Fosi Audio V3 Amplifier Review

[Yorkshire Mouth]

Would this drive a pair of Revel M16s in a small-medium room (5m x 3m)?

Thanks.

 

[K.Kevin]

Not all class D, mostly the cheaper ones ... but going to the point ... maybe the Aiyima has a greater hf rise than the Fosi with your speakers. That's what I tried to say.
Maybe a measurement in your room can show that (or is another case of "mental trick")

The high frequency load dependency is not what is causing the difference.

Aiyima does have a greater rise, but again, that seems to be mostly at 20khz and above. I highly doubt most people on this forum could even hear that, and even if they could, only those with the best ears could notice a 1db variance from the 0db flat base line.

My ears can only hear up to 14-15khz. Yet I had similar impressions to the Aiyima and Fosi as that other user when it came to high frequency details and clarity.

If it was the rise at 20khz that is causing the issue, then how could I perceive the same symptom if I can’t even hear close to that frequency?

That is what makes me rule that out.

It is something else in the components they use that makes the difference.

 

[mike70]

The high frequency load dependency is not what is causing the difference.

Aiyima does have a greater rise, but again, that seems to be mostly at 20khz and above. I highly doubt most people on this forum could even hear that, and even if they could, only those with the best ears could notice a 1db variance from the 0db flat base line.

My ears can only hear up to 14-15khz. Yet I had similar impressions to the Aiyima and Fosi as that other user when it came to high frequency details and clarity.

If it was the rise at 20khz that is causing the issue, then how could I perceive the same symptom if I can’t even hear close to that frequency?

That is what makes me rule that out.

It is something else in the components they use that makes the difference.

the only parameter i can think is the gain, Aiyima has greater gain from what i remember, so the preamp output / impedance can generate the difference.
that's why leveled gain is a must for comparations ... and preferibly blind listening.

 

[K.Kevin]

the only parameter i can think is the gain, Aiyima has greater gain from what i remember, so the preamp output / impedance can generate the difference.
that's why leveled gain is a must for comparations ... and preferibly blind listening.

The best I could do is use the volume knobs to level-match the SPL using the NIOSH app.

I didn’t do blind listening, but my family confirmed similar results. I was doing instant A/B testing, the left speaker powered by the A07, the right speaker by the V3. Rca from same source, rca left to Aiyima, rca right to fosi. Audio set to mono output, then used the L-R balance setting to switch between left and right speaker to quickly hear an A/B comparison.

 

[K.Kevin]

Thank you. Are those impressions based on the 32V or 48V PSU?

Currently, with the 32V, I agree with your descriptions. That’s also why, for me, the A07 might work better, as my DBR62 are known for being ‘laid back’ and ‘warm’, so the amp might bring more detail in the higher frequencies. (My first impressions also are that A07 is more ‘lively’ than V3, but I’d need to listen again).

The ‘mudiness’ and ‘boominess’ I heard was mainly about using the 48V PSU. It was very apparent, with both amps, with V3 maybe more.

Do you actually listen to any poor sources? I think the potential problem with vents is mainly about 48V and 4Ohm speakers.

* I actually bought the amp for my second, bedroom setup, which has some old, brighter and easier to drive speakers (60W/6 Ohm), but the sound descriptions would be the same.

It was the 32v, I wil need to re-test when I get the 48v psu.

Yes, some sources could be poor. I’m using this for HT to power surround channels. Not all of what I watch is perfect quality. It’s not a massive concern, but it exists.

Similarly, I’m wondering if I probably shouldn’t care that the aiyima sounds better, because maybe I won’t tell the difference in surround speakers. Perhaps what I should value more is the components of the v3 seem to be higher quality, the psu seems slightly sturdier, if it lasts longer maybe that’s the metric I should be considering.

 

[antcollinet]

From my understanding, it also does have it (apparently all class D amps do).

Apologies for the misunderstanding, then. What did you mean?

No, not all class D - or no more so than any other class in the audible range.

Put post filter feedback in it, and pretty much all that load dependency vanishes.

 

[antcollinet]

The best I could do is use the volume knobs to level-match the SPL using the NIOSH app.

I didn’t do blind listening, but my family confirmed similar results. I was doing instant A/B testing, the left speaker powered by the A07, the right speaker by the V3. Rca from same source, rca left to Aiyima, rca right to fosi. Audio set to mono output, then used the L-R balance setting to switch between left and right speaker to quickly hear an A/B comparison.

So the room interaction between the two speakers will be completely different - even if placed right next to each other. That difference will swamp any difference in electrical performance between the two amps. In fact probably the performance difference between the two speakers will be more signfiicant than that between the two amps.

 

[K.Kevin]

So the room interaction between the two speakers will be completely different - even if placed right next to each other. That difference will swamp any difference in electrical performance between the two amps. In fact probably the performance difference between the two speakers will be more signfiicant than that between the two amps.

I don’t want to come across like I’m arguing, and I don’t want this to turn into an argument either

But yes, I put the speakers exactly beside each other to minimize room effects. I also tried another pair of speakers in the living room stereo set up and I had the same impressions. Frankly, I highly doubt room effects are causing the exact same results in both rooms, when they’re placed right next to each other. I think I’ve done enough to reasonably conclude there are genuine differences between the two amps. Like I said, they are very minimal and subtle.

I’m not saying the difference is some magical or mystical reason, I still believe in A S R, measurements, etc. I think there is something in the components or the implementation of the amps that are causing a slight difference. It’s just inconclusive what is causing the difference. Maybe it’s a type of measurement that isn’t in Amir’s reviews

Edit: I’m also aware not to make broad sweeping claims about the A07 and V3 in general, because there could be unit to unit differences in their manufacturing. If I have found there are genuine differences between the individual amps I have, then im just limiting my observations to my sample size. I have some other V3’s on order so I could potentially find out if it extends beyond the units I currently have. But I’m not sure I care enough to spend the time doing it. I’ll consider it, as there’s a million other things on the to do list.

 

[olieb]

I think I’ve done enough to reasonably conclude there are genuine differences between the two amps.

Well, I would not think so.
Unit differences between speakers alone (probably much bigger in effect than those between the two amps) can easily account for those differences, the same can be said for the difference in position (even side by side) and as these comparisons seem to be sighted it is known that this can lead to "hearing" all sorts of differences.
But you hear what you hear. "Genuine differences" are a different story though.

 

[antcollinet]

I don’t want to come across like I’m arguing, and I don’t want this to turn into an argument either

But yes, I put the speakers exactly beside each other to minimize room effects. I also tried another pair of speakers in the living room stereo set up and I had the same impressions. Frankly, I highly doubt room effects are causing the exact same results in both rooms, when they’re placed right next to each other. I think I’ve done enough to reasonably conclude there are genuine differences between the two amps. Like I said, they are very minimal and subtle.

I’m not saying the difference is some magical or mystical reason, I still believe in A S R, measurements, etc. I think there is something in the components or the implementation of the amps that are causing a slight difference. It’s just inconclusive what is causing the difference. Maybe it’s a type of measurement that isn’t in Amir’s reviews

Edit: I’m also aware not to make broad sweeping claims about the A07 and V3 in general, because there could be unit to unit differences in their manufacturing. If I have found there are genuine differences between the individual amps I have, then im just limiting my observations to my sample size. I have some other V3’s on order so I could potentially find out if it extends beyond the units I currently have. But I’m not sure I care enough to spend the time doing it. I’ll consider it, as there’s a million other things on the to do list.

From my point of view it is inconclusive that there is any difference unless when you make the change NOTHING else changes. Not the speaker that is playing, not the postion of the speaker.

Bear in mind even with the speakers side by side, they must be at least positioned 6 inches differently (I don't know the width of your speakers - possibly much more). That is bigger than the half wavelength of everything above 1kHz. Nulls and modes will change throughout the frequency range.

then the speaker on the right will have it's off axis radiation pattern to it's left impacted by the LH speaker - and vice versa.

And the fact you hear the same thing in two different systems, while the tests are sighted, would suggest more to me that biases are at play than that the differences are genuine.

 

[WILL]

Hi guys,
I wanted to know if it would be an upgrade to my system I have a crown XLS 1502 fed by a Topping D90 (non-mqa) and I know the crown is a semi pile of turd (resampling, frequency response shutting down completely above 20k and even a bit before).
Still it has a lot of power and has some very useful features like a simple power button... that the V3 doesnt have.

I go from the topping rca out to my sub (emotiva se12) who does the crossover duty > sub rca out to the crown (and eventually the V3).
My question would be as it will be a pain in the a.. to match the sub gains and the V3 exactly each time would it be ok to put it to max and not allways (most certainly for days in a row sometimes) not turn it off.

PS:Im french sorry if I made some grammar or spelling mistakes

Other amps I might go for Topping PA7 plus, Audiophonics MPA-S250NC (but I dont have the bucks right now)

I have both crown 1502 and Fosi V3 48V.
I tried them on a 12” JBL tower speaker S312ii.
Fosi can’t give low end bass but crown easily present it.
Two amps’ high and mid frequency the same for me.
Now the Fosi V3 is use in my office pair with little bookshelf speaker.
Not really an upgrade form crown.

I am also not good in English.

 

[BDWoody]

I am also not good in English.

Certainly good enough! Please don't worry about that when you are here.

 

[Fleuch]

The "pre-out" on the V3 can be used as an input to another amplifier (V3) in a bi-amping configuration. Similarly the "Aux" output on the Aiyima 07MAX is also, I believe, a feedthrough of the input signal and can be used in the same way.

Moving on to the Fosi ZA3, the "Sub Out" output is derived from two opamps, which, presumably, cannot be used as an input to another ZA3. The obvious answer is to use the V3 for bi-amping and the ZA3 as monoblocks. Are there other solutions using the ZA3??

 

[K.Kevin]

From my point of view it is inconclusive that there is any difference unless when you make the change NOTHING else changes. Not the speaker that is playing, not the postion of the speaker.

Bear in mind even with the speakers side by side, they must be at least positioned 6 inches differently (I don't know the width of your speakers - possibly much more). That is bigger than the half wavelength of everything above 1kHz. Nulls and modes will change throughout the frequency range.

then the speaker on the right will have it's off axis radiation pattern to it's left impacted by the LH speaker - and vice versa.

And the fact you hear the same thing in two different systems, while the tests are sighted, would suggest more to me that biases are at play than that the differences are genuine.

When you say one speaker will have its off axis radiation pattern impacted, that is also the case with the other speaker too. They have been measured on ASR to have symmetrical horizontal radiation patterns. Isn’t that a wash?

I listened from 6 feet away all the way down to 12” away from the speakers. They were placed centrally in the room. Are you suggesting that even when I am 12” away from the speaker, the room effects have overwhelmed my perceptions? Because I can tell you now that even 12” away the “difference” between the higher frequency sound of the two amps were audible.


To clarify, when I say I heard the same thing in both rooms. I mean I heard the same “difference”. I don’t want to suggest that it sounded identical, nor that the rest of the sound as a whole sounded identical either. But that same characteristic came through in both rooms.


I’ll never say it’s impossible for biases to come into play. I find it a bit silly since I dont have any affinity to these cheap amp companies. But I think the more powerful methodological thing to do is get blind testing, which I did with family members. Why is it that they heard the same difference? They certainly didn’t know which amp is which, and frankly, they didn’t even care to know. Even if they saw them they could never tell which is the more premium product. Yet they observed similar “difference”. So if you want to call it down to room modes and speaker to speaker manufacturing differences, I’m fine with that. But if you want to call it a bias, then thats a point I can’t respect (given all I did to mitigate biases)


My last point is so that nobody takes my posts the wrong way: I just want to remind that I still haven’t yielded any final conclusion on what the “better” amp is. That was never the point of my posts. I genuinely dont know which is better to this day. I don’t think one is ever going to be better or worse than the other. I think there’s a multitude of auditory and practical (things like the vents) that can factor into what is a better fit for one’s needs. I think if anyone on ASR wanted to come here and say “amp X is better than Y” they ought to be able to point to an objective measured data to support that. I haven’t pointed to any objective measurements because I haven’t wished to make any finalistic nail-in-coffin claim anything is better than another.

 

[antcollinet]

When you say one speaker will have its off axis radiation pattern impacted, that is also the case with the other speaker too. They have been measured on ASR to have symmetrical horizontal radiation patterns. Isn’t that a wash?

RIght - but each speaker is impacted by the other. So one has it's right hand radiation pattern impacted. The other has the left hand one impacted. So the sound from the two (also with reflections) is potentially different.

Regarding the rest - I've no idea. I'm simply saying that too many things are changing in addition to the amp being changed. I can't tell you that is definitely confounding the results any more than you can tell me that is definitely not. The test lacks suffiicient controls to reach a well founded conclusion.

 

[CauliflowerEars]

Hopefully in two weeks I'll have Fosi family with three V3 amplifiers and make a big comparison!

This sounded interesting. Any follow up?

 

[friedpickles]

The volume of the subwoofer outlet on the fosi v3 is not controllable by the volume knob?

 

[Meloman]

Guys, I don't understand why you need a 48V PSU, Who listens to music with 100W power per channel? 32V 5A is enough. Who says the difference in sound between 32V and 48V I don't hear it.I have Aiyima 07 MAX also, the sound first looks more detailed in highs, but it's far from neutral and natural like Fosi V3, have good headphones that sound like V3 I want to say the sound you can listen to hours but "clear" sound aiyima you want down volume very quickly and aiyima sound very dry. You think overdose highs, but it is not true, you must listen carefully and you understand it.

 

[gcogger]

The volume of the subwoofer outlet on the fosi v3 is not controllable by the volume knob?

No it's not - the phono 'inputs' and stereo jack 'output' are equivalent, and more or less just wired together (OK, each has a 1k resistor in series with it). I'm actually using the 'line out' as an input and the phono sockets as an output.

 

[OldTimer]

Fosi Audio amp + SMSL dac in action. Volume above 2 o’clock no good. Should I use Fosi Q3 pre-amp for this case?
Actually I’m satisfied, it can push the speaker woofer with constant quality vocal.
Notes: 48V-5A psu and bi-wired to Wharfedale 6 ohm floor stand.