Fosi Audio V3 Mono Power Amplifier for Home Audio Speakers, Mini Monoblock Class D Amp with TPA3255, 240W for HiFi Home Theater AVR Receiver Component, RCA/XLR Balanced Inputs 48V/5A Power

I researched Fosi Audio amps and really all there audio components for a couple months, and ended up ordering two v3 mono blocks along with the zp3 and zd3 preamps and from my research found it was a good idea to order the cooling fans as well, and I did. The quality of there products are absolutely the best, and they work and perform just beautifully, for me the sound quality deserves way more than 5 stars. Fosi Audio makes a great product at very affordable price! Happy I bought this and very satisfied!

I first encountered the Fosi monoblock V3 for use in a music-only system and was blown away by its transparent sound and high power for such a tiny box at such a low price. I began to think about deploying more of them as a possible upgrade for an older (but top of the line) Onkyo Dolby Atmos AVR in a 5.1.2 Atmos layout, using the Onkyo's preamp outputs rather than the internal amps. So far I have installed 3 of them, powering the from L & R and the Center Channel. As I expected. everything sounds better. The sound is more detailed and accurate, imaging is more precise, dialog emerges more clearly from other soundtrack elements. I look forward to soon adding more V3's to complete the surround channels and the height speakers, but the listening experience is already so impressively improved. The way these amps power on and off based on detection of signal has functioned perfectly with no delays, popping sounds or any other negative aspect. They just work. I was always pleased and proud of the high fidelity of my AVR, but this has been an extremely high value upgrade that has put it into a whole other category. HIGHLY recommended!

The Fosi Audio V3 Mono Power Amplifier definitely has its place. It seems it would perform well with small to medium-sized speakers. However, the rated 240W output feels optimistic. I didn’t put it on a scope, but in practical use it seems better suited for lighter loads rather than large, power-hungry subs. I tested it on a 12" in-ground subwoofer and had to set both the amp’s gain and the Sonos sub output to their maximum just to get reasonable movement from the driver. My concern is that this likely pushes the amp’s output stage close to its limits, which could risk long-term strain or even damage. As other have mentioned, this amp gets extremely hot. That said, it’s a great value and serves a useful role as a compact, affordable mono-block amplifier, especially as an add-on to a Sonos system to drive small to medium sub. I’d love to see Fosi release a higher-power version of this amp with the same balanced input options and clean design. Solid little amp with great features, but limited power headroom.

I wasn't expecting this much from a device like this. I have two 12 infinity subwoofers that are dual voice coiled. My thought was to give these a try in the off chance they can actually push the sub. I tried both 8 and 2 ohm configurations on one subwoofer and I am really impressed. 8 ohm, the subs were happy, I would guess they were getting around 130-140 watts as expected. The damping is impressive with 8 ohms as everything sounded amazing and tight with true accuracy of the sounds it was able to produce. When I tried 2 Ohms, that is when I laughed out loud due to my shock on how much current this thing can produce! I'm not going to say it was crazy but it was truly getting there. I'm not sure if this can double the power at 2 ohms but it did seem to be producing more then 300 Watts RMS with ease. I have a 400 Watt RMS amp and this thing is right up there with it. My plan now is to get 4 of these and pin each amp to a voice coil to provide 480 Watts RMS (240W per voice coil) to each subwoofer. While it performed well at 2 Ohm I feel a 4 Ohm load might be a slight bit better on damping. For the price these things are absolutely amazing, I am now figuring out if I need to run a dedicated 20AMP service for my audio equipment cause these alone will draw 14 Amps when they hit. I'm pretty sure I will trip the circuit breaker on a 15AMP with the rest of my gear if I don't upgrade it.

I have had this for two weeks and I will update if I find any discrepancies in my review. I am using this on a homemade 10'' floor facing subwoofer that I did not make and I really do not know what speaker is in it but the cabinet and speaker weigh about 70 LBS. My system that I am using is an Onkyo TX-NR727 that has 110 watts per channel. This amplifier works fine and keeps up the volume with the reciever. There is no cutoff/tone or volume adjustment as it just uses what is sent from your receiver or preamp via RCA or balanced XLR jack (I am using an RCA). It took me forty-five minutes to an hour to find the sweet spot that would be good for a variety of music. After a short while, at high volumes, it gets somewhat hot and this is challenging to what I know 'run cool' about Class D amplifiers but since it is small they probably use the case as a heat sink. Since the Sub is floor firing, I do not notice any distortion. The Auto on and off sensing works.

1 out of 3 was defective , it powers on but no sound. The remaining two work great, they do seem a bit too hot. As long as it doesn’t break in next some years, nor interfere with the sound heat doesn’t bother me. One thing to note there is much louder sound when I use RCA input vs XLR I had to add +9 db on my receiver for same volume. Also there is a some noise when using RCA to RCA, XLR has almost no noise. My receiver unfortunately doesn’t have XLR output, I just use RCA to XLR cable. Works great, no interference noise, only downside is I have to +9db on a receiver. I hear lots of people adding Sparkos OP amps. Is it worth it I wonder?

I purchased a set of two monoblock amplifiers for a typical 2 channel stereo system. However, as others have pointed out, I also received two different types of power supplies. The specs look the same, 48v at 5A, but different styles, one larger than the other and different power-on indicator lamps, and probably from different vendors. I would expect a matched pair both aesthetically and electronically. Second problem was that one of these two amps doesn’t go into sleep mode when the audio signal isn’t present after time. Third problem is that one amp has a very dim power on LED that’s somewhat difficult to see except in darkness, especially when viewed from an angle. All that said, the audio quality of both amps has been excellent. Yes, as others mentioned they do run quite warm if you push them beyond about 10 watts input. I don’t drive them very hard so heat should not be an issue in my case. But, for a 240 watt capable amplifier, even running in class-D, I think they should have a better, more beefy, finned heat sinks. Nobody wants to listen to fans if we can avoid it. But we don’t want to see our amplifiers burn up and fail either. Again sound quality is excellent. I ended up buying a third amplifier in hopes that it would match one of the two amps I originally bought. It matches the amplifier with the dimmer LED, so I will return the one that had a brighter LED and wasn’t appearing to go into sleep mode. After buying three of these monoblock amplifiers, I concluded that these have either undergone parts revisions or are being manufactured by more than one vendor. Looking closely, I can see the indicator LEDs are of slightly different models, one being noticeably brighter than the other. Same thing with the power supply bricks being physically different sizes but of similar specs electrically. The manufacturer could prevent these inconsistencies by putting a revision number on the box label or changing the model number slightly. Otherwise, you can expect to possibly not receive matching parts. All that aside, they sound great and don’t seem to run too hot as others had mentioned. They get quite warm though, and cooling can be made better simply by putting taller feet on the bottoms for better air circulation. Fosi has a good product, but needs to place more attention to consistency details. I’d gladly take it to 5 stars if quality control was better.

I ordered a pair of these to use with my Magnepan LRS+ speakers, replacing a Parasound HCA-2200A amplifier. I don't feel like I'm missing anything after the switch, which in my opinion is the best you can ask for from an amplifier. They put out more than enough power for these speakers and stay much cooler than the Parasound while doing it. And they are so small! The binding posts on the back are smaller than standard so don't expect to put banana plugs into these. That's not a problem for me since I like to put the bare wire under the binding post anyway. Overall these are a great value for the price. If you're not convinced, check out the measurements on the Audio Science Review website.

These are tiny but performance is like beasts. Clear and punchy sound paired with Polk ES20. Loving it

This thing rocks. Hear the finest audiophile quality.

Fosi Audio V3 Mono. A couple weeks ago i recieved 2 V3 mono amplifiers i'm very pleased with them! They sound incredible with my aune S9 c pro dac with trs out from V3 mono in to my S9C dac with xlr female.Incredible value higly recommended!

I had read some reviews, as I am interested in this market a lot, already owning a Fosi V3 and a pair of Aiyima A07 Max's... I had very high hopes for the Fosi V3 mono amps, and was not disappointed! Fresh out of the box they were a little tight and congested sounding, just a bit-no blooming of the sound... Well, 5 hours later and wow!! What a difference! The sound-stage is deep, wide and very clear, with no shortage of power, that's for sure! They sound so good they have already replaced my other monoblock amps! Bass is deep and very tight, the midrange is clear and open, highs are not shouty but again clean and well balanced top end. Excellent input choices (RCA and XLR) and simple controls... Having heard several of these TI 3255 chip amps, all have a similar sound, but the additional realism of the V3 mono is quite audible! And you can swap audio op-amps as well! A killer deal on the amps right now! Buy a pair- you won't regret it! :) Edit: I've been listening to these V3 mono amps for about a week now, and I am BLOWN away by the amount of sound these amps reproduce! True giant killers! I'm more than pleased with these amps! Buy some! :)

Ao longo dos anos, sempre associei a minha paixão pelo áudio ao som quente e orgânico de um amplificador a válvulas. Para mim, as válvulas representam musicalidade, textura e aquela sensação quase “viva” na reprodução — algo difícil de explicar, mas fácil de sentir. O brilho suave nos médios, a riqueza harmónica e a naturalidade das vozes sempre foram a minha referência sonora. Ainda hoje utilizo um sistema com pré-amplificação a válvulas, nomeadamente um Sonic Frontiers, que continua a ser o coração do meu sistema. A sua assinatura sonora mantém aquela fluidez e tridimensionalidade que tanto aprecio. A ligação é feita através das saídas balanceadas XLR, garantindo um sinal mais limpo, melhor rejeição de ruído e maior estabilidade na transmissão — algo que considero fundamental para extrair o melhor desempenho possível. Movido pela curiosidade e pela evolução tecnológica, decidi experimentar algo diferente na etapa de potência: o Fosi Audio V3 Mono, um amplificador Classe D compacto, moderno e surpreendentemente competente. Confesso que as expectativas eram moderadas. Sempre associei Classe D a eficiência e potência, mas não necessariamente a emoção ou refinamento. A verdade é que fui surpreendido. Com o pré a válvulas da Sonic Frontiers a alimentar os monoblocos através de ligações balanceadas XLR, encontrei uma sinergia muito interessante. A riqueza harmónica e a suavidade do pré combinam-se com a rapidez, controlo e autoridade do Classe D. O grave é firme e articulado, com excelente controlo, a imagem estéreo é estável e precisa, e a transparência geral do sistema impressiona. O carácter sonoro é diferente de uma amplificação totalmente a válvulas, mas não é inferior — é simplesmente outra abordagem. Mantém-se a musicalidade graças ao pré a válvulas, enquanto a etapa de potência Classe D acrescenta eficiência, silêncio de fundo e uma capacidade dinâmica notável. Esta experiência fez-me repensar alguns preconceitos. A tecnologia Classe D evoluiu imenso e já não é apenas uma solução prática ou económica: é uma alternativa séria e audiófila. O Fosi V3 Mono mostra que é possível ter desempenho de alto nível num formato compacto, eficiente e moderno. Continuo a admirar profundamente a amplificação a válvulas, que faz parte da minha identidade sonora. Mas hoje reconheço que o Classe D já não é apenas o futuro — é o presente. E com a combinação certa, como um excelente pré a válvulas e ligações balanceadas XLR bem implementadas, podemos ter o melhor dos dois mundos. No final, o que importa é a música. E se esta combinação me faz redescobrir álbuns e prolongar sessões de audição com um sorriso no rosto, então talvez o futuro já esteja mesmo aqui.