Fosi AudioV3 Stereo Amplifier Home Audio 300 Watts x2 Power TPA3255 Class D Mini Amp 2 Channel Audio Component for Passive Bookshelf Tower Speakers Desktop Home Theater with 32V Power Supply

Don't believe the 300 watt claims of the manufacturer. (I don't know why they just don't rate the amp with RMS real world specs). Still the Fosi Audio V3 is an excellent amplifier when paired with the optional 48V power supply, although it increases the cost. With the supplied stock power supply, the amp can deliver about 30 watts of real power and with the 48V power supply it can deliver about 80 watts of unadulterated bliss. The sound is clean with absolutely no hiss. You can tailor the sound by easily replacing the socketed OpAmps inside the amp, just make sure you insert them with the proper polarity. OpAmps can range from several to over a hundred dollars for a set. Better OpAMps can give you better depth and a wider sound stage as well as a mellower sound.Remember this is a no frills amplifier with only pair of inputs, it is basically a volume knob and nothing else. But this is perfect when used as a desktop amplifier to drive a pair of desktop speakers. In this mode of operation, you do not need the optional power supply since most desktop speakers are quite efficient and do not need much power.The 48V provides a more heft to the sound with the added power. It can easily deliver enough power to drive most speakers. With either power supply, the amp seems capable of driving even 4-ohm loads without distortion which most modern amps fail to do.Some Pros:* Cheap but great value* Compact size* Very efficient* Swappable OpAmps* High quality components: Elna capacitors, WIMA Output capacitors, Sumida inductors and NCC CapacitorsSome cons:* Fosi used to supply the amp with the copper volume knob as well as the black one but it is now an added option.* The amp goes to sleep rather quickly after the input signal is cut. It takes about six seconds for it to come alive when signal is restored.* There is only one pair of RCA inputs* No Bluetooth capability* No subwoofer output

I had been hearing about the release of this amp from various forums and decided to experiment with it with a couple of speakers that I have acquired I’ve the last 6 years I or so. I’m a bargain hunter at heart.On one end, I have a pair of Klipsch LaScala’s from the early 1980’s that I resurrected from the dead. They were in horrible shape and came from a church that used them as their auditorium PA. They are know for their efficiency and usually have synergies with tube amps. On the other end, I have the electrostatic Martin Logan ESL’s, which sound completely different, are very detailed and have a reputation of being challenging to drive, although the newer Martin Logan’s don’t have this problem as much.I have been using a 90 watt per channel tube integrated amp and was really looking for an amp that was much cleaner and imparted less distortion, which a tube amp for the most part is built to do. The tube amp sounds great but it seems to blur the sound a bit, if that makes sense.With the LaScala’s, the V3 power was way more needed to drive them. It didn’t sound harsh or brittle and in fact, was completely quiet with the volume knob maxed. My tube amp imparts a slight hiss at the tweeter that is audible from my sitting position. The V3, checked all the boxes and did everything well. The highs and mids were nice and balanced and the biggest difference was with the low end. I have 2 SVS SB1000 subs and the V3 really provided nice and controlled texture to the bass region, something that was lacking in my tube amp. I won’t go as far as using the magical language to describe the sound that many audiophiles use but as this is a subjective review, what I can say is that the amp did its job and at this price, it really is a no-brainer for people that even are wanting to use this will quality speakers.Martin Logan ESL’s Challenge: These speakers are known to have dynamic impedance swings, with ohms that often dip, making them a tough act for many amplifiers. But the Fosi V3 didn’t strain at all. It provided consistent power, ensuring the ESL’s remained articulate and expressive. Much better than my tube integrated. The dips in ohms which could cause some amplifiers to falter, only showcased the stability of the V3. Very surprising for the low cost. Again, what can I say…these small inexpensive amps have improved to the point where they are an incredible value.Conclusion: The Fosi Audio V3 isn’t just a budget amplifier. It’s an amplifier that can be used with expensive speakers. For anyone hesitant to use the Fosi in similar use cases, give it a try. For the price, there’s very little to lose.

This is a rewrite after reconsideration having lived with this amp for a week. This unit replaced a Pass Class A Zen V4 which was throwing ~250 watts into the room and I wanted something physically smaller and much more efficient. This unit is smaller, more efficient and well/nicely built.While sounding different than the Pass and after making the Pass to Fosi transition my opinion is that the Fosi is a good sounding & amp and I am glad that I replaced the power hungry Pass with it. The Fosi sounds good, is small, is efficient and does what I need it do do for a very reasonable price. 4 stars because I don't believe it is capable of anything near 300 watts/channel on a continuous basis and maybe not even peak. I have the 32 volt version but will replace the power supply with 48 volts & 7.5 amps soon and it will be interesting to hear how it performs with a bigger supply.