Too Hot to Handle! Fosi v3 Mono

The Scientific Audiophile does rudimentary testing of the Fosi v3 MONO amplifier.
‪@fosiaudio‬
#audiophile #amplifier #amp #hifi #hifistereo #hifisystem
Links (Scientific Audiophile is not affiliated and makes NO MONEY):
fosiaudio.com/pages/monoblock...
Music attribution:
Dragon and Toast by Kevin MacLeod is licensed under
a Creative Commons Attribution 4.0 license.
creativecommons.org/licenses/...

[@AndyBHome]

I generally listen to at least 600 hours of Diane Bish before watching any Scientific Audiophile reviews to calibrate my hearing. As usual, my hearing is always perfect and I don't need to change a thing. Unlike normal non-audiophile listeners, my hearing is completely unaffected by emotional, environmental, and physical issues. Everything I hear goes straight to my highly analytical conscious mind, which is why I am such a good person to ask for opinions. I'm completely objective about everything, especially audio. In fact, I have no imagination whatsoever, so it's impossible for me to make mistakes when it comes to listening.

[@scientificaudiophile]

Truer words have never been spoken!

[@iamamadman6542]

Very good point: It should be standard practice to listen to at least 600 hours of Diane Bish before reviewing audio equipment.

[@jimfarrell4635]

I really don't need these, but I know on release day the early bird discounts will be hard to resist, and I have minimal will power. Also these will come in a small box, and I can believably pass them off to my wife as a years supply of vitamins.

[@ReverendDr.Thomas]

Vitamins are MORE expensive. 😂

[@howardskeivys4184]

Get the vitamins. At least with vitamins you know the manufacturer is not being truthful. With audio products you have to discover that for yourself!

[@ricochet243]

⁠@@howardskeivys4184I’d base my opinion on have they been truthful with previous products

[@jimfarrell4635]

@@howardskeivys4184 Very true.

[@chrislj2890]

2:05 "... the stupidity of my mom ..." "Parents aren't like they use to be when I was growing up." There we go, throwing the parents under the bus again, lol.

[@AndiGomez-yu2dx]

They need to be held accountable

[@vvidover]

Awww, yes! Starting the day off right with SA!

[@kennethmajland]

Must admit I bought a Fosi ZA3 to experience what they were talking about. Didn't expect it to surpass my Rega Aethos, but must admit that with lightly driven vintages like the Beovox 1100 or 2200, system matching makes the ZA3 surpass here. Looking forward to hearing the Lowther Bicor 1000 and Zu Audio Cube MKii at class d... With that in mind, I'll have to try the mono V3, with the Aethos as a preamplifier... Work, Consum, Die;)

[@scientificaudiophile]

Well said.

[@edwaux2929]

I was going ro use the za3 as a mono block to run my Polk 12 inch 2 ohm Sub. Now thinking about V3 mono for that and using ZA3 for stereo tops. two amps for 2.1 portable system. Thanks Amir for keeps cool looking jackets alive and well. Maybe there is hope for us after all

[@richh650]

Very glad they added a gain switch... Not sure how they will sound or perform playing anything other than a 1khz sound wave on a reactive load with impedance swings, but interested in your upcoming findings...

[@gage4375]

If your going to get a class d amp,stop playing with these baby amps,get a crown 👑

[@mackenmetal7853]

Interesting insights, but clearly i'm missing some context as I didn't fully get your comment about the Lintons. Can you expand on that, what would be the concerns with pairing the Fosi v3 monos with the lintons?

[@scientificaudiophile]

If you go to the 5 min mark, there is a link in the top right that will take you to the video I’m referring to.

[@stanmyers5994]

Nothing like lunch a beer and Chris!

[@Mizar-XED]

"Valkyries, sound thy trumpets, Zeus, steady thy thunder. Loki, quell thy devious jest, In this arena fires higher than Hades shall burn. This is the real clash of Titans!"

[@stevenkoski228]

You’re the most refreshing reviewer since Greg Weaver😳😂.

[@ForeverAnalog]

I just posted my review and also had a noisy power supply like yours. I pulled two PS from other amps and the noise went away.

[@Douglas_Blake_579]

Absolutely two separate power supplies is the way to go. The entire point of monoblocks is to have two fully isolated amplifiers.

[@scientificaudiophile]

Nice to know. I didn’t have an extra 5 amp ps to try out. Thanks.

[@SERKAN_HOT34]

Gentlemen, I have 2 48 volt 5a like fois audio za3 amplifiers and I connected these amplifiers monoblock, and the muses01,muses02,muses03 opamps play very nicely, and my audio source is my computer with an ASUS X99 DELUXE ll motherboard, and the speaker is Monitor Audio Silver 100 (7G) As a musical style, I listen to rock, blues, pop, latin pop and I'm currently continuing with muses03s. By the way, I buy all my opamps from the original MOUSER and DIGIKEY, and in addition to these, I also bought the original TPA3255DDVR amplifier chips, but I have not changed them yet, but the ones on the amplifier seem to be original, so I am not in a hurry to change them.

[@andreasr6632]

Can those be used with the Wiim Pro Plus or will it require a pre amp for volume control?

[@scientificaudiophile]

WiiM Pro Plus is a preamp with volume control (on the app)

[@AdamMrozek84]

Hello, I really like your videos. You would test pa7 topping. I'm wondering whether to buy topping or Yamaha A-S701. What do you think?

[@scientificaudiophile]

Not on my list right now, but I'd get the Yamaha.

[@AdamMrozek84]

@@scientificaudiophile I've already ordered a Yamaha. Thank you, have a nice day. Kind regards.

[@jfbaquero]

Dear SA for the rest of the world, celsius please!

[@scientificaudiophile]

I should create an online calculator to allow my subscribers to do conversions. Maybe I’ll do the British thing in the future and show both.

[@user-pw7zj8bk8u]

There are free converters available for cell phones and tablets. But that may be too difficult for a "metric-only" type to handle.

[@johnbeaker8721]

​​@@user-pw7zj8bk8uActing like those who use metric are unintelligent compared to Americans (yes they're the only country who still use the unbelievably stupid Fahrenheit) is hilarious. Fahrenheit is an objectively worse unit of measurement for temperature than Celsius.

[@user-pw7zj8bk8u]

A measurement is a measurement. If you don't like it, don't use it.

[@johnbeaker8721]

@@user-pw7zj8bk8u The rest of the world are forced into fahrenheit due to the USs inability to learn Celsius.

[@sensibox]

The heat dissipation design makes the whole chassis into a radiator, which means the surface temperature may seem a bit high. I think that indicates the heat from the TPA3255 amplifier chip is being effectively transferred to the chassis.

[@scientificaudiophile]

You’re right but it is still a burn risk at those temperatures. However, this was a serious stress test and I’m surprised they didn’t go into auto-protection (if they even have that capability). My A-S2100 went auto protection.

[@Douglas_Blake_579]

Heat travels up much more rapidly than down. All the "chassis as radiator" really does is increase the temperature inside the chassis. It does almost nothing to actually get rid of the heat. Moreover, there is virtually no air circulation under those chassis boxes to carry the heat away. So if the tops are hot, the bottom will be much hotter. It's a terrible cooling solution. In fact, you would get a much better result if you turned the amplifiers using it upside down.

[@Douglas_Blake_579]

@@scientificaudiophile Yes the TPA3255 has a full suite of protections built in. Do your homework... search for "TPA3255 Data Sheet" and give it a read.

[@SpirallingOut]

Would you still say the Outlaw Audio 2220 is superior? How's the bass of the V3 Monos with the 48V/10A power supply? Is it lean like some have said of the V3, ZA3 and other Chi-fi mini amps? A slight noise issue isn't a problem for me as I listen to a lot of heavy metal and rock but just out of curiousity, would using a power conditioner do anything to reduce noise?

[@scientificaudiophile]

Yes, 2220 is superior - as it has ZERO load issues, the FOSI v3 Mono still has a slight issue, but only a very few would hear it. I don't know if its lean, the noise issue was a problem - and "heavy metal". Doesn't every Metallica song start off quietly? You would hear it - the noise was apparent when nothing was on. Unfortunately a power conditioner would help because the issue was in the splitter cable itself, not the power supply. They're sending me a fixed splitter cable.

[@SpirallingOut]

@@scientificaudiophile You've got a good point there about the quieter parts of even loud, intentionally distorted music like metal. I listen to a lot of a band called Elder (kind of like a heavier Pink Floyd) and they have long songs with a lot of quiet moments that slowly swell into heavy riffs & drums. If there's a buzz or hum I would probably hear it and it would ruin those songs. Fair enough... I'll still put the 2220's at the top of my list to run a pair of the lower tier Maggie planars and a couple of powered servo subs. Thanks.

[@bjmarchives]

Outlaw is 4x more expensive. They also offer $99 discount if you buy a pair.. but charge $75 for shipping 🤔 so $775 for a pair of 2220.

[@SpirallingOut]

@@bjmarchives I know, but a better quality pair of entry-tier monoblocks is more important to me, even if i have to pay 4x the price of the Fosi it's still affordable if I buy 1 at a time & slowly build up my system gear. They're also more affordable than a pair of Starkrimson monos from Orchard Audio or Tyr from Schiit. At least, for now. But it gives me an upgrade path.

[@treborreissul]

Never seing à worst reviews ever. You do not talking about swapping opamp.Emotiva have the worst mid and high ever listening... And the loudspeaker not have 4 or 8 ohms at all time. Sorry but big bullshit.

[@billdonaldson5714]

Hi. I enjoyed your review, but I still don't understand your comment about the monos not being reccomended for the Lintons. The video link you refered us to goes to your criticisms of the Darko Linton review. I have watched that video twice and cannot find what you are referring to. The link comes up as you mention that the v3 monos can handle reactive loads, and then you state they won't work for the Lintons. Please elaborate further as I must be missing the obvious. If you won't elaborate, I'll have to contact Diane Bish directly!! :)

[@scientificaudiophile]

It's a comment on this video: kzbin.info/www/bejne/iKfKkGWKadiJbc0 where Darko recommended cheap amps to power the Lintons.

[@Berteau76]

Man you are hilarious, enjoy your videos ….you some how made a video about a product you haven’t listened to informative and entertaining..even had some audiophile community drama jokes for fun 😂. Look fwd to video when you get to and running.

[@scientificaudiophile]

I appreciate that!

[@dn2888]

Sorry noob here, appreciate it if you could explain why you said that they wouldn't pair well with the wharfedale lintons?

[@scientificaudiophile]

There’s a link when I say this to another video. That will explain it.

[@StrangeBrewReviews]

The lower power supply 36v version is plenty of power and better noise. Lower heat.

[@Douglas_Blake_579]

And a years longer lifetime.

[@Douglas_Blake_579]

Heat is always going to be a problem with these fully enclosed amplifiers ... even with the fancy little holes on the side. But in fairness running these amps at 3/4 output on noise for hours on end is not a typical operating scenario... it's bench level torture. Most of the time while listening at reasonable levels (75 to 80db spl) you will be asking these little amps for about 2 or 3 watts of power with very short term peaks hitting not much more than 15 or 20 watts. In the normal listening scenario they will not get anywhere near as hot as they did in the noise tests. Probably about 80f or 27c in a comfortable room. Yes, heat is a problem ... but lets not exaggerate it all out of proportion. As always, I recommend that, in these enclosed cases, with smallish heat sinks, you should use no more than 36 volt supplies... so for dual mono, you want 2 x 36 volt 5 amp supplies. That will give you about 75 watts on 8 ohms and 130 on 4. ... more than enough for most scenarios.

[@scientificaudiophile]

Agreed, it is a stress test. One that a hi-end amplifier could pass, so I’m really just trying to see how close they are getting to legitimately replacing those $1,500 boxes.

[@Douglas_Blake_579]

@@scientificaudiophile I can answer that for your very easily .... The TPA3255 chip used in all these mini-amps is actually a pro-audio chip, designed for use in sound reinforcement, studio monitors and AV amplifiers. You're going to find it in some very surprising places, including high end audio products, home theatre, an endless supply of DIY and industry surplus boards and perhaps even in some of the other Class-D amplifiers you've already reviewed. I know of at least one $5,000 "audiophile" amplifier that uses them (but with a far better cooling solution). So the answer is "Yes" these little mini-amps can carry the ball against way more expensive gear... because they're using the same chips. And... FWIW... your V3Ms did pass the test ... you ended the test early, the amps did not die and indeed kept working after.

[@scientificaudiophile]

Correct. They did not die.

[@Douglas_Blake_579]

@@scientificaudiophile So, on to a music test... watch the temperatures... they'll be a lot cooler and you know they can take a pounding. Matter of fact, I destroyed a couple of the 100w gold resistors testing a TPA3255 DIY board... the board lived... the resistors did not.

[@scientificaudiophile]

What did you do with the gold when you were done? I’m hoping make them into jewelry or something. 😀

[@zerospartan]

How do I get a scientific audiophile lapel pin?

[@scientificaudiophile]

I’m working on a store for clothes and mugs, but they don’t have lapel pins. I sent my design to someone on Etsy - a little pricey for one, but I didn’t know I might need more. 😀

[@simonirvine1628]

Did I write that music ?

[@StefaNaja]

please roasting the Topping dx1 cuz many reviewers recommended that thing 😂

[@tonym8358]

Can you compare with Aiyima07 Max on mono?

[@scientificaudiophile]

I don't have the Aiyima any longer, but this FOSI promises a lot more power and little load dependency - at a price premium. I think you can get two Aiyima07 Max for $150 now, so almost 1/2 the price of two Fosi v3 Mono's.

[@pierresternegard6951]

Is there an echo in that room? I think you have a bit of a slapback echo going. Just little more and you'd sound like Elvis

[@scientificaudiophile]

I used two different mic’s in the video. Do you hear it more in a particular scene?

[@simonirvine1628]

I will only raise the noise floor and that's about is mate-E

[@beyondergalactus7308]

Are you guys talking about organ music? 600 hours? I prefer to switch genres, rock, metal, modern jazz, duke ellington, blues. If the recording is good,that’s where the magic happens. I have wiim pro streamer into a geshelli j2 dac with sparkos op amps into a fosi tube preamp with Mullard tubes into a fosi za3 with sparkos op amps into elac unifi 5.2. Huge soundstage! Shocks and amazes my friends! lol…and… I prefer my amps HOT!

[@scientificaudiophile]

Non-organ music is damaging to nearly all audio equipment.

[@korling99]

Can you swap out the opamp?

[@scientificaudiophile]

Yes

[@jimfarrell4635]

Other KZbin types say yes, and I expect you can as Fosi have made a feature of it with their other amps. The problem, as always, will be fitting big discrete op amps like Burson, in the case without drilling holes or buying fancy flexible mounting adaptors and laying them flat, which I would worry could exacerbate the heat issue. I use Burson V6 with my stereo V3 and just drilled twin holes in the top.

[@Eron55555]

Should I buy this on kickstarter or just wait? 100$ to ship?! Surely this will be a better deal on Ali Express.

[@scientificaudiophile]

No idea, I haven’t listened to it because of the noise in the splitter.

[@leetaylor13]

"100$ to ship?" That's in Hong Kong dollars.

[@Eron55555]

@@leetaylor13 Oh that's right. Hmm, I'm tempted but would prefer to have them work out the noise issue before buying.

[@leetaylor13]

@@Eron55555 The rapid rollout of new models does sort of mean early Kickstarter adopters are a bit like late beta testers. On the other hand the discounts are attractive. They promise a fix and say if it's not fixed they can send them out with the 48V 5A supplies. I went for the 48V 5A supplies anyway and have 6 of them coming my way.

[@Eron55555]

@@leetaylor13 Yes, I currently have 2x A07 Max's to my Linton's. I think they are a great match. Not sure what S/A doesn't like about the match to Lintons even after watching his Linton video. Tempted to grab these as the A07 max's replacements.

[@scottlowell493]

Your next upgrade: get a better 100% agave tequila like Cabo reposado. Jose Cuervo (aka Joe Crow) will make you mean like Erin or Amir.

[@larrygaines7462]

Use low gain setting with 4ohm speakers

[@larrygaines7462]

If too hot

[@D1N02]

Why would it get hotter than a V3 stereo with the same chip?

[@scientificaudiophile]

I never tested the v3 stereo for so long at such conditions - a 4 ohm load at 3/4 power is SEVERE!

[@D1N02]

@@scientificaudiophile okay that would be a sound level that would have the police turn up at my door if I didn't blow out the speakers first.

[@tranphuocloc7837]

i think because v3 mono alway at full volume

[@Eron55555]

Wait.. Why is this not for Linton users?

[@scientificaudiophile]

There’s a link in the video when I mention the Lintons.

[@iamamadman6542]

Parents aren't like they used to be when I was growing up. Everything used to be better!

[@Roddy451]

Algorithm... Yamaha sound or Denon sound?

[@scientificaudiophile]

Fosi sound! I may just use that … “Fosi just has a sound”

[@Roddy451]

@@scientificaudiophile 🤣🤣🤣🤣

[@simonirvine1628]

It is good to see that you have sacked that sh*t lighting crew, well done.

[@holbobb6777]

SA, how hot does your reference amplifier get with a 4 hour stress test? You HAVE done that stress test on your reference amplifier haven't you??!!?? Andrew Robinson is watching whilst sounding like a transcendental meditation tape narrator.

[@scientificaudiophile]

I did put my A-S2100 under the same test. After two hours the surface temperature hit 109 degrees into a 4ohm load. It went into auto-protect at 2.5 hours. Never got too hot, but it makes me wonder if there is any auto-protect circuitry in the FOSI.

[@user-bh6my4vq9p]

Nice Fosi commercial. #getpaid #fosicommercial

[@josefserf1926]

I knew it. Its always dad's fault.

[@thinkIndependent2024]

Is listening to white noise like going to a WhiteSnake concert?

[@scientificaudiophile]

Yes, I thought that was implied.

[@10sassafras]

I love how Americans don’t know most of the world uses Celsius. I’m certainly not going to tell them.

[@scientificaudiophile]

I love how most of the world isn’t aware of online conversion tools.🧰

[@10sassafras]

@@scientificaudiophile 🤣 I think the only folks we know for sure aren’t using them is yourselves. You keep publishing the evidence.

[@garrickhanson]

South Americans or North Americans?

[@fonkenful]

Mr Alexander relishes shout outs of his name by You Tube reviewers so much that rumour has it he loses so much sleep each time luxuriating in the adulation that he doesn’t care.fully watch the entire video to parse the context. Of course, after reflection his response is to speed dial his army of dime store litigators to initiate cease and desist orders.

[@scientificaudiophile]

I’m expecting a call from Saul .

[@JordanPhegley]

Eric Alexander 😂

[@scientificaudiophile]

Gotta love a man capable of destroying a company by complaining about a decent review.

[@JordanPhegley]

He's deranged. But he's also a fellow audiophile so what can we expect 😊

[@simonirvine1628]

Sorry have to go, need to catch up on Anglia Railways - Anglia's first privatised Intercity Operator! | Failed Franchises. You take know, bye

[@howardskeivys4184]

I’m no audio technician. But I do have a basic grounding in the sciences, particularly maths and physics. A 5 amp 48 volt power supply can only output 240 watts. So, in order for that thing to manifest 240 watts into 4 ohms, it has to be 100% efficient. Class D amplification is known for being ultra efficient, at least compared to class A or Ab. But 100% efficient, never. Anyways, you described the amp as running hot. Inefficiency, equals heat. Enough said. So now that we’ve unquestionably established that the unit doesn’t live up to the manufacturer’s claims, I’ll be keen to watch your full review, once you’ve been supplied with a non defective power supply. In the world of die hard audiophiles, isn’t separate power supplies with monoblocks a key selling point, or marketing ploy? So, is not a 10 amp shared power supply, a step backwards?

[@scientificaudiophile]

If the splitter can properly send 5amps to each unit, then shared isn’t a problem, but considering my first splitter was a mess, maybe it is a problem.

[@howardskeivys4184]

@@scientificaudiophile a shared power brick, supplying 480 watts is still insufficient to allow 2 mono amps each to produce 240 watts. Unless they’re 100% efficient, which they’re blatantly not, as they get warm.

[@scientificaudiophile]

True. There’s zero chance they can meet 240 watts.

[@howardskeivys4184]

@@scientificaudiophile 👍

[@Douglas_Blake_579]

Okay, here's the thing ... When pumping noise (especially white noise: all frequencies at full amplitude) into a system you are correct. The power brick should rightfully go into either current limiting or a full shutdown. However; unless you are hell bent on making your ears bleed, listening to music at reasonable levels won't even get close to that. With only 10db of dynamic range you are already down to an average of 24 watts... and that will get lower as the DR of the music increases. In most cases listening sessions on reasonable music will give you perfectly adequate levels on 2 or 3 watts, with peaks not likely exceeding 50 watts (for 15db DR). It is a serious mistake to equate a bench level stress test to what a person should expect in normal use.

[@sidesup8286]

First of all, it is an absolute SHOCK that you would find anything wrong with an amplifier company whose products are famous for big orange knobs that maych the color of your suit....Or is it suits, as in duplicates? Fosi...that sounds like a cartoon bear's name. As reported on the news, the bear species has evolved into one that has figured out how to open car doors. It is a BIG MISTAKE to leave a giant jar full of HONEY visibly inside your car. It could even be a bad mistake to leave your keys in the ignition. If they can figure out how to open a car door, who's to say they wouldn't be able to figure out how to turn the ignition key and put their clawed feet on the gas pedal? Real bears, like real amplifiers, can be very different in real life. Orphans, along with certain children who are particularly unlikeable, have the comfort of knowing that even if the whole world seems against them, there are always The Care Bears; who care about them. Although now there's also Drew Carey of the game show The Price Is Right, who at the end of every show, says "I love each and every one of you." So there's two now! Two entities that care about everyone. Drew Carey's last name even has the word "Care" in it, followed by the solitary letter Y. The Care Bears and Drew Carey also care about Diane Bish, so it's not just you that cares about her. Bob Barker for many decades, was the host of The Price Is Right, preceeding Carey. At the end of each show, Barker said something slightly different than "I love you all." He said "Make sure your pets are spayed and neutered." Unless he he meant to look at their undersides to see if they are! He really meant "cut their you know what off." What a terrible thing to do to any being " To take away arguably the most fun thing on the body. And he made it seem so trivial. Like Trivial Pursuit; with suddenly no motivation anymore to pursue another animal of the opposite gender. Neutering is more than just trivial. Don't you as a potential pet owner...Don't you think that NOT neutering, should at least be given some thought? Your pets I'm sure will really appreciate it. Much more than petting them on the head. Your previous Fosi product review read FOSI NEUTERED. An extreme coincidence. But anyway, is controlling the pet population really that big of a problem? When was the last time you saw a stray dog? It's a very rare occurrence. And if you did, when was the last time you saw a stray dog without a collar? I don't know if I ever have. I have always wanted to try dual mono amplifiers. If anything should be neutered, maybe it should be Bears, who have learned how to conveniently open the doors of cars. How far away can it be for Bears driving away in them?

[@crazyprayingmantis5596]

What are you smoking?

[@sidesup8286]

Creativity. As a youngster I learned not to smoke from some very caring companions. The Care Bears care about your lungs and so does Drew Carey. His book is funny, but for adults.

[@Douglas_Blake_579]

Have you even seen the travel folders for reality?

[@sidesup8286]

No time for you, weird one. I enjoy creativity expressed as humor. How about a travel folder to Gaza for yourself?

[@crazyprayingmantis5596]

@@sidesup8286 Maybe you should eat gummies then

[@mikehoward4583]

More bogus crap.

[@landosazo7506]

oh grow up ...my bi-wire speaker cables weigh more than than the amp...poor design,,,they would be too hot too handle if these class D amps can be tweaked to sound like Class A or really fat sounding tube smp...have Elon Musk take a look at it and make it a reality