Fosi Audio V3 Mono Power Amplifier, 240W Class D Monoblock Amp for Speakers

The four channels of the TPA3255 amp chip are all utilized in a parallel arrangement in this amp. This means the dampening factor on your speakers is x2. If you have a 6ohm speaker this amp sees it as a 12ohm load. Add to this great topology the feedback filter placed at the output stage (PFFB) and you’ve got two unique features above and beyond most class D amps in this price range or higher. It makes for a great sounding powerful amp that can drive just about anything. These can get hot so I immediately replaced the pitiful squirt of thermal compound with Thermal Grizzly Duronaut (which basically performs extremely high without drying out). I then removed the rubber feet from the bottom and strapped on a 150mm aluminum heatsink with a thermal pad between. I then use the amps upside down so the heat goes straight out the top heatsink. Normally it spreads through the bottom and around the enclosure creating a cute little oven for your components. Roll op amps to improve sound, use at least a 48V 5A power supply and Bob’s your uncle !

Excellent sound with these mono amps running them with a wiim ultra connecting with xlr connections from rca line out. The amps a very quiet and have a decent sound stage. The speakers are Martin Logan motion 40 and I was able to achieve 92db with no distortion or clipping. Compared them to the Aiyima mono amps and they felt underpowered even with the same TI 3255 chip. Since I wrote the original review I added two more of these Mono Amps to my system . My speakers have two sets of terminals so I I set up a true bi amped system. The amps paired with my Martin Logan sound incredible. The sound is actually amazing with clear definition between high and lows And what amazing low end response, my system has never sound quite this good. Theses Mono amps are connect via xlr inputs . Highly reccomend

⭐ 1 out of 5 stars Title: Great Sound, Terrible Reliability — Three Failed in 48 Hours I really wanted to like these Fosi amplifiers. In fact, when they were working, I was genuinely impressed with the sound quality. They delivered excellent clarity, strong bass, and plenty of power to drive my SVS Ultra Evolution Titan speakers. Unfortunately, that’s where the good experience ended. I went through three amplifiers, and all three failed. None lasted more than 48 hours. I had to return every single one. I’m not talking about pushing them beyond their limits or modifying anything. I was simply using them as intended in my home stereo system. It’s a real shame because I honestly enjoyed the sound while they worked. But no matter how good an amplifier sounds, it’s worthless if it won’t stay operational. Bottom line: Great sound quality means nothing without reliability. Three failures in such a short period are simply unacceptable. I can’t recommend these amplifiers based on my experience.

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 am using this to power one 12" subwoofer. I am using it in conjuction with the Rolls subwoofer crossover. This tiny little amp is amazing. The power supply is bigger than the amp. It drives a 12" sealed sub very cleanly to moderate to somewhat loud levels.

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 like it it's work good with my sub

Great sounding amp but not reliable in my experience. The first one was DOA, it didn't work at all. I returned it to amazon. The replacement was great, I bought it 4 months ago, I use it to amplify my synths in mono at home, today it's no longer working. I would buy another but being defective 2 for 2 I just don't trust it will be any better.

Incroyables ampli pour un tarif hallucinant. Équipé en 7.2.2 dans une salle dédiée hifi et home cinéma, j'ai acheté 3 amplis pour alimenter mes 3 avants Dali Rubicon. Je redécouvre la musique et les films. Plus d'impacts, plus de précision, plus de clarté, plus d'immersion. Plus, plus, plus. Ça a un impact sur l'ensemble du système. J'avais acheté l'an passé un ampli de puissance à 1400€ et 3 canaux déçu de l'amélioration. Avec ces amplis c'est le jour et la nuit Ils chauffent un peu mais sans plus dans un meuble ouvert. Je n'en reviens toujours pas du gain qualitatif. Je conseille à tous mes amis d'investir au moins pour la stéréo. Un seul inconvénient trop de fils à rajouter ( 6 rca, 3 cordons d'alimentation). Ce n' est pas négligeable mais pas rédhibitoire. Merci Fosi.

This thing rocks. Hear the finest audiophile quality.

Bought new life back to my system sounds great and compact too.

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!

Diese winzigen Monos werden beim Anblick müde belächelt. Schließt man diese an einem Vorverstärker bspw. Zh3 von Fosi Audio,staunt man nicht schlecht wie die kleinen Dinger deinen Lautsprecher im Stande sind anzutreiben. Am besten mit dem 48 Volt Netzteil. Klanglich sind diese Monos sehr Impuls-treu mit ordentlichen nicht überschäumenden Bass und akkuratesse. Das habe ich nicht vermutet. Die Monos machen einfach Spaß. Am besten über XLR Stecker anschließen und man wird nicht enttäuscht. Absolut empfehlenswert kann nur das Fazit lauten.