We have contacted Erin to send back the unqualified product for analysis and research. We are very grateful to Erin for reviewing our product. We hope that our customers can provide more suggestions to improve our products.
It’s actually a good thing that these get hot. These units use the chassis as a heat sink. They have thermal interface compound the amp chip rejecting heat directly into the chassis through a heat spreader. If the units were cold to the touch, that would mean that the chip is likely overheating due to a poor mount or missing thermal paste. However, it was probably overheating regardless due to torture testing.
Yeah. People often forget that if something sucks back 240W, that’s 240W of heat that has to go somewhere. There’s no active fan blowing air out and letting the heat flow out into the room. But it’s still 240W of heat going into your room, there’s no magical way of getting rid of the heat. As long as the chassis doesn’t get hot enough to burn whatever it’s sitting on and the electronics aren’t frying themselves, it’s doing what it’s supposed to do.
@@martinarrieta4536 if it's outputting 240W at say 90% efficiency that means 24W is lost to heat while the rest goes to the speaker. Now for such a small passive package, 24W is still a lot to dissipate.
@@ErinsAudioCornerwell, there was probably a chance that the atoms would rearange themselves in the right order to make it work again... But you did the mistake to not abide to the laws of conservation of energy. You have to apply energy to the system that was lost in the smoke generating event and then you would have had like a 10^76 chanse to get a working amplifier again. You should try it... 76 aint that big of a number after all. ;)
Okay this is likely to get long... First let me point out that *properly implemented* the TPA3255 chip is a first class amplifier. It ticks all the right boxes for a high fidelity device and as we've seen in ranking reviews it scores right up with the best of them. I know everyone wants the 48 volt supplies so they can suck maximum power from these little amplifiers to feed their 4 inch bookshelf speakers. But that is a mistake, as this and other reviews are showing us. (And I've been explaining for over a year) Heat is a problem; especially in these super tiny mini-amp cases with almost no airflow. We saw it in the original A07, the TB10D, and several others where, if pushed these tiny amplifiers overheat and go into protection on 48 volt supplies. To prevent that you need either a much larger heat sink and forced air cooling or you need to run them at a lower voltage that does not produce so much heat. And before you jump... bolting the chip to the bottom of the case is NOT an adequate solution. That these things get hot enough to burn you, it has to be obvious the case is not radiating the heat away into the air... it is simply getting hot and, trust me, inside that case will be a lot hotter! So, we are left with just one option... turn down the power. In bench testing of these mini-amps, there is a common theme that around 38 to 40 volts, running 1% below clipping, the cooling solution will be overwhelmed and temperatures will begin to rise, more or less out of control. Eventually the amplifier will get so hot that it will go into a thermal panic and shut itself off. This behaviour is exacerbated in the V3Mono amplifier by the "Auto" sensing circuit that will try to turn it right back on while still blistering hot. 40 volt power supplies that will plug into the back of these amps are not commonly available. The closest you're going to get is 36 volts. Thus my recommendation is that you should not run these TPA3255 mini-amps on more than 36 volts. Testing with 36 volt 5 amp supplies these little guys will get warm but not "drop the cup" hot. They will run day in and day out without thermal or current based shutdowns and the odds are they will last a lot longer. ===== A second mistake present in the V3Mono is the sharing of a power supply. The resistance of the DC power leads provides a path through which two (or more) TPA3255 chips may interact in unfavourable ways. When you have multiple chips on a single supply, you are required to provide an external synchronized clock to prevent this. The chip has Master and Slave modes to accommodate this requirement. (Data Sheet page 24) This is not happening when you use the Y connector on the single power supply and a couple of reviewers have reported noise at idle because of it. Although unconfirmed, this problem may be exacerbated by the Post Filter Feed Back networks added to deal with the issue of load dependencies. (That nobody is going to hear anyway) The simple answer here is to use two separate supplies so that no interaction between amplifiers occurs. ===== So what is the best way to set up with these V3Mono amplifiers? 2 V3Mono amplifiers with 2 separate 36 volt, 5 amp supplies. This will give you approximately 75 watts per channel on 8 ohm loads and about 140 on 4 ohm loads... with very low distortion, much less heat, no protection trips and perfectly good sound quality. But most importantly it will last for years instead of weeks.
Other related videos ... th-cam.com/video/wjWVSFCR5MI/w-d-xo.htmlsi=FNPLrOK0t1w22UGg th-cam.com/video/iTLHRXAxwyU/w-d-xo.htmlsi=jw_q-wDIUurCW9v1 th-cam.com/video/2x5v00XYJ6k/w-d-xo.htmlsi=rx_uuAbCBvPaok5d
The mistake with these amps is that they are CHEAP and those are the compromises that had to be made to make them CHEAP. You get what you pay for. Heat dissipating solutions are one of the more costly components of an amp.
Comparisons between tubes and solid state are often audible, because the tube products distort the sound - in ways many listeners find pleasant, yes, but tubes color the sound and so you can hear a difference.
Thanks Erin. I was one of the first to sign up for the kickstarter on this amp because my Pioneer Elite uses a class D amp ( ICE) and my current outboard amp is class AB. I've never tried OpAmp rolling and like the form factor. FYI, you can order the amps with individual 48V/5A power supplies (PS) which I'm glad I did because multiple reviewers have had issues with the 10A PS.
i have a Fosi V3 (2023 version) pushing a pair of Klipsch Heresy II with the preout going to an RSL speedwoofer s10mk2. going directly from my DAC to the V3 sounds adequate, i suppose, but i barely listened to that because I use an Adcom GFP-555II preamp in between them. with that preamp in the loop, I find the V3 to be wholly fulfilling for my purposes.
To get this level of performance you would have to spend twice the amount of money on something like a Yamaha AS-501. However the Yamaha includes a pre-amp, so when you add a preamp to the FOSI it is a pretty good matchup for similar $$$. But we are talking amps here so amp for amp the FOSI gets her don for 1/2 the price.
The Yam is less power at 85w per channel. I think this is around 120 RMS at 8 Ohms which gives you the scope to run most quality towers with ease. I don’t see a down side here?
So, Erin... in the end, did you like how the V3 monos sounded or not? I understand your "no BS" style, but some explanations and/or comparisons would be nice :)
Reminds me of the old audiophile story of the dealer calling up the amp designer and reporting a problem: "The amp is smoking." The manufacturer asks, "What color is the smoke?" These Fosi amps are more of a traditional high-end product than I thought.
It seems like these V3 Mono each need their own power supply to fully function properly. As also shown by Williston Audio Labs TH-cam channel. Look forward to you testing these again with 2 x 5a psu or 2x 10A psu... Also look forward to you ABX testing these (with 2x psu) against your big chunky A or AB amps et... that will be informative.
I have come to really like your channel, a no BS straight forward review process. Good, bad and everything in between. Very refreshing in a world of "this is the game changer, best of I've ever heard" reviewers
I ordered a pair of these, but they're not going on my desk; they're going to my home theater. My AVR has fairly weak amplification but full 7.1 pre-outs, so I'll be using a pair of these to power my main stereo pair. The other five speakers/surrounds will then be powered by the internal amplification. I've been thinking of getting a 3-channel unit but these are so cheap I'm starting with a pair, and if they perform as I expect (there's little chance I'll try to pump 240 watts through them constantly so I really don't expect them to fry) I may add a third for the center. Great deal for amplifiers capable of outputting this amount of raw power with good distortion numbers. I did get the two-power-brick solution, just more flexible than a shared one, and apparently better.
I would love to see Erin do an ABX of a big boy amp vs an inexpensive one like a fosi to see if there's a difference. I once did an AB test of a mcintosh car amp vs a phoenix gold amp and heard a very very subtle lift below 50hz in the mac that made it sound a little more 3D
Erin ... how much time do you spend getting these measurements of yours? Seriously, you're talking about hours ... I can usually get the same data in under 10 minutes.
The Mono version of the V3 is running in BPTL mode and has a second feedback loop behind the output filter (PFFL). TI already published the idea of the second feedback loop when the chip came out (some years ago), but the EVO board did not have it. It might be that the 2nd loop is causing some instability under certain circumstances, which could be why the unit died in your testing. Not many manufacturers use the 2nd loop (only one DIY module, as far as I remember), so maybe others noticed the problem. No idea what happens when the output coil (often too small) reaches the saturation point together with the 2nd loop......
Nice point! And the gain is lowered when pffb is used, the loss of around 6 dB can become a problem in some setups. Therfor a preamp stage has to be implemented. Adds more costs. A fairly good compromise is to setup the output filters for 6-8 ohms, mostly they're set for 4 ohms. But most speakers are more 6-10 ohms in higher frequencies, even so called 4 ohm type speakers.
It just goes to show that there’s very little point in throwing Continuous amounts of money at amplifiers. Just find one that has enough power, measures well, has all the features you need, and be done with it. Instead, just Invest the money into speakers that work best for your room and listening preferences, and maybe look at some room treatment if the wife/ GF allows it 😂
I should have. I was just more curious if I'd hear a difference in this vs their ZA3 since the za3 is load dependent. The March Audio P501 I have is not load dependent so I didn't really have any personal interest in testing that.
I was thinking the same exact thing . Why not abx against the 3050 or better . That would have been way more useful for me personally. Considering the price difference. But hey, at least I now know that there is no difference between a fosi and a fosi
It happened the same to me: purchased two V3 monoblocks with 10A PS, power splitter and DC filter box. Unboxed, connected, they ran just fine for some hours. One of the two smoked not during operation but straight after turning it on and, simultaneosly, hearing crackling noises from the loudspeaker. Raised the case to Fosi Audio.
As i mentioned earlier use laptop cooling fans under them. For the 48volt power supply's. Problem solved. More power. And cool amps. Find laptop cooling pads with very low noise. The pads can be switched on and off as needed. When the temperature gets up to a certain point perhaps one pad will cool 2 amps
Six years in the Navy as an electronics technician and 40 years repairing office machines. I have smelt the horrible smell of electronics burning many times. LOL
Measurements appear to show that PFFB is effective, holding response variation to under 0.5 dB. Do you hear it? Maybe, maybe not, but when you can start from something that is known not to possess an issue, that's always the safer hardware choice.
Here to report that the problem has NOT been fixed, just fried one of mine while listening to music at a normal volume level. Mind you I am using two separate 48V5A power supplies as a few reviewers have recommended. It sounded great for the price, WHILE IT STILL WORKED. I would suggest not buying this model no matter the configuration.
My V3Ms sound great, as in really really good. I was using the P3 as a preamp and couldn’t tell the difference with or without it with the regular V3. With the Monos, removing the P3 cleaned things up noticeably. The only concern I have is the Monos run hot, and one gets hotter than the other making me wonder if the thermal connection to the heatsink is done correctly on the cooler one. I’ll be checking that out before I blow it up, for sure.
I'm not sure I follow - what's the difference between a desktop amp and a main amp? I guess you're saying that folks can use these for smaller applications due to their small form factor but at the same time they do seem to produce 100 watts in fair linearity and with decent inaudible distortion so people could technically use them to power their living room speakers if that's all they can afford and can cool them down. How does my AVR which has the same toroidals as the Marantz SR8015 with more power in benchmarks (not sure why) compare then? Are they not good? Where does capacitance come into this which is what usually expensive amps have more of (100,000 high quality capacitance or 40,000-50,000 for AVRs)?
Hey Erin, just wanted to say thanks for all the great reviews! Been watching for a couple years now and they have really helped me with my home theater purchases. Its rare to see folks use quantifiable data these days. I keep coming back because I didn't realise how interesting it would be to hear people talk about audio math 🤣. I would love to hear your thoughts on "V3 monos little brother" the normal V3.
I don't think Erin is interested in discussing PFFB or any of the tech in this product. Like he said, he is just part of the marketing machine. Push out an interesting video, get the views, increase product exposure. Its a win/win for him & fosi.
Erin always bends-over backwards to be transparent regarding his honest perspective on the equipment. Fosi made themselves look good, responding to negative feedback by trying to fix the problem. I wish more American companies were the same, instead of treating every customer as a one and done.
@@KimmoJaskari My receiver will handle the volume and crossover, I'm guessing these amps will probably be better than the original old plate amp, if they actually have a frequency response down to 20hz, my old sub barely gets down to 25Hz, I'm thinking replace the amp and maybe upgrade the woofer, re-tune the mint condition twin ported cabinet it's all about the bass,
@@dougbulldog9947 Do a little searching in the bigger online vendors. Rather than these tiny, undercooled amplifiers, you can actually get TPA3255 based plate amps ready to mount in a cabinet, and at very reasonable prices.
Just bought 2 to replace a Yamaha A-S501 in a 2.1 system, to which I've just added a Wiim Ultra. I can do all of the sub management and room correction DSP in one controller and let the V3s manage the Elac mains. I'm unlikely to ever get close to using their full rated output, and have a small USB deskfan running to help cooling.
@@adrg-em5qr no. In fact I returned them once I realised I could use the Yamaha as a power amp fed by a Wiim ultra. They're very good, but so is the Yamaha. No need to change, unless the size / form factor was important (it isn't to me)
So it basically fried itself because it got too hot? Am i getting this right? Because that should never happen under normal circumstances as a well-designed amplifier should have protection against that, not just for it's own protection but for the protection of others too, I've seen amps go up in smoke before and I've had some go up myself and it's honestly scary. I can't imagine what would happen if it had caused a fire which is very possible. I've owned a few amps from fosi and they've been pretty good and reliable so far but if this becomes a widespread problem with this particular model they definitely need to address it, an overheating amp should not just simply kill itself and possibly start a fire. It's like saying that a car's engine killed itself because it overheated, the computer inside the car should simply not allow that to happen if it had the proper safety mechanisms in place.
The TPA3255 chip has built in safeties for heat, current, voltage and offsets. The power supply will have overcurrent protection probably for about 8 amps continuous or 10 amps peak. So yes it should have simply turned itself off. BUT it also has the "Auto" mode that will make it try to turn itself right back on due to incoming signal. In the Review by Williston Audio ( th-cam.com/video/2x5v00XYJ6k/w-d-xo.htmlsi=R-JDIsEsgVXXFHEf ) you can actually see it do this in the final segment. Somehow, trying to restart an over heated amplifier strikes me as a seriously bad idea.
@@Douglas_Blake_579 in which situations will there be cases of overheating? can you be more specific? Is it absolutely needed to get lower powered power supply?
@@flyindo The harder you push it the hotter it's going to get. It's not complex. Knowing most "audiophiles" are on a mission to make their ears bleed, I would say the 36 volt supplies are a good idea since they will keep the current and heat within the chip's tolerances without forcing protection shut downs.
@@Douglas_Blake_579 Ok clear, Thx for the explanation. Im thinking of getting these Fosi Audio V3 mono amps in combination of the upcoming Wiim Ultra pre-amp/streamer. I think this will be a good budget hifi setup. Only thing is, will adding a budget external DAC like the SMSL SU-1 or Schiit Modi improve the soundquality? Or should i better yet change the op amps of the Fosi Audio V3 mono amps first to see what that does?
@@flyindo The first thing you want to do is listen to it. Ask the simple (and cheap) question... Is it okay as it is? ... before you go spending bad money after good. Don't go into a new setup with the pre-conceived notion it won't be good enough. Down that rabbit hole lies a lifetime of searching and disappointments. Seriously... if you think it won't be good, buy something else.
For me, these are perfect, but I'm a ludite who believes a really good 2.1 home theater is superior to any number of surround channels. So two of these will be powering my mains once I get them. No volume knob and and auto on/off are critical in a house where i am the only one who knows how the system works.
Id love to get another one to complement the 2 that i bought from their kickstarter. I really wanna see these get used in car audio Class D PFFB TI Amplifiers.
Might have been capable of a little more but 5 amps 48 volts (which is what the separate ones output) is 240 watts on the dot (amps times volts equals watts). It's possible based on these numbers that the joint-10A model is not quite up to the task of driving two, but the 5A are enough for one.
The thing i always want to know with these things are do they have speaker protect and could this be tested, the small form factor is tempting but not at the risk of losing some actually decent speakers which cost 10 times what the amp costs
Do a search for "TPA3255 Data Sheet". All the protections are described there in great detail. The chip has protections for temperature, voltage, offsets and current.
Erin, are you no longer in "cahoots" as it were, with Amir? Or more like an audio "Knight Errant"? I think we're all tilting at proverbial windmills, but "sounds like an amp" is that the sound of one hand clapping, or like what exactly?
@@ErinsAudioCorner Well, Erin, that's not exactly what I meant, not in a necessarily conspiratorial manner, but sorta of an alliance in the spirit of objectivism. I laughingly mentioned way back, "My Klippel's bigger than yours" (don't know how your memory is, you plough thru a lot!) He reference's you in alot of his lists of reviews. How many youtube reviewers besides you him have 100K+ Klippel NFS's? Really hoping that you have (had?) a sense of humor (one of the two things we all need to get thru life) I would like to know what the "Big Bertha" amps that you use to cop a line from one of dearly departed Art Dudley's (old Listener" mag lastly, Absolute Audio) contributors called his system, his "He-Man" rig as opposed to desk top stuff?? My Bona Fides are simple, doing this since '71 in the biz, wholesale/retail and as a "hobbyist" owned tons of stuff
I haven't tested the V3M yet. But other TPA3255 amplifiers in mini-cases operating on 48 volts will end up overheating and going into protection on prolonged loud play. Look for my extended discussion on the heat issue further down these comments.
@@jasonk5979 Yep ... about half the mass it should be and boxed into a closed case where it works more as a heater than a cooler. This new bottom of the case thing is no better.
@@kenandbarbie-b6c That's how most amplifiers are put together. Just not in a small case with the chip mounted in the bottom . I am saying it's inadequate in certain circumstances. Not saying it isn't good value or I am not tempted to try one out. Though I don't need more amplifiers.
I appreciate that you at times seem to come across as over critical. I usually am complaining about reviewers not being critical enough. Especially on the new Chinese brand Amazon like products. Thanks for keeping it real, even if you seemed a bit overly critical on some reviews.
I've seen quite a few comments liking the ZA3 with Lintons. As these share a lot of the same components, they should sound similarly good. Note, I've not heard the Lintons so I'm going off 2nd hand subjective reports here. The ZA3 looks cute under the stands with two PSUs and long pre-power interconnects. These are smaller than the ZA3 so the aesthetics might not work as well.
I have two ZA3's in mono powering my Lintons. As far as subjective opinions go: it sounds excellent. Re. heat: two 48/5 PSU's and they get warm, but absolutely not hot (after multiple hours).
They sell on Amazon and some of the other e-tail sites. On Kickstarter the units are apparently discounted, but it's also straight from Fosi rather than through 3 middle men. They are Chinese or Thai, I forgot which, as you say though.
I think these fosi products would be great in a budget AV Rack. They don't take up much room and they are so inexpensive. Get 3 of these for your LCR and you've realistically got more power than you need. If one dies it's a cheap drop in replacement.
@@Douglas_Blake_579 Sure, but I think it's extremely unlikely that any music, any movie will load the amp as much as these tests no matter the speaker. I wouldn't be too worried, I'd be more worried to connect a DAC that somehow malfunctions and is set to the highest possible volume which could kill most speakers and cause major hearing damage. As Amir also has said on ASR, nothing breaks more than amplifiers, because of high voltages, temperatures etc Most music listening is below 20w
@@Hirnlego999 I'm not disagreeing. Movies and music don't even get close to the torture of general bench testing, especially when amplifiers are driven beyond clipping for hours at a time. However; we do need to wonder why the chip's built in protection circuits didn't shut it down and why the PSU didn't go into current limiting. And we also need to consider the heat issues.
@@mattburgess2 That begs an interesting question ... why didn't it go into protection mode? I've run some horrific tests with these chips ... like pulling 200 watts from them for 8 hours... to see what it takes to kill them. Every time they went into protection and had to cool down before they would play again.
@@Douglas_Blake_579 I'm wondering if that has something to do with the auto on/off function. The listener wouldn't know because the sound is running into resistive loads instead of actual speakers. So to walk away for a few hours the amp probably was going into protect and then turning itself on again, repedivly over and over again. 🤔 It's possible.
Probably not. But, the fox in the henhouse is the "Auto" sensing power on. The supply or the amp might trip into protection but with the input signal still applied it's going to turn itself right back on... while still blistering hot. (That's not good, btw)
Erin, great review! Class D biggest claim to fame is their efficiency and not getting hot so I see it might not be a good idea running several of these in a HT system.
I recently purchased the Fossi Audio bt20a pro for $79 and it was a good value. Driving a pair of Klipsch b20 bookshelf speakers sound is good and loud enough to fill a medium sized room with sound.
A "blind" or unsighted randomized listening test between product "A" vs product "B", where "X" can either be product "A" or "B" via an automated random choice that you cannot control. Having the randomized "X" eliminates being able to "count" or know when you are just switching back & forth between 2 products where the First One you listened to is always "A" and when it switches, it can only switch to "B", and then only switch back to "A"....so you always know which one is "A" or "B" if you keep count.
I have three "big boy" amps that have high current capacity and 125, 100 and 200 wpc. Two of them weigh 70lbs each and the other is much lighter at 30lbs. The oldest one is now 33yrs old and it is my main 2-channel amp. I bought it on sale for $999 in 1991. I know that it won't last forever and class D is probably the future. I was curious about these and checked out the the kickstarter. You can buy these with either two 48v/5a or two 48v/10a power supplies. I ordered two with the 48v/5amp power supplies. I'm just really surprised that Fosi didn't send the 2x 48v/5a version out to reviewers. In my opinion, mono amps should have their own power supplies and not a shared power supply or they're not really mono amps.
The minute I saw that Y cord, I knew there were going to be problems. And you will probably discover your system will be more stable and run cooler on a pair of 36 volt 5 amp supplies.
Erin clearly tested both configurations (single/dual brick) and the single brick performed better. Also in theory there should be less risk of any interference by powering them separately... which in practice probably matters not at all.
Class D are way more efficient than class AB to say nothing of A, but these still produce 240 real watts at decent distortion numbers. That means there's going to be heat. Less heat if you don't push them to the breaking point.
Curious if you opened the fried one. I sent my malfunctioning ZA3 circuit board to Fosi and followed up with them. They actually sent me a picture and explained the problem. Apparently, it was just lacking in the required thermal paste and proper contact with the case. The amp chip is on the underside of the board and it uses the entire case as a big heat sink (why your V3's get so hot I'm sure) and the one that kept shutting off wasn't able to dissipate heat well enough. I bet if you hadn't fried it and did a better job with the thermal paste you wouldn't have had no issues.
We have contacted Erin to send back the unqualified product for analysis and research. We are very grateful to Erin for reviewing our product. We hope that our customers can provide more suggestions to improve our products.
That's a great way to handle it!
These people mean business and deserve our support!!
Awesome way to handle this, Fosi. Makes me want to become a customer.
Make a powerful stereo or mono amp with sub output AND bass management please!
Well said, looking at these to power acoustat x electrostats. Any chance at success?
Don't throw it out, we need an autopsy!
Many ppl know how to solder the amp chip one these, it can be repaired for cheap. Send it to someone willing to fix it :)
Better yet send it back to Fosi for them to improve. They will.
@@TheXJRMAN I'm sure they are watching this closely! I'm really curious to see what failed, since the amp chip has thermal protection...
Send it back to Fosi. Unlike other companies, they want to improve and value constructive criticism.
Probably a VRM
It’s actually a good thing that these get hot. These units use the chassis as a heat sink. They have thermal interface compound the amp chip rejecting heat directly into the chassis through a heat spreader. If the units were cold to the touch, that would mean that the chip is likely overheating due to a poor mount or missing thermal paste. However, it was probably overheating regardless due to torture testing.
Yeah. People often forget that if something sucks back 240W, that’s 240W of heat that has to go somewhere. There’s no active fan blowing air out and letting the heat flow out into the room. But it’s still 240W of heat going into your room, there’s no magical way of getting rid of the heat. As long as the chassis doesn’t get hot enough to burn whatever it’s sitting on and the electronics aren’t frying themselves, it’s doing what it’s supposed to do.
@@martinarrieta4536 if it's outputting 240W at say 90% efficiency that means 24W is lost to heat while the rest goes to the speaker. Now for such a small passive package, 24W is still a lot to dissipate.
@@martinarrieta4536
Nope ... with 240 watts being delivered to a speaker, the chip is wasting less than 20 watts as thermal energy.
"It sounds like an amplifier." damn man, if that isn't the realest thing I've ever heard! Nice review as always man
To me that's a good sign, means it doesn't really have any sound to it, unlike speakers which have a lot more variation
Love your style. I rarely watch youtube reviewers, and when I do, I jump ahead constantly. With your videos, I rarely jump. Well done.
Erin broke one of the biggest Audiophile rules. Never let the smoke out of the product. You must make sure the smoke remains inside the enclosure. 🤣
I just to catch it and put it back in but it didn't work.
@@ErinsAudioCornerwell, there was probably a chance that the atoms would rearange themselves in the right order to make it work again... But you did the mistake to not abide to the laws of conservation of energy. You have to apply energy to the system that was lost in the smoke generating event and then you would have had like a 10^76 chanse to get a working amplifier again.
You should try it... 76 aint that big of a number after all. ;)
Haha yep, Smoke is an essential component of any electronic part: when the smoke escapes, the part stops working.
I hope the Troubadours are not responsible for the Fosi V3 flames.😊
Have we got a hot box situation here?
Okay this is likely to get long...
First let me point out that *properly implemented* the TPA3255 chip is a first class amplifier. It ticks all the right boxes for a high fidelity device and as we've seen in ranking reviews it scores right up with the best of them.
I know everyone wants the 48 volt supplies so they can suck maximum power from these little amplifiers to feed their 4 inch bookshelf speakers. But that is a mistake, as this and other reviews are showing us. (And I've been explaining for over a year)
Heat is a problem; especially in these super tiny mini-amp cases with almost no airflow. We saw it in the original A07, the TB10D, and several others where, if pushed these tiny amplifiers overheat and go into protection on 48 volt supplies. To prevent that you need either a much larger heat sink and forced air cooling or you need to run them at a lower voltage that does not produce so much heat.
And before you jump... bolting the chip to the bottom of the case is NOT an adequate solution. That these things get hot enough to burn you, it has to be obvious the case is not radiating the heat away into the air... it is simply getting hot and, trust me, inside that case will be a lot hotter!
So, we are left with just one option... turn down the power.
In bench testing of these mini-amps, there is a common theme that around 38 to 40 volts, running 1% below clipping, the cooling solution will be overwhelmed and temperatures will begin to rise, more or less out of control. Eventually the amplifier will get so hot that it will go into a thermal panic and shut itself off.
This behaviour is exacerbated in the V3Mono amplifier by the "Auto" sensing circuit that will try to turn it right back on while still blistering hot.
40 volt power supplies that will plug into the back of these amps are not commonly available. The closest you're going to get is 36 volts. Thus my recommendation is that you should not run these TPA3255 mini-amps on more than 36 volts.
Testing with 36 volt 5 amp supplies these little guys will get warm but not "drop the cup" hot. They will run day in and day out without thermal or current based shutdowns and the odds are they will last a lot longer.
=====
A second mistake present in the V3Mono is the sharing of a power supply. The resistance of the DC power leads provides a path through which two (or more) TPA3255 chips may interact in unfavourable ways. When you have multiple chips on a single supply, you are required to provide an external synchronized clock to prevent this. The chip has Master and Slave modes to accommodate this requirement. (Data Sheet page 24)
This is not happening when you use the Y connector on the single power supply and a couple of reviewers have reported noise at idle because of it.
Although unconfirmed, this problem may be exacerbated by the Post Filter Feed Back networks added to deal with the issue of load dependencies. (That nobody is going to hear anyway)
The simple answer here is to use two separate supplies so that no interaction between amplifiers occurs.
=====
So what is the best way to set up with these V3Mono amplifiers?
2 V3Mono amplifiers with 2 separate 36 volt, 5 amp supplies.
This will give you approximately 75 watts per channel on 8 ohm loads and about 140 on 4 ohm loads... with very low distortion, much less heat, no protection trips and perfectly good sound quality. But most importantly it will last for years instead of weeks.
Other related videos ...
th-cam.com/video/wjWVSFCR5MI/w-d-xo.htmlsi=FNPLrOK0t1w22UGg
th-cam.com/video/iTLHRXAxwyU/w-d-xo.htmlsi=jw_q-wDIUurCW9v1
th-cam.com/video/2x5v00XYJ6k/w-d-xo.htmlsi=rx_uuAbCBvPaok5d
@Douglas_Blake_579
Thanks for the analysis and breakdown, Douglas. 👍
In conclusion it’s still a piece of S**T amp and no one should waste their money on any fosi product.
@@bbfoto7248
You're welcome.
The mistake with these amps is that they are CHEAP and those are the compromises that had to be made to make them CHEAP. You get what you pay for. Heat dissipating solutions are one of the more costly components of an amp.
I really appreciated your no BS style! One of the rare youtube reviewers I can truely trust!
I try my best.
They do adapt to reviews and customer comments
Fosi Audio is not a bad actor
Great content as always
Just order two sepetate power supplies
Comparisons between tubes and solid state are often audible, because the tube products distort the sound - in ways many listeners find pleasant, yes, but tubes color the sound and so you can hear a difference.
Thanks Erin. I was one of the first to sign up for the kickstarter on this amp because my Pioneer Elite uses a class D amp ( ICE) and my current outboard amp is class AB. I've never tried OpAmp rolling and like the form factor. FYI, you can order the amps with individual 48V/5A power supplies (PS) which I'm glad I did because multiple reviewers have had issues with the 10A PS.
Best to get 2 x 10 amp supplies with 2 amps.
i have a Fosi V3 (2023 version) pushing a pair of Klipsch Heresy II with the preout going to an RSL speedwoofer s10mk2. going directly from my DAC to the V3 sounds adequate, i suppose, but i barely listened to that because I use an Adcom GFP-555II preamp in between them. with that preamp in the loop, I find the V3 to be wholly fulfilling for my purposes.
To get this level of performance you would have to spend twice the amount of money on something like a Yamaha AS-501. However the Yamaha includes a pre-amp, so when you add a preamp to the FOSI it is a pretty good matchup for similar $$$.
But we are talking amps here so amp for amp the FOSI gets her don for 1/2 the price.
The Yam is less power at 85w per channel.
I think this is around 120 RMS at 8 Ohms which gives you the scope to run most quality towers with ease.
I don’t see a down side here?
So, Erin... in the end, did you like how the V3 monos sounded or not?
I understand your "no BS" style, but some explanations and/or comparisons would be nice :)
Reminds me of the old audiophile story of the dealer calling up the amp designer and reporting a problem: "The amp is smoking." The manufacturer asks, "What color is the smoke?" These Fosi amps are more of a traditional high-end product than I thought.
It seems like these V3 Mono each need their own power supply to fully function properly. As also shown by Williston Audio Labs TH-cam channel. Look forward to you testing these again with 2 x 5a psu or 2x 10A psu... Also look forward to you ABX testing these (with 2x psu) against your big chunky A or AB amps et... that will be informative.
I've seen a few more reviewers have reported that they had one blown as well.
New Record Day is one of them.
Erin, thank you for a great review.
I have come to really like your channel, a no BS straight forward review process. Good, bad and everything in between. Very refreshing in a world of "this is the game changer, best of I've ever heard" reviewers
I ordered a pair of these, but they're not going on my desk; they're going to my home theater. My AVR has fairly weak amplification but full 7.1 pre-outs, so I'll be using a pair of these to power my main stereo pair. The other five speakers/surrounds will then be powered by the internal amplification. I've been thinking of getting a 3-channel unit but these are so cheap I'm starting with a pair, and if they perform as I expect (there's little chance I'll try to pump 240 watts through them constantly so I really don't expect them to fry) I may add a third for the center. Great deal for amplifiers capable of outputting this amount of raw power with good distortion numbers. I did get the two-power-brick solution, just more flexible than a shared one, and apparently better.
I would love to see Erin do an ABX of a big boy amp vs an inexpensive one like a fosi to see if there's a difference. I once did an AB test of a mcintosh car amp vs a phoenix gold amp and heard a very very subtle lift below 50hz in the mac that made it sound a little more 3D
Nice review. I like that you listened to them and shared your measurements.
Erin ... how much time do you spend getting these measurements of yours?
Seriously, you're talking about hours ... I can usually get the same data in under 10 minutes.
Erins Smoke Lounge. Only place with more dangerous 2nd hand smoke than a cigar lounge.
The Mono version of the V3 is running in BPTL mode and has a second feedback loop behind the output filter (PFFL). TI already published the idea of the second feedback loop when the chip came out (some years ago), but the EVO board did not have it. It might be that the 2nd loop is causing some instability under certain circumstances, which could be why the unit died in your testing. Not many manufacturers use the 2nd loop (only one DIY module, as far as I remember), so maybe others noticed the problem. No idea what happens when the output coil (often too small) reaches the saturation point together with the 2nd loop......
Nice point! And the gain is lowered when pffb is used, the loss of around 6 dB can become a problem in some setups. Therfor a preamp stage has to be implemented. Adds more costs. A fairly good compromise is to setup the output filters for 6-8 ohms, mostly they're set for 4 ohms. But most speakers are more 6-10 ohms in higher frequencies, even so called 4 ohm type speakers.
It just goes to show that there’s very little point in throwing Continuous amounts of money at amplifiers. Just find one that has enough power, measures well, has all the features you need, and be done with it. Instead, just Invest the money into speakers that work best for your room and listening preferences, and maybe look at some room treatment if the wife/ GF allows it 😂
Wish you had an ABX against a “big boy” amplifier.
I should have. I was just more curious if I'd hear a difference in this vs their ZA3 since the za3 is load dependent. The March Audio P501 I have is not load dependent so I didn't really have any personal interest in testing that.
I was thinking the same exact thing . Why not abx against the 3050 or better . That would have been way more useful for me personally. Considering the price difference. But hey, at least I now know that there is no difference between a fosi and a fosi
It’s a comparison of a load dependent amp vs another from the same manufacturer. To me that’s more interesting.
That's the review that I want too.
exactly that's what I was expecting too b/c some people considered them "giant killers"
would it be possible to open the burnt one and see what could have happened? output filter caps maybe? thanks
It happened the same to me: purchased two V3 monoblocks with 10A PS, power splitter and DC filter box. Unboxed, connected, they ran just fine for some hours. One of the two smoked not during operation but straight after turning it on and, simultaneosly, hearing crackling noises from the loudspeaker. Raised the case to Fosi Audio.
Thanks for sharing. Appreciate!
Any follow up on this?
As i mentioned earlier use laptop cooling fans under them. For the 48volt power supply's. Problem solved. More power. And cool amps. Find laptop cooling pads with very low noise. The pads can be switched on and off as needed. When the temperature gets up to a certain point perhaps one pad will cool 2 amps
Or fit a small desktop fan for £6 behind them, that will help with case convection as well as air flow through the venting holes.
Six years in the Navy as an electronics technician and 40 years repairing office machines. I have smelt the horrible smell of electronics burning many times. LOL
Measurements appear to show that PFFB is effective, holding response variation to under 0.5 dB. Do you hear it? Maybe, maybe not, but when you can start from something that is known not to possess an issue, that's always the safer hardware choice.
Here to report that the problem has NOT been fixed, just fried one of mine while listening to music at a normal volume level. Mind you I am using two separate 48V5A power supplies as a few reviewers have recommended. It sounded great for the price, WHILE IT STILL WORKED. I would suggest not buying this model no matter the configuration.
Thank you for such an honest review.
My V3Ms sound great, as in really really good. I was using the P3 as a preamp and couldn’t tell the difference with or without it with the regular V3. With the Monos, removing the P3 cleaned things up noticeably.
The only concern I have is the Monos run hot, and one gets hotter than the other making me wonder if the thermal connection to the heatsink is done correctly on the cooler one. I’ll be checking that out before I blow it up, for sure.
I'm not sure I follow - what's the difference between a desktop amp and a main amp? I guess you're saying that folks can use these for smaller applications due to their small form factor but at the same time they do seem to produce 100 watts in fair linearity and with decent inaudible distortion so people could technically use them to power their living room speakers if that's all they can afford and can cool them down.
How does my AVR which has the same toroidals as the Marantz SR8015 with more power in benchmarks (not sure why) compare then? Are they not good?
Where does capacitance come into this which is what usually expensive amps have more of (100,000 high quality capacitance or 40,000-50,000 for AVRs)?
Big power amplifier goes to musical Fidelity. Fosi is amazing for great power in a little package.
Hey Erin, just wanted to say thanks for all the great reviews! Been watching for a couple years now and they have really helped me with my home theater purchases. Its rare to see folks use quantifiable data these days. I keep coming back because I didn't realise how interesting it would be to hear people talk about audio math 🤣. I would love to hear your thoughts on "V3 monos little brother" the normal V3.
They make V3 Mono because of PFFB,and now ,no one can hear difference vs ZA3?
Well they do measure better and will therefor sell better ;)
Correct ... consider that at 80db listening levels the load variance would run between 79.5 and 80.4 db ... a difference nobody could hear.
I don't think Erin is interested in discussing PFFB or any of the tech in this product. Like he said, he is just part of the marketing machine. Push out an interesting video, get the views, increase product exposure. Its a win/win for him & fosi.
And also added a gain switch.
@@34332
By removing the gain control.
Erin always bends-over backwards to be transparent regarding his honest perspective on the equipment. Fosi made themselves look good, responding to negative feedback by trying to fix the problem. I wish more American companies were the same, instead of treating every customer as a one and done.
Erin is becoming FOsi's Quality Analyst! Man, you have to be compensated more :D
I'm wondering how one of these would cope replacing the dodgy 150 watt plate amp on my old 12" Wharfedale Powercube 12+ Subwoofer.
You'd have one issue which was no volume control and no filter adjustments unless you did that externally with something like a MiniDSP 2x4 HD.
@@KimmoJaskari My receiver will handle the volume and crossover, I'm guessing these amps will probably be better than the original old plate amp, if they actually have a frequency response down to 20hz, my old sub barely gets down to 25Hz, I'm thinking replace the amp and maybe upgrade the woofer, re-tune the mint condition twin ported cabinet it's all about the bass,
@@dougbulldog9947
Do a little searching in the bigger online vendors. Rather than these tiny, undercooled amplifiers, you can actually get TPA3255 based plate amps ready to mount in a cabinet, and at very reasonable prices.
audioscience tested the amps at 4ohms got 250 watts that’s at 1 percent thd . at 2 ohms 462 watts same 1 percent thd.
Nice amps to make up an active speaker system.
Just bought 2 to replace a Yamaha A-S501 in a 2.1 system, to which I've just added a Wiim Ultra. I can do all of the sub management and room correction DSP in one controller and let the V3s manage the Elac mains. I'm unlikely to ever get close to using their full rated output, and have a small USB deskfan running to help cooling.
How they compare to your older yamaha amp? Better?
@@adrg-em5qr no. In fact I returned them once I realised I could use the Yamaha as a power amp fed by a Wiim ultra. They're very good, but so is the Yamaha. No need to change, unless the size / form factor was important (it isn't to me)
Most likely the thermistor at the amplifier power input failed... in my Fosi V3 it was the one that smoked...
Any experience/opinions on the Fosi V3 Mono vs. Class A/B options like the Schiit Vidar?
Ho apprezzato molto l'onestà della recensione!!!
Just subbed in - great video/presentation/straight talk. I work a lot with these mini digital chip amps (including Fosi, Nobsound, Douk, etc).
So it basically fried itself because it got too hot? Am i getting this right? Because that should never happen under normal circumstances as a well-designed amplifier should have protection against that, not just for it's own protection but for the protection of others too, I've seen amps go up in smoke before and I've had some go up myself and it's honestly scary. I can't imagine what would happen if it had caused a fire which is very possible.
I've owned a few amps from fosi and they've been pretty good and reliable so far but if this becomes a widespread problem with this particular model they definitely need to address it, an overheating amp should not just simply kill itself and possibly start a fire. It's like saying that a car's engine killed itself because it overheated, the computer inside the car should simply not allow that to happen if it had the proper safety mechanisms in place.
The TPA3255 chip has built in safeties for heat, current, voltage and offsets. The power supply will have overcurrent protection probably for about 8 amps continuous or 10 amps peak.
So yes it should have simply turned itself off.
BUT it also has the "Auto" mode that will make it try to turn itself right back on due to incoming signal. In the Review by Williston Audio ( th-cam.com/video/2x5v00XYJ6k/w-d-xo.htmlsi=R-JDIsEsgVXXFHEf ) you can actually see it do this in the final segment.
Somehow, trying to restart an over heated amplifier strikes me as a seriously bad idea.
@@Douglas_Blake_579 in which situations will there be cases of overheating? can you be more specific? Is it absolutely needed to get lower powered power supply?
@@flyindo
The harder you push it the hotter it's going to get. It's not complex.
Knowing most "audiophiles" are on a mission to make their ears bleed, I would say the 36 volt supplies are a good idea since they will keep the current and heat within the chip's tolerances without forcing protection shut downs.
@@Douglas_Blake_579 Ok clear, Thx for the explanation. Im thinking of getting these Fosi Audio V3 mono amps in combination of the upcoming Wiim Ultra pre-amp/streamer. I think this will be a good budget hifi setup. Only thing is, will adding a budget external DAC like the SMSL SU-1 or Schiit Modi improve the soundquality? Or should i better yet change the op amps of the Fosi Audio V3 mono amps first to see what that does?
@@flyindo
The first thing you want to do is listen to it. Ask the simple (and cheap) question... Is it okay as it is? ... before you go spending bad money after good.
Don't go into a new setup with the pre-conceived notion it won't be good enough. Down that rabbit hole lies a lifetime of searching and disappointments. Seriously... if you think it won't be good, buy something else.
Is there a guideline for speaker sensitivity? Im guessing 90+ is recommended. My 81db efficient speakers would stress them, hard.
For me, these are perfect, but I'm a ludite who believes a really good 2.1 home theater is superior to any number of surround channels. So two of these will be powering my mains once I get them. No volume knob and and auto on/off are critical in a house where i am the only one who knows how the system works.
Anyone know when Fosi will start shipping these out?
good luck with the move. the Klippel going too - you got a place to set it up???
Yes and Yes!
Why did audioscience not have any problems?
A refreshingly thorough and honest review.
Very interesting. Bravo!
Consider yourself subscribed.
Welcome aboard!
I was thinking about getting an audiolab amp for my main system but if it’s ’just an amplifier’….i may as well save £800 and just get the VA3????
Did you test 3a audio 48029a
Id love to get another one to complement the 2 that i bought from their kickstarter. I really wanna see these get used in car audio Class D PFFB TI Amplifiers.
It would have been interesting to see the results of running each amp on a separate 10 amp supply.😊😊
Might have been capable of a little more but 5 amps 48 volts (which is what the separate ones output) is 240 watts on the dot (amps times volts equals watts). It's possible based on these numbers that the joint-10A model is not quite up to the task of driving two, but the 5A are enough for one.
The thing i always want to know with these things are do they have speaker protect and could this be tested, the small form factor is tempting but not at the risk of losing some actually decent speakers which cost 10 times what the amp costs
Do a search for "TPA3255 Data Sheet". All the protections are described there in great detail. The chip has protections for temperature, voltage, offsets and current.
Защита есть в самом чипе
Yes ... they have temperature, current, voltage and short protections built in.
Can you take the cover off the failed amp and see what component died?
The bass quality z3 is match with 2 mono amp ?? My curious
I love the smell of burnt electronics in the morning. It smells like victory. Rock on!
I love your honesty at the start 👍 Sounds like an amplifier 😂
Erin, are you no longer in "cahoots" as it were, with Amir? Or more like an audio "Knight Errant"? I think we're all tilting at proverbial windmills, but "sounds like an amp" is that the sound of one hand clapping, or like what exactly?
I’ve never been in cahoots with Amir. We differ on a lot of things.
@@ErinsAudioCorner Well, Erin, that's not exactly what I meant, not in a necessarily conspiratorial manner, but sorta of an alliance in the spirit of objectivism. I laughingly mentioned way back, "My Klippel's bigger than yours" (don't know how your memory is, you plough thru a lot!) He reference's you in alot of his lists of reviews. How many youtube reviewers besides you him have 100K+ Klippel NFS's? Really hoping that you have (had?) a sense of humor (one of the two things we all need to get thru life) I would like to know what the "Big Bertha" amps that you use to cop a line from one of dearly departed Art Dudley's (old Listener" mag lastly, Absolute Audio) contributors called his system, his "He-Man" rig as opposed to desk top stuff?? My Bona Fides are simple, doing this since '71 in the biz, wholesale/retail and as a "hobbyist" owned tons of stuff
I have read other reviews having issues with the big power supply. I wonder how hot those get just playing loud music for a extended period of time?
I haven't tested the V3M yet. But other TPA3255 amplifiers in mini-cases operating on 48 volts will end up overheating and going into protection on prolonged loud play.
Look for my extended discussion on the heat issue further down these comments.
@@Douglas_Blake_579
Interesting. I have seen these taken apart. Class d or not the heatsink seams inadequate in my opinion.
@@jasonk5979
Yep ... about half the mass it should be and boxed into a closed case where it works more as a heater than a cooler.
This new bottom of the case thing is no better.
The aluminum case is a heat sink as the amp chip is fastened to the aluminum case, with heat sink paste applied.
@@kenandbarbie-b6c
That's how most amplifiers are put together. Just not in a small case with the chip mounted in the bottom . I am saying it's inadequate in certain circumstances. Not saying it isn't good value or I am not tempted to try one out. Though I don't need more amplifiers.
I appreciate that you at times seem to come across as over critical. I usually am complaining about reviewers not being critical enough. Especially on the new Chinese brand Amazon like products. Thanks for keeping it real, even if you seemed a bit overly critical on some reviews.
Does anyone know if these would be good for the Wharfedale Lintons? Or is there something better that you would recommend?
I've seen quite a few comments liking the ZA3 with Lintons. As these share a lot of the same components, they should sound similarly good. Note, I've not heard the Lintons so I'm going off 2nd hand subjective reports here.
The ZA3 looks cute under the stands with two PSUs and long pre-power interconnects. These are smaller than the ZA3 so the aesthetics might not work as well.
I have two ZA3's in mono powering my Lintons. As far as subjective opinions go: it sounds excellent. Re. heat: two 48/5 PSU's and they get warm, but absolutely not hot (after multiple hours).
Got my Lintons hooked to a ZA3 mono block and they benefits very nicely with the increase in power and wattage.
@@34332 Do you think it’s necessary to use ZA3 as monos? Or was one not enough to power it?
@@leetaylor13 Thanks for the helpful info!
Fosi audio is on kickstarter? Aren’t they a faceless chinese company with no public address?
They sell on Amazon and some of the other e-tail sites. On Kickstarter the units are apparently discounted, but it's also straight from Fosi rather than through 3 middle men. They are Chinese or Thai, I forgot which, as you say though.
@@trued2010 Fosi should be able to fund themselves. Wonder if we will see SMSL DACs asking for kickstarter money.
I think these fosi products would be great in a budget AV Rack. They don't take up much room and they are so inexpensive. Get 3 of these for your LCR and you've realistically got more power than you need. If one dies it's a cheap drop in replacement.
No Noise issues splitting the PSU to 2 amps?
Not reported here but other reviewers have reported it.
@@Douglas_Blake_579 Fosi apparently found an error and has corrected it. Still, I'd rather have two PSUs
@@Hirnlego999
The small matter that Erin's sample melted down not withstanding... right.
@@Douglas_Blake_579 Sure, but I think it's extremely unlikely that any music, any movie will load the amp as much as these tests no matter the speaker. I wouldn't be too worried, I'd be more worried to connect a DAC that somehow malfunctions and is set to the highest possible volume which could kill most speakers and cause major hearing damage.
As Amir also has said on ASR, nothing breaks more than amplifiers, because of high voltages, temperatures etc
Most music listening is below 20w
@@Hirnlego999
I'm not disagreeing. Movies and music don't even get close to the torture of general bench testing, especially when amplifiers are driven beyond clipping for hours at a time.
However; we do need to wonder why the chip's built in protection circuits didn't shut it down and why the PSU didn't go into current limiting.
And we also need to consider the heat issues.
I don’t know if I missed it but can you use one of the big power supplies with one amp?
Yes, but not recommended.
Because of the heat problems, I strongly suggest you use 2 x 36 volt 5 amp supplies with these amplifiers.
An don't run test tones through it for 4 hours strait. 😅
@@mattburgess2
That begs an interesting question ... why didn't it go into protection mode?
I've run some horrific tests with these chips ... like pulling 200 watts from them for 8 hours... to see what it takes to kill them. Every time they went into protection and had to cool down before they would play again.
@@Douglas_Blake_579 I'm wondering if that has something to do with the auto on/off function. The listener wouldn't know because the sound is running into resistive loads instead of actual speakers. So to walk away for a few hours the amp probably was going into protect and then turning itself on again, repedivly over and over again. 🤔 It's possible.
@@Douglas_Blake_579 Or is comes down to these new bigger power bricks that split the power between the amps. Maybe something had to do with that.
Wonder if it would not have blown with two 5 amp bricks?
Probably not.
But, the fox in the henhouse is the "Auto" sensing power on. The supply or the amp might trip into protection but with the input signal still applied it's going to turn itself right back on... while still blistering hot.
(That's not good, btw)
@@Douglas_Blake_579 Sp still a risk with two?Maybe the stereo with 10 would rair better
@@charleskatz2606
Simple to check ... turn off the auto sensing and see what happens.
V3 mono how much price?
One would think that a "Power Amp" would have a Crowbar Circuit for Overload/Over Current or even a Thermal Shutdown.
Great test and comments! Many thanks!
Erin, great review! Class D biggest claim to fame is their efficiency and not getting hot so I see it might not be a good idea running several of these in a HT system.
Dont throw the burnt one away. Give it with the working one. I would be ahppy to strip it down and autopsy ti and see how easy it is to repair.
Thanks for the review Erin. Too bad about the smoke. Maybe Fosi will send a replacement.
$500-1000 AB amps are the ones Erin should be ABX'ing.
This is the gear that could be made obsolete by Ti & HYPEX
Fosi seems like a decently large company. Why do they need a kickstarter for this?
Also, you said one of the amps had a 1.5db bump up from 50hz to 500hz but you didn’t mention which amp that was. Which was it?
Dayton HTA-200.
"Seems" and "are" are two different things.
Smokin review there Erin! 😆xx
Be nice box it up, send it back to them.Then they can figure out what kind of damage you did and how do uh prevent it next time
I recently purchased the Fossi Audio bt20a pro for $79 and it was a good value. Driving a pair of Klipsch b20 bookshelf speakers sound is good and loud enough to fill a medium sized room with sound.
Guess they got confused about what people meant by a “warm” amp
Haha. I think it’s me who got confused because I’m the one who tried to make it sound warm with my bench testing. 😂😂
I would love to get my hands on the toasted unit please send it to me. I'll pay for shipping.
I've got dibs on that, sorry.
I want to run it through my test bench and forward recommendations to Fosi.
Excellent review as usual 👍💯👍
Enjoyed this review, thanks a lot.
What can one do to kindly request the one you're giving away? Pay for shipping? Ok. I'm in. Thanks
I have the Cherry amps and they sound wonderful.
So the conclusion is better not buy these or use then with a 32V 5A power sources like I'm using in my TDA7498E class D HIFI cheap amp ;)
Dual 32 volt supplies will work just fine.
I generally recommend 36 volts, 5 amps as a practical maximum.
I wanted to buy a mono but the whole kickstarter thing pushed me away
what is ABX?
A "blind" or unsighted randomized listening test between product "A" vs product "B", where "X" can either be product "A" or "B" via an automated random choice that you cannot control.
Having the randomized "X" eliminates being able to "count" or know when you are just switching back & forth between 2 products where the First One you listened to is always "A" and when it switches, it can only switch to "B", and then only switch back to "A"....so you always know which one is "A" or "B" if you keep count.
@@bbfoto7248 ah ok nice, many thanks. I kmew of the AB thing, the X one lost me. I appreciate your detailed explanation. Blessings
I ordered 2 ZA3's from amazon and one arrived DOA.... 🥴🤷♂
I have three "big boy" amps that have high current capacity and 125, 100 and 200 wpc. Two of them weigh 70lbs each and the other is much lighter at 30lbs. The oldest one is now 33yrs old and it is my main 2-channel amp. I bought it on sale for $999 in 1991. I know that it won't last forever and class D is probably the future. I was curious about these and checked out the the kickstarter. You can buy these with either two 48v/5a or two 48v/10a power supplies. I ordered two with the 48v/5amp power supplies. I'm just really surprised that Fosi didn't send the 2x 48v/5a version out to reviewers. In my opinion, mono amps should have their own power supplies and not a shared power supply or they're not really mono amps.
The minute I saw that Y cord, I knew there were going to be problems.
And you will probably discover your system will be more stable and run cooler on a pair of 36 volt 5 amp supplies.
Erin clearly tested both configurations (single/dual brick) and the single brick performed better. Also in theory there should be less risk of any interference by powering them separately... which in practice probably matters not at all.
@@KimmoJaskari
FWIW ... the amp he killed, died when using the single power supply for both amplifiers.
That was the most unenthusiastic endorsement I think you have given to date 😂
Haha. I hear you. I mean, it makes power and it's small. This stuff just isn't the kind of thing I personally go for.
@@ErinsAudioCorner For sure, and I appreciate the data and insights you provided. I just had a good laugh at this one's conclusion.
He doesn’t want to turn out to be another cheapaudio man
@@veroman007 I hope so! Cheapaudio man is the perfect example of what capitalism does to great youtube channels 😂
@@misterzero8667that’s the dumbest thing I’ve heard in a very long time
Class D amps are not supposed to get hot like this, are they? That's what I thought.
Class D are way more efficient than class AB to say nothing of A, but these still produce 240 real watts at decent distortion numbers. That means there's going to be heat. Less heat if you don't push them to the breaking point.
Curious if you opened the fried one. I sent my malfunctioning ZA3 circuit board to Fosi and followed up with them. They actually sent me a picture and explained the problem. Apparently, it was just lacking in the required thermal paste and proper contact with the case. The amp chip is on the underside of the board and it uses the entire case as a big heat sink (why your V3's get so hot I'm sure) and the one that kept shutting off wasn't able to dissipate heat well enough. I bet if you hadn't fried it and did a better job with the thermal paste you wouldn't have had no issues.