This is a review and detailed measurements of the Fosi Audio V3 Mono class D amplifier. It was sent to me by the company. The price with the power supply I tested is US $139.99.
I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime audiophile would have! But monblock it is even though it is a very small block. Controls are on/off/trigger audio and selection of XLR vs RCA inputs -- just like the big boys!
I am not showing the sides of the amp but there are very large holes with attractive orange color grid showing through. Nice. Back panel is again a bit of a shock to the system seeing XLR input:
The power supply as noted, is quite beefy with 48 volts at 5 amps on tap (240 watts). The amplifier is stated to have PFFB implementation which for a class D amplifier means it should have no load dependency together with lower distortion. Let's see if we get these with our measurements.
Fosi Audio V3 Mono Amplifier Measurements
Let's start with XLR input:
Wow, I did not expect this class of amplifier to break through the 100 dB SINAD barrier but the V3 Mono does exactly that, placing it in our prestigious category of "excellent:
RCA input costs you some performance but I was relieved to not see any mains interference:
Distortion is still at provably inaudible -115 dB. I like that the gain is nominal 25 which is my new recommendation for amplifiers.
Noise performance is excellent and at full power, darn near approaches sate of the art:
Now the all important frequency response and load dependency test:
There is essentially no impact up to 20 kHz between the 4 and 8 ohm indicating very low output impedance, albeit with a bit of peaking. Compare that to non-PFFB amps such as Fosi Audio V3 stereo Amp:
Above we have 2 dB differential at 20 kHz.
Distortion is very low and only increases with frequency:
Let's see how much power we can get out of this little box:
Efficiency must be quite high as we get essentially the power we put in (the power supply likely has some headroom).
There is decent amount of power even with 8 ohm and with very low noise:
As note though, distortion does rise at higher frequencies:
Fortunately it is good where our hearing is very sensitive (below 5 kHz).
I also threw my suite of my punishing reactive loads at it:
Translating into watts:
Amazing that this little amplifier can handle even 2 ohm load! Note that these are short term power ratings.
There may be a bit of power on noise:
Conclusions
All I can say is wow! It is incredible how far these small amplifiers have come. It is the result of a manufacturer listening to our needs, implementing features such as balanced and trigger inputs, and proper feedback mechanism to essentially eliminate load dependency. I can't imagine asking for more from Fosi when it comes to such an amplifier. Everything is as good as you could possibly want.
It is my pleasure to recommend Fosi Audio V3 Mono amplifier.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime audiophile would have! But monblock it is even though it is a very small block. Controls are on/off/trigger audio and selection of XLR vs RCA inputs -- just like the big boys!
I am not showing the sides of the amp but there are very large holes with attractive orange color grid showing through. Nice. Back panel is again a bit of a shock to the system seeing XLR input:The power supply as noted, is quite beefy with 48 volts at 5 amps on tap (240 watts). The amplifier is stated to have PFFB implementation which for a class D amplifier means it should have no load dependency together with lower distortion. Let's see if we get these with our measurements.
Fosi Audio V3 Mono Amplifier Measurements
Let's start with XLR input:
Wow, I did not expect this class of amplifier to break through the 100 dB SINAD barrier but the V3 Mono does exactly that, placing it in our prestigious category of "excellent:
RCA input costs you some performance but I was relieved to not see any mains interference:
Distortion is still at provably inaudible -115 dB. I like that the gain is nominal 25 which is my new recommendation for amplifiers.
Noise performance is excellent and at full power, darn near approaches sate of the art:
Now the all important frequency response and load dependency test:
There is essentially no impact up to 20 kHz between the 4 and 8 ohm indicating very low output impedance, albeit with a bit of peaking. Compare that to non-PFFB amps such as Fosi Audio V3 stereo Amp:
Above we have 2 dB differential at 20 kHz.
Distortion is very low and only increases with frequency:
Let's see how much power we can get out of this little box:
Efficiency must be quite high as we get essentially the power we put in (the power supply likely has some headroom).
There is decent amount of power even with 8 ohm and with very low noise:
As note though, distortion does rise at higher frequencies:
Fortunately it is good where our hearing is very sensitive (below 5 kHz).
I also threw my suite of my punishing reactive loads at it:
Translating into watts:
Amazing that this little amplifier can handle even 2 ohm load! Note that these are short term power ratings.
There may be a bit of power on noise:
Conclusions
All I can say is wow! It is incredible how far these small amplifiers have come. It is the result of a manufacturer listening to our needs, implementing features such as balanced and trigger inputs, and proper feedback mechanism to essentially eliminate load dependency. I can't imagine asking for more from Fosi when it comes to such an amplifier. Everything is as good as you could possibly want.
It is my pleasure to recommend Fosi Audio V3 Mono amplifier.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
