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 with 48V/5A Power Supply

Wasn't sure if these were going to be a 4 or 5 star review. As other commentators have said, they do run hot; burning hot, over 60C. They sit at 40C in standby. I worry about the heat affecting electrolytic capacitor lifespan.I bought four for my bi-amping project, (I was replacing my 4 channel 3886 hybrid 'scraplifier') and the quiescent current draw must have been enormous.So, on advice, I replaced the 48v psu (x4) with a 32v psu (x4).It added an extra hundred quid to the project, but I was eight hundred in to it by now, so it seemed rude not to.And, WOW, I'm still producing 100w (x4) into 8 ohms. And with a usb dac, everything reaches FSD (full volume) at the same point.And now they run 'cool' at about 40C in-use and just above room temp in standby.Sound? Acoustically invisible.Confidence? Much better.Value for money?...Well, it works for me. You'll have to decide for yourself. Four and a half stars.

Bought as an additional Fosi V3 monoblock to compliment 4 other V3 mbks to drive a centre channel speaker, to sonically match my mbk/bi-amped front left & right speakers.This proved to be effective by sounding just as crystal clear, detailed & dynamic as my left & right speakers.Although its tonal balance is slightly bright, voices sound articulate without sharpness or edge.Music is equally enjoyable through it when playing multi-channel tracks from DVDAs & SACDs.Just as with the other 4 Fosi V3 monoblocks, it is a superb value for money amplifier.

Brings a whole new dimension to the word hifi,

My setup is modest budget-ftiendly kit, I already had an SMSL a300 amp wth the volume turned all the way up and the volume controlled by a cheap passive preamplifier. After lots of research & believing all the hype, decided to 'upgrade' to these Fosi V3 Monos.Admittedly there was loads of detail in the music with them (but no more than with the a300) but whereas the sound with the a300 was full bodied & rich with a big, deep immersive soundstage, the Fosis sounded weak, thin & compressed.I could swap the op amps to try and get a similar sound to the a300 but the pair of these standard units were already £50-ish more than the a300 and 4 decent op amps could be £300-ish (yes you could really do with swapping 4).Save your money and get just one a300 instead, if you really want to try dual mono buy two and put them in bridged mode to turn them into monoblocks, it will still be cheaper than the V3 Monos + decent op amps..If you really want to try op amp rolling a Fosi ZA3 might be the better option, if you buy a single ZA3 and want to swap the op amps you only need to buy 2, if you decide to buy a second ZA3 you can turn them into monoblocks and if you do that you'll only need to swap ONE op amp on each unit so you can take one of the upgraded op amps out of the first ZA3 and put it in the second one, you'll still only need the pair you've already bought - you'll need 4 for the V3 Monos...

Very poor quality control. As soon as I hook a pair of these v3 mono blocks up that they was out of phase,, fosi website had previously put out a statement addressing this issue and assured potential customers this has been corrected since 2nd August 2024 and to buy from them or reputable sellers such as fosi or Amazon. But this is not so.. upon checking the internal wiring as suggested by fosi it's clear to see that one of my amps was indeed wire incorrectly.I also noticed the one amp PCB was dated late 2023 and the other Amp late 2024, the Amp dated 2023 arrived in a box that didn't look new and had what looked like cup rings on the box and the Amp itself was covered in dirty hand prints and binding post had scuff marks indicating previous use, this same Amp start to smell of burning components and in about an hour of been on started to let the magic smoke out, not so magic as these fumes are fairly toxic. I'm had high hopes for these little Amps as they have great reviews in the main, maybe I was one of the unlucky ones, but I wounder how many buyers don't realise the lack of bass and depth is due to the amps being wired out of phase.Pictures to follow.Amazon didn't give a satisfactory conclusion

Good quality, works well.

I replaced my old Rotel power amps for these monos, and they are absolutely fantastic. Running a pair of Monitor Audio Gold Signatures, I had high expectations and they exceeded them.Immense imaging, clarity and a big full bodied sound. Bigger brands should be very worried...Bravo Fosi Audio.

I bought a pair of these micro Mono powerblock amps on the recommendation of numerous online reviews.They do sound great but get worryingly hot after a couple of hours of fairly quiet listening on my KEF R300 speakers.I decided to return them as I was concerned about the heat generated by the amps.