage will be limited by the amount of distortion you can tolerate. With 8 ohm speakers, and the 48v brick, I guess you get maybe a clean 50W per channel, maybe. little more. The Amazon description may lead you to think that it comes with the 48v power brick, because it mentions 48v. What that really means, this unit "can take" up to 48v power. You may want high efficiency speakers with this. I use Infinity IL10 bookshelf speakers, and tried with Klipsch RP 820F-s both work great.
E**C
Great amp!
Easy to setup, boosts power from a home-built desktop just as expected. It's got the bass and treble, and a extra EQ software on my desktop allows the sound to flow out with richness and ease. Well worth the cost, it does exactly what I wanted it to. Don't underestimate -- size doesn't matter!
A**B
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 review Build : 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. Accessories There 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 RCA There 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 quality Please 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 package Would 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
M**Ş
Ürünü fiyatına göre değerlendirmenin daha doğru olacağı kanısındayım. Dali Oberon 3 ile kullanıyorum. Boyutuna göre, gerek detay, gerek bas ve tiz performansı olarak memnunum. Hızlı ve sorunsuz teslimat için Amazon'a teşekkürler.
A**E
It seems that I got a particularly broken unit, in which the Bluetooth module caused an annoying crackling and buzzing sounds. The manufacturer's support team was simply professional and I was positively surprised by the level of understanding and support I received.
D**Y
Estuve comparando diferentes amplificadores de clase D para conectarlas a unas bocinas polk de exterior, entre ellos Nobsound y Dual, en alternativa a comprar un SMSL ya que sus precios son más elevados. Su tamaño compacto me pareció muy conveniente para su fácil almacenamiento, en comparación a otros como el Dual que es mas grande y voluminoso. Leyendo reseñas y viendo diferentes criticas de youtube me decidí por este amplificador Fosi, vi que un problema recurrente era la pobre conexión vía bluetooth, por lo que de antemano decidí comprar un adaptador para esta función, se puede conectar por los puertos RCA o por AUX. Probé la antena bluetooth que trae el producto y no me pareció mal si solo quieres tener un dispositivo conectado, pero si como yo, buscas que sea fácil cambiar entre dispositivos para reproducir audio y tener un rango mas amplio de conexión, te recomiendo comprar un adaptador multidispositivo con mas alcance. La calidad del sonido es muy buena, se puede apreciar bastante bien el sonido y tienes 3 controles para hacer modificaciones. Los controles de bajos y altos, hacen un buen trabajo pero nada excepcional, lo cual es aceptable por el precio del producto.
G**R
Heel klein toestel, stevige constructie, groot vermogen, uitstekende klank, wordt niet warm zelfs na 12 uur continu spelen. De Bluetooth werkt snel en perfect. Heb o.a. toestellen van Denon, Yamaha, Technics sedert jaren. Deze Fosi komt aardig in de buurt wat betreft geluidskwaliteit. Ik heb dit toestel gekocht na het lezen van massa"s reviews van over de hele wereld. Gewoon aangeschaft uit nieuwsgierigheid, en zoals de meeste bezitters ervan, aangenaam verrast door de kwaliteit en vermogen. Geen vervorming bij hoog volume, natuurlijk in combinatie met goede luidsprekers. Levert prima prestaties dit kleine ding. Voor zo'n prijsje bij Amazon deze kwaliteit en prestaties, niet twijfelen.
Trustpilot
2 weeks ago
3 weeks ago