The Fosi V3 Mono Amps are AWESOME (just make sure you buy them correctly)... 

Hi everyone, regarding my power supply issue, Fosi reached out to me with the following note: "We sent you a 48V/10A power supply along with a power splitter cable. However, as this is from the first batch of products, there is a noise issue when using the 48V/10A power supply with two units. We are currently working on solving this issue, and the officially sold products will not have this problem. Please be aware."

Very educational. Thank you!

Great review

Finally , an honest review. There are probably other hidden issues yet to be discovered. I personally would rather pay more to wait a bit making sure there is no more suprise from a brand new product.

Thank U for this video. I also wondered if using only single power supplyer is OK. The other video I watched didn't mention this. I appreciate your trouble.

Great review and good to know about the PSU, I feel like many will struggle with this problem. Now we only need Fosi to make a little handy preamp in the same form factor and design 🤞😁

Great info. Happy to hear I ordered 2 amps with 2 power supply before seeing this. Coming from technology industry redundancy is key. I have spare 5a 48v on hand if one fails so easy call but 10a was a bit tempting. Hope to see how this upgrade is from my V3 stereo.

I think what would be interesting to see is how these type of amplifiers would match up with more expensive solid state or tube preamplifiers. Or how the budget friendly consumer could optimise their sounds quality, matching these amplifiers with other components. I have an Aiyima A07 + muses02 op amp, Smsl SU1 and a DIY Pass Labs Korg Nutube preamplifier powering a Bowers & Wilkins 607s2 and they sound amazing to me. Love your channel btw.

Spot On!!! Great review I hope there is adequate room for a discrete OP Amp upgrade sometimes the NE55XX are sub-par.

really great to know

I will likely get these when the new Wiim Ultra comes out and run the Ultra as my pre amp.

Those switches on the front are something you typically set once and forget. Would have been nicer to have them on the back, but that requires a slightly wider enclosure.

I'm very happy with my ZA3 mono block Linton setup and it doesn't sound like these would be an upgrade. I'd be very interested in a low cost Class D monoblock configuration that would match the 3D soundstage and sound separation of better Class A/B amps as well as 200watts/8ohm per channel.

Planning to buy 3 V3 Monoblocs when I get my 3 KEF R3 Metas later this year, and dedicate my ZA3 + q150s to rear channel. An Emotiva surround processor/preamp should last much longer than a hot/inefficient AV receivers. It'll be an excellent, affordable alternative since there still aren't any Dolby AVs with class D amp topology.

Hi Aaron ... nice review. Absolutely go with dual power supplies. The point of using monoblocks is to have two fully independent amplifiers... connecting them together just defeats the whole idea. As usual, I will suggest that the optimal power supply for TPA3255s in these unvented cases, with limited cooling is 36 volts. So for this I will suggest 2 x 36 volt 5 amp supplies.

Great review, are the sound quality exactly the same between the Fosi V3 mono, vs Fosi Za3 Dual mono ?

I think the joy of these products is the single function and low entry cost, so upgrading to separate PSUs, pre-amp choice, DAC, streamer, Op Amp is all stuff you can lean into gently and affordably as funds allow. Normally this is in the preserve of the $2K + per module in order to play.

Wow thats exactly what i wrote on the comments at cheapaudioman channel. 2 amps feed from 1 power supply is the same like a single amp, that damage the concept of balanced amps. Another thing. That noise sometimes comes from vacuum tubes near some wifi from the streamer, check your equipment setup. Or ground the amps!. I have to mention, i tested 2 V3s to power s biwiring speakers. Was awesome, the image and layering increased. The soundstage not much.

Interesting. Do you think maybe the noise problem originates with the splitter cable?

i was considering "upgrading" from my V3 to these monos, but I'd need 3 as I'd need to feed a subwoofer as well, and overall it just doesn't seem worth the cost. I've got an Adcom GFP-555II preamp feeding my V3, and they sound great to me (feeding Klipsch Heresy II and RSL Speedwoofer 10S mkii).

What kind of loudspeakers do they match the Fosi V3 with. Is it HIFI or just loud sound. Kindly.

@ForeverAnalog did you get to test bi-amping these monos? (Defo NOT bridging) That is the configuration I have gone for. For the ££ involved, it is worth a punt.

Hi thanks for the review. Can you maybe try to connect the 48V 10A power supply to only one of the V3 monos to see whether the noise would be present? To see whether the 2amps per one brick design is somewhat flawed or the power brick is faulty. You are the second reviewer I heard to mention this noise. Thanks.

thanks for the video, I 'm sure that with 32V instead of 48, you'll get less power for sure, but also will gain sound quality, in terms of stage and definition and last but not least, in terms of reliabilty and durability of the components and also way less operating temperatures

I just put my Maggies 0.7 back, now on a pair of ZA3. I marked the spot on the floor with tape yet it took me over an hour to get them to focus in the centre. Only by turning the volume down on the right side I managed to get it centered. First time I had to, but also first time I could in 40 years. I have never had any use for tone controls or balance on my amp. So, how do these sound compared to the ZA3? Does the new feedback design work?

Since we're all about power supplies this time around... lets take a bit of a serious look at what the TPA3255 chip can do... 0:57 ... hit pause and look at the numbers. (Yes they are accurate) For a doubling in SPL you need an increase of 10DB ... 10 times the power. Thus, a 100 watt amp is going to be barely twice as loud as a 10 watt amp. The first noticeable change in SPL will come at 3db... which requires twice as much power. Thus a 20 watt amp is just barely louder than a 10 watt amp, in fact most people would not be able to tell them apart in a listening test. So... between 32 volts and 48 volts ... you have a power ratio of less than 3 to 1 ... That's about an extra 4.5 db of SPL which will be barely noticeable in normal use. Now we know that the TPA3255 can withstand 48 volts... but what is not obvious is that requires forced air cooling and a much larger heatsink if the chip is not going to overheat and go into protection. There have been multiple videos about this with the A07 and the truth is that you cannot continuously cycle the amp into protection without damaging it. The highest power supply these chips can sustain in fully enclosed cases ... even when the case is the heat sink.. is between 36 and 40 volts. They will get warm but they will not shut down into protection and will run continuously for days at a time. Now 40 volt power supplies are not commonly available in "brick" formats, so I generally recommend 36 volts at 5 or 6 amps for these fully enclosed designs. At 36 volts, the RMS power is about 75 watts per channel on 8 ohms and 130 on 4. I've done some bench testing on TPA3255 amps (although not the V3M version) and while the power is lower at 36 volts, the distortion, frequency response and other parameters are quite stable... in fact there is no sonic advantage in feeding it 48 volts. Consider that most reasonable listening is going to happen in the 75 to 80 db spl range. For most speakers that will require about 1 or 2 watts... yes, power in single digits. Short term musical peaks, based on curated 16 lufs of overhead from most streaming companies will hit about 30 watts. Thus you can likely play your music collections quite loudly without ever using up the amplifier. If you consider the barely noticeable difference in SPL, the stable sound parameters, cooler operation and longer lifetime... There is literally no reason anyone should want the maximum voltage here... and especially not at the risk of drastically shortening the amplifiers lifetime. Aaron's setup with 2 x 32 volt 5 amp supplies will have them running cooler, with only a slight difference in SPL but otherwise still delivering their best sound. For this V3 mono ... I would recommend two amplifiers and two 36 volt 5 amp supplies as the best setup.

What would you recommend as a Pre-amp with volume control for a Turntable setup?

Hi, thanks for the review, I'm curious how it sounds compared to the Aiyima A07 MAX, none youtuber that got both did a comparaison between them. I've only heard that the Ayima 07 Max is wider soundstaging and more clear and bright than the Fosi ZA3 but it's the same conclusion i hear about the ZA3 compared to the V3 Mono, so how is this V3 mono compared to the A07 Max, did someone test it switching from one to the other?

Just when your video said you’re going to let us hear what the noise sounded like, it went to a JBL Authentics commercial. I’m listening intently for 30 seconds waiting for the noise until your video started again. 😂

I going for the two power supplies preorder but is 5A sufficient for the amplifier? Or will the 10A be better? I haven’t seen anything about max current draw related to max power output. Thanks for the review I was thinking about this question before ordering and you answered it.

Thanks for review What preamp and what speakers you recommend for these ? Would you recommend two blocks of 5 A each or 10 A each?

привет, а если у меня есть bluetooth плата с ldac и регулятором громкости, выходами rca и недорогими колонками, то имеет ли смылс покупать v3 моно или можно купить обычный v3 ? будет ли слышна разница в звуке?

I got 2 x V3 Fosi amps with 2 x 48V PSU and bingo - great sound. The pricing on the Kickstarted is a little high. Go get 2 V3's second hand and save the money. If you do bu the new ones, I suspect the price will not be attractive when you add into the extra PSU (that you really should have).

Get them with 36v power supply each...lower noise ,plenty power and runs cooler.

Great review, thank you. What do you think about the idea of replacing 2 x Freya mono (XLR) with 4 x V3 mono (5A) (via XLR Y split)?

Which op amp(s) do you advise to add a little warmth/smoothness, improved soundstage, little bit more emphasis on reverb to the sound without losing clarity/fidelity/details?

It may be stupid question. I have Wiim Amp. Can i use this Fosi V3 mono connecting to Wiim Amp?

The gain boost looks like it is only applicable to the rca inputs. Other reviewers haven't experienced your issue with the power supply. It is probably an issue with the supply itself. I wouldn't give advice on this before consulting with Fosi about it. For me I would probably go for separate supplies to keep the speaker cables as short as possible. Then I would probably get the GanFet 48v/5a supplies fosi also offers.

Did the noise disappear when you powered on the other V3 mono?

Not getting the set with the one power supply. Not just for the noise, but also the reduced possibilities of placement

Would you recommend buying two of the 32V or two of the 48V? Great video by the way!

How come Fosi doesn’t make a matching preamp for those mono amps?

I'm going to take Aaron's word about the sound quality. I'm sure it's pretty good. However; I'm still not convinced this bottom chassis cooling thing is a good idea. There have been several reports of high temperatures and heat. (Flip them over upside down.. do they run cooler?) I'm also not sold on the "full bore' design with no attenuators to level match and/or set maximum sound levels. I still don't get why the XLR/RCA switch is needed on the front when there are relatively simple auto-selecting designs that could be incorporated for only a few pennies more. I really wish these manufacturers would implement the Clipping and Protection warning signals provided by the TPA3255 chip to help people keep their listening sessions within the clean audio capabilities of the amplifier. Why didn't they continue the 12v trigger from the ZA3 in this new model. Using a trigger out on a pre-amp or with a simple hub they could control two of the monoblocks and 2 powered subs from a single switch. === I've been watching all these various iterations of TPA3255 designs from several manufacturers. All of them seem to get it right... _except_ ... and there's always that near miss _except_ . I won't pretend to understand why but if the designers sat back and looked at what it takes to run a comprehensive system, one might reasonably assume they could figure it out.

There looks to be two opamps for the amplifier in this so is this a true mono or did fosi just shut down one channel like the za3? That doesn't make it a true mono amp right?

I commented about the heat issue but the post seems to have disappeared.😡 Once again...I have no problem running the ZA3 with 48V 5A and 10A PSUs. It barely gets warm, a far cry from some Class A amps I've owned and cooler that the 5V LPSU I use to power my Raspberry Pi/Allo DigiOne sig streamer. I haven't tried listening at eviction notice levels for 12 hrs in the middle of a heat wave but still... If ever I found it getting too hot I would modify a computer fan to run slow/silent off a 5V USB connection and place behind the amp to draw hot air away from it. But honestly I can't see that happening.

Yes, it has an XLR connector, but is that input truly/fully balanced?

Is it possible to connect the 48v 10a to each mono?

The TPA3255 class D amplifier chip has a 53.5 maximum working voltage and in my opinion running them at 48 V with a minimal heatsink (that case) is not a good idea, somewhere around 40 V would be better for long term reliability.

My only issue with the za3 is there is a dip in the lower mid range. For example, Alice n chains got me wrong live, lane Staleys voice is not as loud as Jerry Cantrells voice. On that recording they occupy the same space. Plus the beautiful crunchy accoustic guitar is recessed. My fear is the mono blocks will be voiced the same way.

New subscriber here. I've been looking at the Ayune Flamingo to use as a preamp with these. I think you reviewed it, didn't you? Either that, or maybe a Bottlehead DIY preamp. What do you think?

Does anyone know when Fosi is going to start shipping these out? I ordered 2 and I'm dying to try them out! Also, I'm planning on using the v3 to power Martin Logan electrostatic ESL speakers (one v3 for each). Do you think these amps will power the electrostatics enough/sound good? Id love to hear everyone's thoughts!

Legit question, how does a two channel amp work with a single power supply and not have the noise issue? Isn’t a two channel amp just two monos in a single chassis?

Just received the 48V 10A PSU for the ZA3. My initial impressions compared to the 48V 5A version are that it sounds more detailed, better separation but possibly a bit thinner sounding. I switched back and forth a dozen times on different tracks and then let the 10A in for a few hours listening to random tracks. Could be fatigue or my state of mind so I'll need to give it another go tomorrow with rested ears. I was quite happy with the 5A version but decide to order the 10A somewhat out of curiosity but also hoping that it would have more headroom for difficult to drive speakers.

Another advantage of two power supplies would be more power. 😁

Lots of YTers releasing videos on this product today. Would love to watch an honest video on why that is.

So what is the price for two of the amplifiers with two 48 volt volt 10 amp power supplies ?

How about the monoprice amp that has a real 90wpc measured 20-20khz. not just 1khz? Class a/b, no need for extra power supply or opamp changes.

If it seems too good to be true it usually is.

I wonder what will sound better? V3 Monos with a 5A PSU per amp or 10A PSU per amp?

Doesn’t he have a very high sensitive speakers? Might not be a problem on another set of speakers.

How much does one cost?

I'm sure these sound great. It's too bad about the power supply.The British Audiophile rated the original V3 as the best amp under 1000 pounds. He is British after all. Great info. Thanks for the heads up.

Doesn’t look like plenty of venting.

Like it except there was a no crossover bypass for the subwoofer output.

I saw most of reviews, this review is less stellar in fact below average I think you have a retake review, no indepth comparison with V3 integrated.

It seems other reviews haven't had the same problem as you.

Did you test each independently with the included power supply? I don't think a single power supply would be an inherent problem. If the noise continues with the included PS when it's only hooked up to one amp, it's the power supply or amplifier, NOT the fact that they're both hooked up to the same power supply. You've also got a problem if you hook up separate power supplies that don't test the same in voltage and amperage. There's no likelihood that they do even if they're both spec'd the same, thus one amp may be 80 watts and the other could be 90 watts, etc. More info is needed.

When buying a set of monoblocks with a common powersupply, you have a stereoamplifier In two cabinets - why wold anyone want that? More interesting is, why Fosi does not put the powersupply into the cabinet and make it themselves - that would give them a few more controlpoints and avoiding the powerconnector that needs to carry a lot of amperes.

The Chinese power amps need to list RMS power rating instead of peak power rating.

you know....as much as I like these mini amps, the power supplies are highly questionable and likely the main problem with them. I have a za3 with the 48v/5a supply and I don't get noise through my system, but the connection between the brick and the power plug end of the cable comes apart way too easily, and sometimes even when everything is connected "tightly", the PS makes a bizarre whining noise. have to unplug it, let it sit for 10 minutes or so, and reconnect it to the mains to stop the noise. It's not encouraging and there is no way in hell I'd leave this thing on and unattended. Just shady.

Can anyone name any mainstream speaker company besides Tekton that offers 2 ohm stereo speakers (non PA or Car audio)?

You didn't run them in balance ? They are balanced by design And cancel noise. ? Also separate power supplys is the way to go ! If this was designed with XLRs those are primary and RCAs are second by design. If you hook it up balance and still have noise then something else is wrong .

Just give me a true balanced monoblock. I dont care about power supply. There are tons of options for this.

The V3 manufacturer is making inaccurate claims. Claiming each V3 mono amp can deliver 240 watts into 4 ohms. They supply either a shared 480 watt power brick, or 2 240 watt power bricks. This means that in order for those V3 mono amps to deliver that level of power, they must be 100% efficient. They’re not. They get warm. That warmth is generated by electrical inefficiency. Begs the question, what other inaccuracies are hidden with in?

I'm confused as to why anyone would want these things. Between the two amps and the power brick it doesn't save much space over a traditional amplifier, plus you have the mess of wires that comes with it. And for the price (probably $300 retail after the Kickstarter is over) you can get an entry level (new) Sony, Yamaha, or Onkyo stereo receiver. And if you're willing to buy used, there's a ton of cool stuff that blows these things away for the price. So...I just don't get it.

It's maybe a good amp, but doesn't worth its price. Buying a TPA3255 amp with $140 is insane. TPA3255 module only worth $15. Then the case worths over $100? What so called PFFB is just a few caps and resistors suggested in the TI datasheet.

I don't understand how a company can sell a product with such glaring flaws.

get two psus, problem solved

There are already Soooo many amps the world don't need another amp🤢

中国人骨子里的：多快好省 大干快上 差不多得了

If you would stop promoting and evaluating this Chinese crap , maybe they would go away and people will start buying products that will hold up over time from reputable companies.

Very informative now cut that ridiculous hair

W T H. DID this company tell everyone to come out od the wood work and say nice crap about the damn China stuff. OK course you want say anything about switching powee supply Not knowing to much. A have a lot of Class D. Amps My Polish friend. I suggest you should buy them. Who are you ???

Low fi

Typical " cut corner type" of the Cheap Chinacom amps.