Fosi Audio V3 Mono Amplifier Review

[SMen]

There are differences in OPAmps, but firstly they are marginal and secondly they are not to be found in the area of sound. There are very subtle differences in the area of reproduction of details, bass precision etc., but they are really small, because each OPAmp does its job.
The often heard differences in sound are very often due to a mismatch between the circuit and the OPAmp, which is why OPAmp rolling without background knowledge, experience and adaptation of the circuit is nonsense in most cases.

So yes they are small. The Fosi has a list of circuit compatible op amps and people can try for themselves with the two Muses 02's they receive vs the stock TI op amp, perhaps A/B 'ing with a well recorded mono recording. It's only a suggestion given the strange circumstance of only receiving 2! !!! I'm a glass half full kind of chap!
Maybe over on the user's thread it will be fun for those who wish (but only those who wish).

 

[amix]

VinylSonic

This one?

 

[amix]

I am in category of those who have tried, fried the brain to limit to find any difference.
But I am still hopeful….. may be one day

It might to have to do with age. I'm not stating that you are old ;-) , just recapitulating my last hearing test: I need to EQ above 4k and can't hear above 10k. The older one gets...

 

[iLoveCats]

This one?

Yes. Was a great idea. Last update was April 2023 on Kickstarter

 

[Eron]

Has anyone done a 2x Mono Aiyima A07 vs v3 Mono comparison at this point?

 

[drizzy]

Not sure if this helps anyone but late pledge supporters might only have their shipping address collected on the 25th of June. Only "bought" it yesterday but I'm already so impatient
They also confirmed that it would be shipped straight from China but there wouldn't be any extra duties or taxes, at least to the UK

 

[Roland68]

Has anyone done a 2x Mono Aiyima A07 vs v3 Mono comparison at this point?

Do you mean the monomode of the Aiyima A07 MAX?
I don't know of any mono version or monomode for the normal Aiyima A07.

 

[Sputnik]

I am hoping (from the continent of Europe) that it is going first to a warehouse (in the EU), and then on, with no tax demands on delivery. Someone on another post for another Fosi Kickstarter said that their V3 (I think it was) arrived quite swiftly, and without tax - I'm assuming it was pre-paid as happens on AliExpress for example, from wherever it is sent.

We shall see because, we will get tracking on dispatch I understand.

I asked Fosi and they assured me there would be no extra tax due for EU.

 

[Eron]

Do you mean the monomode of the Aiyima A07 MAX?
I don't know of any mono version or monomode for the normal Aiyima A07.

Yes sorry.. The A07 MAX in mono mode (2) vs 2 v3 Monos.

 

[Down South]

I asked Fosi and they assured me there would be no extra tax due for EU.

This makes a big difference. If the sender (from outside the EU) doesn't complete IOSS procedure you will get hammered. Imused to buy LPs from DIG in the UK but because they couldn't be bothered gotaxed and had to pay a Customs charges as well - no more business for DIG.

 

[Jon L]

Yes sorry.. The A07 MAX in mono mode (2) vs 2 v3 Monos.

To compete/compare with Fosi V3 Monos, Aiyma will have to come up with similar balanced monoblock design, which I'm sure is in the pipeline..

 

[Roland68]

This makes a big difference. If the sender (from outside the EU) doesn't complete IOSS procedure you will get hammered. Imused to buy LPs from DIG in the UK but because they couldn't be bothered gotaxed and had to pay a Customs charges as well - no more business for DIG.

Many Kickstarter projects ship their products from several continents. Shipping could be from the EU.

 

[LSPhil]

Could someone explain to me why you are buying mono amplifiers with the TPA3255 chip?

If you only have 4 Ohm speakers, there is no difference in output power between mono and stereo modes.

 

[Roland68]

Could someone explain to me why you are buying mono amplifiers with the TPA3255 chip?

If you only have 4 Ohm speakers, there is no difference in output power between mono and stereo modes.

Maybe your information is incorrect.
Almost all of Amirm's tests come to about 139 watts per channel for TPA3255 stereo amplifiers and over 191 watts for mono amplifiers, at 4 ohms.

 

[Megaken]

Or you could see this as an opportunity and embark on the journey to DSP and room correction

I did that (went to a minidsp with Dirac from marantz with audyssey) and are now going back because in my case the AVR room correction was far superior than the minidsp.

The minidsp without room correction sounds phenomenal though, but my room is garbage.

 

[LSPhil]

Maybe your information is incorrect.
Almost all of Amirm's tests come to about 139 watts per channel for TPA3255 stereo amplifiers and over 191 watts for mono amplifiers, at 4 ohms.

The difference between 139W and 191W is +1.39dB

I looked at Texas and it is a full 10% more power, which corresponds to about +0.5dB.

The real reason is the possibility of connecting a 2 ohm box, because then the differences are very big.

 

[DavidM1]

Could someone explain to me why you are buying mono amplifiers with the TPA3255 chip?

If you only have 4 Ohm speakers, there is no difference in output power between mono and stereo modes.

Easy. Sinad greater than 100, significantly more power than a PA5+, including down to 2 ohms, at much lower cost, balanced and SE inputs, lack of load dependency, auto standby and restart, manufacturer who engages actively with customers, no volume knob, not unattractive design.

If there was a stereo amp with these features, especially one without the need for power bricks, it too would be getting attention.

 

[3eaudio]

Easy. Sinad greater than 100, significantly more power than a PA5+, including down to 2 ohms, at much lower cost, balanced and SE inputs, lack of load dependency, auto standby and restart, manufacturer who engages actively with customers, no volume knob, not unattractive design.

If there was a stereo amp with these features, especially one without the need for power bricks, it too would be getting attention.

stereo version is coming

3e Audio TPA3251 TPA3255 Finished Amplifier with PFFB is coming!

Hi Amigos: It has been for around 2 years after we release TPA3251 and TPA3255 series amplifier DIY kits with post filter feedback design that improve the overall performance of the single chip itself. With many buyers(diyer) enjoyed our diy kits and having so many fun from their own diy...

www.audiosciencereview.com

 

[LSPhil]

Easy. Sinad greater than 100, significantly more power than a PA5+, including down to 2 ohms, at much lower cost, balanced and SE inputs, lack of load dependency, auto standby and restart, manufacturer who engages actively with customers, no volume knob, not unattractive design.

If there was a stereo amp with these features, especially one without the need for power bricks, it too would be getting attention.

Sorry, I wasn't clear. I compare two configurations, namely BTL and PBTL at 4 Ohm. The power gain is +0.41dB more for PBTL and the costs double.

I'm a fool and it's very good that you noticed that. I am now a big believer in buying Mono Amplifiers.

 

[DavidM1]

Sorry, I wasn't clear. I compare two configurations, namely BTL and PBTL at 4 Ohm. The power gain is +0.41dB more for PBTL and the costs double.

I'm a fool and it's very good that you noticed that. I am now a big believer in buying Mono Amplifiers.

I didn’t notice anything of the kind. You asked for someone to explain, which I did. The mono aspect wasn’t a concern to me but the things I listed influenced my decision. You’ve probably noticed I’m playing this with a straight bat.