Fosi Audio V3 Amplifier Review

[dr_mick51]

I have an Fosi Audio V3 on the way. I also have other "ChiFi" products, so my intent is not to engage in political arguments here.

What I do know for certain is that tested units have components that appear different than beauty shots by Fosi and that there are those who maintain that fact proves or at least brings into question the authenticity of parts.

I have reached out to Fosi Audio with a question about the authenticity of the Op Amp used in the V3. So far, no reply. I will certainly post if/when I hear from them.

Leaving the whole "is it OK to use counterfeit parts?" argument for others- the primary issue for me here is one of trust:

Can I be confident that the manufacturer used genuine parts as claimed?

Will my V3 have the same parts as those units that were so positively reviewed on multiple sites?

Will my V3 measure and sound the same as those units reviewed?

Why hasn't Fosi Audio weighed in on this issue as it appears the company follows this forum?

Dude. I feel you. But you are missing the whole point. We all know how marketing and commercials work, they always lie or exaggerate. For this amplifier to sell at this price they cannot spend more than $30 in parts. You need to understand that components are expensive, even if bought in bulk. Enclosure is expensive, power supply alone is 10-15 dollars. It does not leave too much for internal parts: pcb, chipset, capacitors, voltage regulators, inductors, connectors...
Would you be happier if they used 100% genuine parts, charged you $200-$220 and get this kind of performance?.

At this price point and getting this performance I don't understand how everybody is not celebrating instead of complaining.

 

[dr_mick51]

What if the OPA2134PA is as fake as the one that's in it when it's delivered?

You are right. LOL.

 

[dr_mick51]

Great Review!

Regarding Op-amp "Rolling": I wonder if the audience could answer my questions:

1) I guess these OP-AMPS are in the signals path before the class-D amplifier chip.
Does anyone have a rough schematic of this? Wanted to understand what these
amps are doing exactly.

2) What Op-Amp specs matter? Is it just noise and distortion, or are there any other parameters?
Otherwise I wouldn't know what's a good Op-Amp to replace the default ones with.
Should be a purely technical question IMO.

3) Which OP-Amps does the Fosi V3 come with?

Thanks much for any inputs.

Yes. As already mentioned opamps are on the signal path. The TPA3255 is a differential amplifier chipset, but this amp (the applies to the the Aiyima A07, and the two other Fosi amps) has single ended (RCA) inputs. The opamps used on these amplifiers are dual opamps. This means internally there are two opamps( for a total of 4, 2 for each channel). Therefore the opamp has 2 functions: one, it acts as a buffer with approximately unity gain(this is done by the first stage on each Op-Amp). Two, it created an inverted signal of the output of the first stage. This produces the differential inputs for the chipset.

What opamps specs matter?. All of them: operating voltage, noise, distortion, slew rate, bandwidth , power supply noise rejection, common mode noise rejection, gain, current.

The Fosi V3 comes with 2 "NE5532" which seems to be fake. But they can be replaced.

An opamp is a small voltage or signal amplifier. But depending on how is implemented it can do multiple things like signal inversion, low or high pass frequency filter, etc..
On this amplifier is mostly used to invert the input signal.
On the other Fosi amp with EQ, two extra dual opamps are used. One for lows and the other for highs control.

 

[totti1965]

Ok let’s crack ‘‘em all open and see what shakes out starting with Topping LA90 … who’s dri on this?

www.Audiophonics.fr did.

 

[fishmorganhammond]

Dude. I feel you. But you are missing the whole point. We all know how marketing and commercials work, they always lie or exaggerate. For this amplifier to sell at this price they cannot spend more than $30 in parts. You need to understand that components are expensive, even if bought in bulk. Enclosure is expensive, power supply alone is 10-15 dollars. It does not leave too much for internal parts: pcb, chipset, capacitors, voltage regulators, inductors, connectors...
Would you be happier if they used 100% genuine parts, charged you $200-$220 and get this kind of performance?.

At this price point and getting this performance I don't understand how everybody is not celebrating instead of complaining.

I believe it is possible to both complain (criticize) and celebrate at the same time. Not getting what is promised is most certainly deserving of criticism.

Above average performance at any price point is worthy of celebrating. I hope that is the case. When I receive my V3 and listen to it I hope to be able to celebrate its performance.

Come to think of it- both celebrating and criticizing are fundamental and necessary parts of reviews, are they not?

Finally, one can call me naive, but I don't believe everyone lies or exaggerates in marketing and commercials. That said, I did appreciate the reply.

 

[dr_mick51]

www.Audiophonics.fr did.

That's a heck of an amplifier. Someday....someday.

With that performance, I really don't care what's inside. LOL.

 

[sarumbear]

You could guide me (and many others) to some references how it works. Perhaps with some images to go. I fully appreciate that things are not always as they seem but asking why would I understand is not very fruitful.

I wouldn’t know as I’m not qualified. I won’t be surprised if nobody on ASR is either.

You're saying that we can't be sure by looking or by measuring. So there is no way to know what is real/licenced and what is not? Perhaps, I have no problem with the general idea. But why would I take your word for it?

Because I know enough of the process to know that it’s not something an audio hobbyist can know or understand. What makes you think that you can understand a highly specialist process of IC manufacturing in order to comment on it?

 

[mccririck]

Just did the same order from the UK. Total 98 GBP with free shipping

Where did you order from? I'm in UK too.

 

[Verig]

Because I know enough of the process to know that it’s not something an audio hobbyist can know or understand. What makes you think that you can understand a highly specialist process of IC manufacturing in order to comment on it?

I do have other interests in this life beyond an audio hobby.
Seeing that you can only buy guaranteed TI parts (outside of Japan) from four places it does not really sound like licencing to anyone and deviating from specs is the norm here.

 

[alvigg]

I have installed 3 of these. All are significant better than my Parasound V3 and 273 amps. The first one to arrive was a 32V version which was a little power starved for a big room but now I have a 48 V version there and the 32 V version in my bedroom. A cheap improvement.

As I get older, replacing heavier amps with Class D ones has both improved sound and made it more likely I can continue to move them!

 

[sarumbear]

I do have other interests in this life beyond an audio hobby.
Seeing that you can only buy guaranteed TI parts (outside of Japan) from four places it does not really sound like licencing to anyone and deviating from specs is the norm here.

What is a guaranteed TI part? Do you mean a company that sells $5bn worth of parts have just four distributors?

 

[strawberry644]

When I first got my A07, i fell down the opamp rabbithole. there is also much talk about the NE5532 being fake also and i ended up going to OPA1656 on DIP8 sockets im not a expert but i feel it sounded better with my ELAC debut b6.2 and the 48v 7.5amp power supply. (today just got the fosi v3 and using it with the same opamps 48v psu, and the same speakers, I will update when I feel Ive spent some time with it)
https://www.ti.com/lit/ds/symlink/o...=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA1656

What I wanted to contribute is in my research (again no expert) but on the data sheets of the NE5532

https://www.ti.com/lit/ds/symlink/ne5532.pdf?ts=1687606290203&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FNE5532

the original date of this opamp has been around since nov. 1979, in my personal opinion the NE5532 is well documented and very old. for a chip that costs around 5cents I doubt Id be splitting hairs between who made it .

Another thing I would like to note is when opening the fosi v3 I bought, the thermal paste they used under the heatsink basically looked like water replaced that with some I had on hand right away, wondering if that could be some of the heat problems others mentioned. I noticed the same on my A07 all of it was pushed out away from the metal core heatsink that's a part of the 3255 chip.

 

[gad]

go go go go Godzilla

Like Godzilla Fosi absorbs energy and rapidly mutates into fiercer beasts. Maybe Fosi will evolve into the "DISRUPTOR"; an audio Godzilla toppling Goliath scam audio skyscrapers with SOTA cheap high watt amps. Fosi, if your reading this, please let the next generation, you know like next week, be the $100 end game.

 

[dr_mick51]

When I first got my A07, i fell down the opamp rabbithole. there is also much talk about the NE5532 being fake also and i ended up going to OPA1656 on DIP8 sockets im not a expert but i feel it sounded better with my ELAC debut b6.2 and the 48v 7.5amp power supply. (today just got the fosi v3 and using it with the same opamps 48v psu, and the same speakers, I will update when I feel Ive spent some time with it)
https://www.ti.com/lit/ds/symlink/opa1656.pdf?ts=1687610336684&ref_url=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA1656

What I wanted to contribute is in my research (again no expert) but on the data sheets of the NE5532

https://www.ti.com/lit/ds/symlink/ne5532.pdf?ts=1687606290203&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FNE5532

the original date of this opamp has been around since nov. 1979, in my personal opinion the NE5532 is well documented and very old. for a chip that costs around 5cents I doubt Id be splitting hairs between who made it .

Another thing I would like to note is when opening the fosi v3 I bought, the thermal paste they used under the heatsink basically looked like water replaced that with some I had on hand right away, wondering if that could be some of the heat problems others mentioned. I noticed the same on my A07 all of it was pushed out away from the metal core heatsink that's a part of the 3255 chip.

Yes, exactly the same opamps I'm using, but they require the adapters and soldering, which might seems daunting for many. $12 plus adapters $5. If I remember correctly.
Or the LME49720 which are a cleaner version of the NE5532(very old), faster and lower distortion. And they don't require adapters. And also very cheap, $3-$4 each.
You need to understand that technology advances every day. The NE5532 was for a long time the best bang for your buck. But not anymore. The OPA1656 is the new king. It's a shame that because of modern miniaturization of pbc and surface mounted devices as a trend, it does not come in DIP8 package.
There are very pricey discrete opamps option like the Burson and Sparkos but very overkill. I don't deny they sound better than the fake stock opamps(probably any modern opamp does). But you might not hear any difference compared to cheap modern opams as previously mentioned.

 

[strawberry644]

Yes, exactly the same opamps I'm using, but they require the adapters and soldering, which might seems daunting for many. $12 plus adapters $5. If I remember correctly.
Or the LME49720 which are a cleaner version of the NE5532(very old), faster and lower distortion. And they don't require adapters. And also very cheap, $3-$4 each.
You need to understand that technology advances every day. The NE5532 was for a long time the best bang for your buck. But not anymore. The OPA1656 is the new king. It's a shame that because of modern miniaturization of pbc and surface mounted devices as a trend, it does not come in DIP8 package.
There are very pricey discrete opamps option like the Burson and Sparkos but very overkill. I don't deny they sound better than the fake stock opamps(probably any modern opamp does). But you might not hear any difference compared to cheap modern opams as previously mentioned.

i bought mine pre soldered on ebay, I wont link here but he sells a few of opamps that are only offered on SOIC on DIP8 adapters, for me my soldering iron tip is not very good at small legs so I would have spent more on equipment than the ebay seller charges for it pre-made. I also saw the LME49720 but at the time I can admit I was spec chasing on data sheets so skipped over it entirely.

 

[Deleted member 48726]

Nonsense. They have stolen nothing. Where on earth you get ideas like this? They have sourced a minor component which may or may not be counterfeit. Even if it is so, you have no idea if they did this intentionally or not.

If it bothers you that the one part that I tested and produces great performance may not be original, then purchase the unit and buy the genuine IC and put it in there. It doesn't bother me none for the reason I mentioned (that they are sourcing a very expensive amplifier IC from TI relative to the cost of this opamp).

Nonsense. This kind of QC and sourcing is alarming. And of course they would know if they carried out some kind og ISO on their production which makes source QC mandatory.

Stop condoning this, please.

 

[Deleted member 48726]

Perhaps the cause is the different voltage in the mains in Europe and in Japan.

Or lack of quality control?

 

[Fosi Audio]

Ok. I just received mine today. First thing I noticed is how well built it looks. It looks nothing like the Aiyimas.
Immediately I connected it to power supply, speaker cables and RCA cables....it sounds good. A lot of details and a very low noise floor. I loved it.
Then I proceeded to open it. No special tool except screwdriver and needle nose pliers.
I don't want to rain on anybody's parade but the Opamps are the old known fake NE5532. I removed them with some effort.
I'm attaching pictures of my collection of NE5532.
You can see the legit TI NE5532P and NE5532AP (low noise) opamps have a different color on the legs compared to the fake ones. The notch compared to the circle. The logo and label are painted on the fake one. The originals are engraved.
I just installed some OPA1656 on adapters I had available and that's it.
The Amp sounded very good before. Now it sounds better to me.
Don't ask for measurements. It don't have how.

Thank you all for your enthusiastic attention and your dedication, which has touched us. Due to the traditional Chinese festival of Dragon Boat Festival in the past few days, we were unable to interact with everyone on the forum regarding this issue in a timely manner. We ask for your understanding.

As a company, we deeply understand the importance of integrity, so we would like to explain the issue regarding the op-amp. Our NE5532 op-amps were directly purchased from TI's official website. We have retrieved the purchase order records and attached a screenshot of the order. Please be aware that certain confidential information has been blurred for security reasons. We hope this serves as proof that we are using genuine components.

We are also curious about why the NE5532 op-amps we use may appear different from what you have in hand. Therefore, we have sent an email to contact TI to seek an official explanation. Once we receive a response from them, we will promptly share relevant screenshots to inform everyone.

We encourage everyone to continue monitoring our products and work. If you notice anything suspicious, please feel free to raise it to us. We will make every effort to communicate with you and address any concerns you may have.

 

[Fosi Audio]

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.

Hi friend, sorry for not making the description clear enough. Actually, the orange knob is an optional accessory so you need to buy it separately. However, it's true that we gave it away as a gift to every backer who supported our project on Kickstarter.

 

[Fosi Audio]

Looking at this photo, you can see that the output inductor has been downgraded from PR photos such as HP.
I've found 3 different output inductor implementations so far while looking at some pictures of V3 pc boards. I was a little disappointed with this.

I don't agree with the way it's advertised, but I'm very happy with the sound that comes out of the V3.

Hi Toku, would you please help us point out the differences you found with some pictures? We'll look into it and check what was wrong. Thanks in advance.