Fosi Audio V3 Amplifier Review

[antcollinet]

At least in the initial run of V3s, the “pre-out” was in fact a fixed line-level output despite the labeling. this was fixed in the 2024 model V3s with what Fosi called its “enhanced pre-out feature.”

My reply was to someone who has the 2024 model. Hence the reason for my question.

 

[Count Dacula]

I have mine on tiny NAD Q150s for the TV. Only used it a few times, but it's shocking. (pun intended)

 

[Spiky]

In what way is the ZA3 sub out different from the V3 preout?

I want to know this too.
Does it make sense to replace the V3 with the ZA3 just because of the sub output?
Or the V3 preout is sufficient for the sub t.amp final stage.

 

[antcollinet]

Does it make sense to replace the V3 with the ZA3

Not as far as I know. But I've not checked in detail.

 

[sonci99]

I just got this amplifier. I'm not expecting any reference sound, but really the highs are metallic, and not pleasing.
Is there a burning time?
I was using an Arcam Alpha 8, for this system, this amplifier is not a patch for it. Speakers are Quad 11L, 6 ohm impedance.

 

[Joe Smith]

I just got this amplifier. I'm not expecting any reference sound, but really the highs are metallic, and not pleasing.
Is there a burning time?
I was using an Arcam Alpha 8, for this system, this amplifier is not a patch for it. Speakers are Quad 11L, 6 ohm impedance.

Probably not, but give that a try - you can also swap the op-amps, if you have some alternates on hand. Depending on your speakers, the amp does have rise in frequencies above 10k that may be noticeable, if you have good hearing. The new TI chip amps that have recently appeared from Fosi and Aiyima with PFFB have a more linear response.

I can only hear to about 12k, so the V3 sounds fine to me with all the speakers I have tried with it.

 

[antcollinet]

I just got this amplifier. I'm not expecting any reference sound, but really the highs are metallic, and not pleasing.
Is there a burning time?
I was using an Arcam Alpha 8, for this system, this amplifier is not a patch for it. Speakers are Quad 11L, 6 ohm impedance.

No, solid state amps don't burn in.

You might be hearing the load dependency as suggested by @Joe Smith but I think that is pretty unllikely. Another possibilitiy:

Your Arcam Alpha 8 is a 25 year old Amp - it is quite possibly not performing as ti was when new - if it is rolling off the highs and you've become used to that then that may well make the Fosi sound bright by comparison.

Or it might just be that you are listening for a difference so now are hearing one (good old expectation bias)

Give it a week or two of listening to. You may find your ears dial into the sound.

 

[sonci99]

Well, I tried for 2 days, just tizz tizz and no dynamics, not bad for TV duty, maybe it's just my unit.
Old or not the Arcam is totally in different league, and a great deal, considering I bought it nearly for the same price as the Fosi.
I had (probably still have somewhere) an old Topping T amp, and even though it had not a lot of power it was very sweet sounding, highs were never harsh, with good bass too, on high efficient speakers.

 

[ShanSolo]

How is the V3 holding up compared to newer models? I just had a very bad experience with the A07 Max after deciding between the two.

They updated the A07 max to v02 with 63v caps and what looks like Nichicon caps instead of ELNA on the input filtering (pcb mfg 07/24). However the unit I was sent seemed to be a returned/defective unit judging by the damaged box and lack of sticker seal.

Turns out the phase was reversed when connected correctly, it was doing my head in and running Audyssey confirmed it. Connecting + to - and - to + corrects this which means the unit was internally wired wrongly or something.

Looking at the V3 now, it has about 6 watts less with the 32v psu vs the 36v psu the A07 Max comes with, but seems to beat it in all other regards based on Amir's reviews.

 

[Agapit68]

In my experience, the only way to make this amp play is to buy a really good GaN 48v/10a 480w power supply from a competitor and a Fosi DC filter (also 10a). As a result, from an opponent of class D amplifiers, I became their supporter. Before that, my Fosi, bought a year ago (with a 48/5 power supply) was sitting idle, collecting dust.

 

[ShanSolo]

In my experience, the only way to make this amp play is to buy a really good GaN 48v/10a 480w power supply from a competitor and a Fosi DC filter (also 10a). As a result, from an opponent of class D amplifiers, I became their supporter. Before that, my Fosi, bought a year ago (with a 48/5 power supply) was sitting idle, collecting dust.

I think that depends on what you are trying to drive. I'm using this for two 8ohm satellites with 87db sensitivity at 1m from MLP. 34 watts shouldn't be an issue at all even at reference volume.

About the DC filter tho, not sure what that is but will look into it.

 

[sonci99]

In my experience, the only way to make this amp play is to buy a really good GaN 48v/10a 480w power supply from a competitor and a Fosi DC filter (also 10a). As a result, from an opponent of class D amplifiers, I became their supporter. Before that, my Fosi, bought a year ago (with a 48/5 power supply) was sitting idle, collecting dust.

If you mean more power, I think it has plenty enough with this power supply. I also have the 48v supply.

Anyway I found this little guy.

It's a Topping TP20 mk2. I bought it at the time of T amps hype. It still works and sounds fantastic.
When TI TPA3116 got out, everybody was praising for it's superiority to the Tripaths, and probably it is for the bass, but for everything else, midrange, highs, T amps are better.
I don't know the chip inside the Fosi, but I much prefer this Topping, you can listen for hours, the bass is controlled, but you need large woofers to appreciate.
It still has that analytical sound far from the full bodied sound of class AB amplifiers, but at low volumes it's probably the best amplifier you can get.
I thought after all these years new chips would be much better to the TA2020, but maybe they need better implementation.

 

[Agapit68]

Если вы имеете в виду большую мощность, то я думаю, что этого блока питания вполне достаточно. У меня также есть блок питания на 48 В.

Так или иначе, я нашел этого малыша.

View attachment 391560

Это Topping TP20 mk2. Я купил его во время ажиотажа вокруг усилителей T. Он до сих пор работает и звучит фантастически.
Когда вышел TI TPA3116, все хвалили его за превосходство над Tripath, и, вероятно, это касается басов, но во всем остальном, средних и высоких частотах, усилители T лучше.
Я не знаю, какой чип установлен в Fosi, но мне больше нравится этот Topping, его можно слушать часами, басы контролируемые, но чтобы оценить их по достоинству, нужны большие вуферы.
Он по-прежнему обладает аналитическим звучанием, далеким от полновесного звучания усилителей класса AB, но на низкой громкости это, вероятно, лучший усилитель, который вы можете получить.
Я думал, что после всех этих лет новые чипы будут намного лучше TA2020, но, возможно, им нужна лучшая реализация.

 

[Agapit68]

If you mean more power, I think it has plenty enough with this power supply. I also have the 48v supply.

Anyway I found this little guy.

View attachment 391560

It's a Topping TP20 mk2. I bought it at the time of T amps hype. It still works and sounds fantastic.
When TI TPA3116 got out, everybody was praising for it's superiority to the Tripaths, and probably it is for the bass, but for everything else, midrange, highs, T amps are better.
I don't know the chip inside the Fosi, but I much prefer this Topping, you can listen for hours, the bass is controlled, but you need large woofers to appreciate.
It still has that analytical sound far from the full bodied sound of class AB amplifiers, but at low volumes it's probably the best amplifier you can get.
I thought after all these years new chips would be much better to the TA2020, but maybe they need better implementation.

Well, of course I don't mean power. I wasn't happy with the quality of the high frequencies and I solved this problem. I don't see any other way, although there are 90% theorists here who will probably dissuade you from unnecessary expenses.

 

[Karlaka]

Good afternoon, gentlemen.
I come with a question that I think has already been asked in this thread, but if you'll excuse me, I haven't been able to find the answer.
I need to know the input sensitivity of this Fosi V3 stereo (in the ZA3 I think I have read that it is 775 mV).
Can someone provide me with this information? since I have not found it anywhere.
Thank you!
Greetings.

 

[Count Dacula]

I found a pic of mine, so exciting. The Q150s are driven nicely. I think you could do bigger bookshelves with it, like Q350s. Certainly it ups the game for starter systems, allowing people to focus on their speaker budget. Here it's just sound for a big TV in a big room, but it does the job nicely.

 

[BlueDuk]

Anyone try these on magneplanar 0.7 or 1.7’s? Wondering if power was adequate for the 1.7

 

[klirren_65]

Can it be, that the Fosi V3 gets hotter inside with the 48 Volt 5 ampere Power supply, than with the 32 Volt power supply, even if you just use 0.1 Watt (which is realistic with normal music listening) or there is no music playing at all?
I doubt it. With my 48 Volt 5 Ampere power supply, the Fosi stays pretty cool (perhaps 37 degree Celsius).
Did anyone made a propper measurement?

48V 5A I am using - for my taste 37° C on the surface is too much. The August had warm days in Endenich ... on the photo my quick and dirty solution will be seen. 120 x 25 mm 12V running with 7V ... inaudible.

 

[-Jim-]

As I stated earlier

"The standard allowable temperature rise most electronics comply to is 40°C above ambient. Ambient is defined as 20°C. "

I get it that "37° C on the surface is too much" for you, but it's only a 17° C over ambient room temperature with the amplifier off. Like suggested above, put a Fan on it if that'll make you feel better.

Personally, I wouldn't worry about that temperature rise when in normal operation.

 

[TimeGoddess]

I want to use this amplifier with my Kef Q950 speakers. But what I'm worried about is the fact that this amp is not load independent. And the Kef q950 has impedance swings up to 20ohm. Would that make this amp a non starter for these speakers?