Fosi V3 review
Hello audio lovers
I wanted to share with you one of those little diamonds that sometimes break into the market.
Fosi V3 a little gem that doesn't need much light to shine.
What is it about?
From a minimalist amplifier from the company Fosi, a brand that for a few years has been positioning itself as a reference in a market range that previously did not exist.
HI-FI has historically been inaccessible to the general public .
Fosi is offering products with a high level of quality at a very competitive price that allow you to enjoy quality sound at a reasonable cost
A great advantage of globalization and new communication channels is that the customer/brand relationship has changed radically.
In this case, the FOSI brand listens to its customers and takes their opinions into account in the product development phase.
Something unthinkable a few years ago and that changes the rules of the game, the client no longer buys what a brand has designed according to their ideas, the client is part of the project.
What does the FOSI V3 offer us?
In a very compact enclosure of 105x143x40 mm. hides a successful selection of components that in the sound test show their potential.
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The minimalist design offers a front with an operating indicator LED and a volume adjustment dial with a very good touch plus a silent connection "there is no expected connection / pop noise".
There is no remote control and I think it is not necessary, if you use it as a desktop amplifier it is within your reach and if it is a distant installation, remember your old school times without this accessory.
The rear remains minimalist, RCA signal input connectors, speaker output with screw/banana connectors and a 3.5 mm output with fixed signal level independent of the front regulator.
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Fosi in future reviews of the device indicates that it will be variable depending on the front regulator.
For this test I have two V 3 units, a 32V version and another 48V.
It is the same device where only the PSU varies, the PSU 48V is larger than the V3.
I have done the listening tests with HECO VICTA PRIME 302 speakers and a DAC S.M.S.L DO300.
Two configurations
- One V3 unit in normal connection mode
- Bi-wired mode with two V3 units (32V-48V)
Sound checks
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Preparation and deployment of equipment for testing
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Comparison between PSU
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Bi-amplification mode tests
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Wait a minute, where's the secret chamber? How is it possible to obtain this power with these micro dimensions?
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These are the maximum powers declared, in the range of 20 to 20000 hz and with Thd < 1% are lower but enough to move any box on the market with quality.
The test speakers offer a sensitivity of 90 dB (2.8V/1M) and during tests with the 32 v and 48 v versions give a good result.
The potentiometer offers a logarithmic curve in its operation, that allows a better more precise adjustment when you use a lower volume, it may seem strange but it is a resource used in professional audio regularly.
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The hated but necessary connection cables
So 32 V or 48 V? It all depends on the set and the power of use that you are going to use regularly.
You want quality sound at low volume, the 32V version is enough.
Is your installation demanding? Uses 48v
Music is clear and no background noise is present.
You can position the instruments in front of you and the timbre is totally neutral.
This sound will always depend on the speakers you use in your installation the V3 is only a neutral link in the sound chain , it does not color the signal.
In this sense, the V3, Fosi offers the possibility of replacing the NE5532 operational amplifiers as standard.
The V3 supports a variety of dual 8-pin op-amps such as Sparkos SS3602, MUSES02, OPA2604, OPA2134PA, OP249, AD827, RM4559, LM4562, LME49720HA
Among the different musical styles, from classical, pop, rock to techno, the V3 shows no fatigue or distortion.
The TPA3255 chip does an exceptional job, during the tests carried out and using techno music with a lot of bass the external temperature of the V3 did not exceed 40ºC with a starting temperature of 30ºC (Spain, August 2023, full heat wave).
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Bi-amplification tests
In the bi-amplification tests I used the 32V version to power the treble and the 48V version for bass.
Changes?
An improvement in sound clarity is achieved , an improvement in details since there is greater dynamics to work with the speaker.
In future tests I will perform a signal filtering prior to V3 to assign a frequency range to each V3.
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The usual version in the markets is the 32 V version (32V / 5A external power supply), although there is the version with 48 V / 5A source and the V3 only version without power supply, different options for different equipment, that added to the possibility of customizing the device positions it as a very useful component in the usual puzzles that are high-level sound equipment.
Conclusions
An essential component in main, secondary and desktop systems.
Pros
Build quality
Quality/price ratio
Power module performance
Possibility to customize operational amplifiers
Cons
Remote control? May be necessary in some cases
Pre-out output without regulation. We are in the same case as the remote control, a large majority of users do not use that function.
Specifications
Max Power Output: 300Wx2 @4Ω
SINAD: ≥88dB
SNR: ≥110dB
Terminating Impedance: 2-8Ω
THD: <0.003%
Power Amp: TI TPA3255
Op-Amp: TI NE5532 x2
Power Supply: 32V/5A, 48V/5A
Power Input Range: DC 24V-48V
Frequency Response Range:
20Hz-20kHz(±0.1dB)
