Fosi Audio BT20A

Last year I had bought a Tangent Ampster BT II amplifier, which had worked great, however it recently had an issue with the power switch, so had to be sent away for repair. As I used it in my office I needed a replacement and decided to order this amplifier. I thought the Tangent Ampster was small, but this BT20A amplifier is ridiculously small! This is mainly as the power supply is external to the amplifier, which itself is bigger than the amplifier. I have it connected to a pair of Mission LX-1 MKII speakers, and I am happy to say that this amplifier easily runs these speakers, with no sign of distortion. I appreciate the treble and bass controls, as by default the treble did sound lacking and a bit stifled. The dials are nice and smooth, and the power switch toggle works without issue. At this size and price you only get 1 set of RCA inputs and 1 set of speaker outputs, but for my use case this is fine. Bluetooth works seamlessly, and the audio quality is about on par with direct RCA connection. Be aware that if you connect via bluetooth it will override the RCA input, even with no music played over bluetooth. I will say, as others have, that being able to connect to the amplifier via bluetooth without being asked for a code is a potential issue, I live in a block of apartments, so anyone could connect to it if they tried. I don't hear any hissing when not playing music, so that is another plus. Overall a great little amplifier for the price, once my other amp is back from repair I will probably relegate that to the living room as it has a remote control that is more useful.

I bought this on a whim and it has turned out to be an excellent purchase. I bought it with 15% off so it was just over £70.00 and at that price I feel it to be very good value indeed. It is certainly a small amplifier and ideal for anyone with limited space. It has metal casing and feels very solidly built. This gives me confidence as so many items seem flimsy these days. I use it mainly with a CD player and the sound quality is superb and certainly loud enough. Using it for streaming over Bluetooth is also excellent. The only downside is that I find the volume etc controls a bit small and fiddly to adjust. Not a major problem really but a remote would have been nice even if increasing the price slightly. I was so impressed with it that I also purchased a BL20A a few weeks ago. That too is an excellent amplifier and I have reviewed it separately. Overall I cannot fault Fosi products and would not hesitate to buy from them again.

I used this unit to drive pair of floor-standing speakers which I use with my PC (I like decent sound quality). This unit delivers punchy bass with no background noise on either the aux input or via Bluetooth. I'd had background noise problems with the previous amplifier (a Tangent 50W per channel unit), probably due to a ground loop. The Fosi BT20A unit background noise is completely inaudible. The unit is also very small (about 1/10 the size of the amp it replaced) but with the same output power. This is probably due to the fact that it is a Class D amplifier which makes it very efficient. It is more than capable of filling the room with sound at concert hall levels. The only issue I've had is that occasionally the Bluetooth input will not reconnect after the PC has been asleep. This is easily solved by briefly cycling the BT20A power. In short, I'd happily buy another.

I bought this Fosi amp (BT20A) 2 months ago having read mixed, but mainly good, reviews. I have it connected to a pair of Maudant Short MS20i speakers which were previously connected to a big Technics amp. I'm not an expert on sounds, but I like a good sounding stereo, and this amp with music from my phone (spotify) bluetoothed to it is great. It's plenty loud enough for an average living room and the clarity is excellent, and the adjustments for bass and treble are simple and effective. I think it's as good as the Technics amp (SA-EX320) soundwise, but much simpler with a lot less functions - but it does have bluetooth! I listen to music from my phone via bluetooth, and I have the optical out from my TV through a converter into the RCA inputs. Both sound great (to a non audiophile) with the only very slight issue being that occasionally when the TV is off and nothing is connected to the BT, if the volume is high some small clicky noises can be heard, but that may be the cheap optical to RCA converter I am using. The power supply is a bit of an eyesore compared to the sleek little amp itself, so I had to hide that (and a load of other wires) in a cable tidy box. The picture shows how tiny it is next to a Tivo box. I'm really glad I bought it and I would happily buy another if needed, but I am a bit miffed that in the 2 months since I bought it the price has dropped from £70 to £60! It is a bargain.

Bought this to improve TV sound . Very small footprint and does not get hot at all. 24v power supply tucks out of the way, ad also runs fairly cool. Bluetooth connection, which I was forced to use because of my TV, is quick, easy and reliable. Power output is seriously good into a high quality passive speaker that is quite challenging to drive, and more than adequate to fill a large room Sound quality is very good and the bass and treble controls have a good range of operation. The three rotary controls have a good 'feel' to them and the entire unit is nicely finished. Altogether - A Terrific Little Amplifier', and highly recommended. David

This is the perfect answer for powering hifi speakers with a physically small amplifier. I have had this for two years now, and it is faultless. In use with some old Bose speakers it produces a warm tone in a modern room with nothing to absorb the sounds (so it could be a bit harsh). I tried a much more expensive amp, with a graphic equaliser, and the little Fosi is far better to listen to. Treble and base contols give any amount of tone adjustment. Sometimes I listen to things from my phone and the bluetooth is 100% reliable; it has never once gone off or distorted the sound. The amp switches itself from wired input to bluetooth as soon as you connect your bluetooth device, (there is no selector switch or anything like that). For the pc sound I am wired in. You have phono plugs for your input and banana plugs for the output, but for the output you could just have bare wire without plugs. You can see everything behind my computer screen, with a Bose speaker next to it. The speaker is 6½ cm wide, for scale. I can definitely recommend this amp.

I brought the first amp a while ago and sent it back as I wasn’t happy with the sound quality or output. I think I said it may be ok for a small broom cupboard. Roll on 2 years or so and having re-read the reviews I decided I would give it another go With a fresh set of ears Maybe I had a bad one last time of they have tweaked the firmware or something, But it’s a very different amp from the one I recall - To my surprise this one was excellent- I would say unbeatable for the price. Ok so some complain that the Bluetooth is not protected so anyone can jump on it and that would be a nice extra but it is what it is. It’s driving a couple of external speakers with a well known home assistant input for the garden and I’m seriously impressed. Also tried some mission bookshelf speakers I had spare. Bass and treble are adjustable and work remarkably well. Bluetooth seems solid and clear; aux in is even better. Recommendation: set bass and treble to 50% (pointing straight up) as a starting point, this will give you a good reference point. I’m really fussy about sound and wasn’t expecting much but I’m really glad I gave this little beast a second go. I would absolutely recommend for small or mid size room.

Despite returning this amp, I have to give it 5 stars for value for money. If your only going to use the RCA input the sound is pretty good and filled a 14’ square room with ease. It was very quick to discover all my devices via Bluetooth. However for me the reproduction via Bluetooth was a disappointment (I tried iPod and Amazon prime music via both iPad and laptop) and reproduction was dull and lifeless. I accept that reproduction will never be as good at this price level, but the difference between the Bluetooth and the RCA Input was just too marked for me to live with. I was looking to spend far more on a new amplifier than this, but thought I would give it a try as it had such glowing reviews. So went for a Mission Cyrus one HD, yes it’s over 12 times the price, but Bluetooth reproduction is as good if not better than the RCA input of the Fosi. It would be very unfair to bad mouth this little amp, as if your just going to use the RCA Input this little fella punches well above its weight, just don’t expect the same quality of reproduction when using Bluetooth. Simon.

高品質なサウンドが楽しめて喜んでいます。テレビとは有線で、スマホとはBluetoothで接続。Bluetoothで繋ぐとテレビの音は消音されるので、外部入力よりBluetoothを優先します。 シンプルで小型なのにパワフルで喜んでいます。

Mój amplituner Onkyo zajmował miejsce w moim minimalistycznie urządzonym salonie , dodatkowo nie posiada bluetooth , więc zakupiłem Fosi Audio , i.... Nie jestem melomanem i pewnie dla tego :-) nie słyszę różnicy między tymi wzmacniaczami , więc polecam wam też bo większość z was tak jak ja jej nie usłyszy

I’ve had it for a year and no problems, great sound

I have been using this amplifier for a month now. It is working without any issues. The build quality of the amp as well as the adapter is very good. Looks tiny besides my old amp. My Old amp stopped working so am using this amplifier as an temporary alternative to power a set of Solidaire SS100 bookshelf speakers with a 12-inch woofer, a 4-inch midrange, and a 1-inch horn tweeter with impedance of 8 Ohms. Bluetooth range is also good. Comparable to my existing Logitech Bluetooth adapters. I have noticed it does not get warm on long usage when listening at acceptable volumes at home. The audio quality is flat and commendable in the Fosi amp, but I seem to miss the warmth my old Solidaire AS1200D amp provided. So, I tend to boost the lows and mids from the equalizer to get the desired effects. My decision on buying this over Aimyia amp was swayed because FOSI provide a warranty on their product, but Aimyia brand amps have no such mention in their listings.

Hands down this is one of my favorite amps to use. From the compact design, east of use, and power. It certainly offers a lot of value. The Bluetooth connects consistently each and every time, something that I often found a challenge with similar products. The audio quality is fantastic out of a small package. Whatever I throw at it, it just handles it. Be it my customer built enclosures or my reference Klipsch speakers. The connectively makes it easy to get up and running in no time without any hassle. Highly recommend for anyone wanting to add Bluetooth functionally in there space or wanted a tiny amp for some bookshelf speakers. This is the one!