Fosi Audio V3 Amp Review (1) – Palm Sized Punch?
In this Article
HERE WE ARE
There is something enticing and comforting about big chunks of aluminum, copper and steel that emit heat while pushing electrically charged particles around and with these small black box amplifiers, Fosi Audio V3 shifts the goal posts and somehow invites curiosity from the opposite of excess.
Cramming it full of all the audiophile buzz word components and features at an affordable starting price of $89, or unlocking more power at $109, what us power hogs identify as an amp might be slowly shifting.
Fosi Audio appears to be active listening and have taken part in the forum communities to pluck what drives reliability and credibility to an audio product. What we get in return is a well thought out desktop amplifier for those chained to a desk, or that could also serve as the anchor in a nice 2 channel setup as long as power expectations are kept in check with the included power supply.
LET’S TALK DESIGN CHOICES
With these small black box amplifiers, Fosi Audio V3 shifts the goal posts and crams it full of all the audiophile buzz word components and features at an affordable starting price of $89, or unlocking more power at $109. They appear to be active listening and have taken part in the forum communities to pluck what drives reliability and credibility to an audio product.
What we get in return is a well thought out desktop amplifier for those chained to a desk, or that could also serve as the anchor in a nice 2 channel setup as long as power expectations are kept in check with the included power supply.
Apart from the very obvious marketing blurbs about Japanese Elna and German Wima capacitors, along with Japanese Sumida inductors, we get a UL certified power supply included with the Fosi Audio V3 when selecting the 32V option. Seems like a small win, but that means it passes all safety requirements.
That is not to say the original power supply provided with the TB10D or the BT30D Pro were dangerous, it just means they are willing to go the extra mile. There are actually two options when purchasing the Fosi Audio V3 direct from their store, the one supplied with a 32V power supply ($89) or the one with a 48V supply ($109). The power supply by itself sells for $59, so a much better value choosing the 48V. This is also another win.
However, I wish they would cut it out with the 300W irrelevant text pulled from the Texas instruments data sheet. Hopefully they are not fooling anyone, but I am sure there are true believers. To reach those levels, it requires a 51-53V supply and those power ratings are with 10% distortion, and most likely poor SINAD numbers.
Coming back to the parts used, they designed it using reputable parts and swap-able op-amps that pays homage to the days of tube swappers. It does come supplied with the workhorse NE5532 which is a solid choice and rather inexpensive these days (~$0.67 non-bulk pricing).
Of course those with tweaking hands will definitely open it up and probably swap in MUSE op-amps or some Burr Brown. What I would like to see from brands that offer this flexibility is actual verification that certain op-amps are compatible. With the wrong circuit design, a “better” op-amp can actually invite instability and oscillations.
Fosi Audio does appear to consider recommendations and also made sure to capitalize on that by actually offering the MUSE02, OPA2134PA, and OPA2604PA. I have dabbled in op-amp swaps with one of my Audiotrak Prodigy soundcards using the OPA2227, OPA2134 and am familiar with Douglas Self testing from over a decade ago, but the NE5532 is a fine op-amp to stick with.
Other features or rather non-features of the Fosi Audio V3 include only a tapered logarithmic on/off volume knob and the subtraction of any tone controls that might detract from a purist experience. Logarithmic volume controls give the user better control to find the volume sweat spot without large jumps in the output power.
There is also a 3.5mm pre-out connection however not sure what purpose it serves other than to daisy chain a headphone amp to it. The pre-out works whether the amp is on or not so therefore it is not tied to the volume control. If it were, then we would have a proper preamp for a subwoofer.
The Fosi Audio V3 does exhibit a small blip (not a pop) when turning on. It would not even remotely damage anything I am only pointing it out because Fosi claims noise free turn off-but they are clever by not mentioning turn ON noise.
Cooling did not seem to be a problem on the TB10D, but the Fosi Audio V3 adds ventilation holes on the top and bottom. The size of the case is the same as the TB10D and about the size of a computer mechanical hard drive. If anything it would aid in any heat buildup in the filter inductors. Regardless, it stays cool to the touch even during spirited listening sessions.
HOW DOES THE FOSI AUDIO V3 SOUND?
Several of my friends gave the Fosi Audio V3 a listen paired with an Adcom GCD-600 CD player and vintage Kef 103.2 speakers (8 ohm)- a far stretch for bookshelf speakers. I also paired it with a SMSL C200 DAC and Behringer Truth B2030 (4 ohm) nearfield monitors.
Volume was plentiful, bass was tight and controlled but not given a chance to blossom as it did with an Nelson Pass designed Adcom GFA-545. Probably not fair given the highly regulated power supply of the Fosi compared to the linear power supply of the Adcom with its ample capacitor power reserve and more power for dynamics.
Also keep in mind the Adcom can easily supply 100W at 8 ohms and the V3 is closer to 30-50W. An unfair advantage for sure until you remember one can take up minimal space on a desktop, and the other is geared for equipment rack usage.
The Fosi Audio V3 had quick transients almost to the point of sounding too clean, we all seemed to prefer the more organic nature of the Adcom although I admit we did have sighted bias going on. Also due to depth reproduction, layering was crunched giving a flatter stage presence.
I think our biggest take away was there was something going on in the treble mostly noticeable on cymbal hit-hats making them sound over-damped and trimmed. The Adcom let them ride a bit. Like biting into an apple that has been stored too long, the essence is there but the flavor and juice are missing. Surprisingly, I felt the Fosi Audio TB10D fell somewhere between the GFA-545 and the Fosi Audio V3 in cymbal reproduction, but delivered a boxed in stereo image.
I did notice the Fosi Audio V3 does not have the same power output as the TB10D despite the same power supply and amp chip. This was noticeable by turning both volume knobs as high as possible and using the DAC as the volume. Based on some sleuthing over at AudioScienceReview (ASR), it appears they might have opted to improve some measurement figures in lew of power output. This is how you can play numbers gains with amps.
TB10D = 29db gain at 76 SINAD
V3 = 26dB gain at 88 SINAD
In a desktop near field situation, staging is excellent and there is plenty of depth and width at play. The Adcom sounds more spacious, wider, and deeper as a result of the more expressive low end, while the Fosi Audio V3 sounded more even with less front to back definition and more focus. Timbre is a touch towards uncanny valley syndrome, sounding less wholesome otherwise sounds clean and transparent. Compared to their TB10D, the V3 improves upon stage width and stereo image.
FINAL POINTS
The Fosi Audio V3 is a great desktop amp, but is not going to replace a full fledged well designed two channel amp. As with all class D designs using a passive filter on the output we end up with load dependent frequency response on the Fosi Audio V3. Fosi made the right decision to reduce output power and go for a cleaner transparent amp with no tone controls.
In a desktop near-field situation the extra power is not needed, and extra cleanliness is applauded, however the treble sounds thinned out and has room for improvement in resolution. The V3 improves on stage width and does sound cleaner over the TB10D. I would have preferred a pre-out controlled via the volume control.
I hope to revisit with the larger power supply, to see if that helps unleash more potential, but as it stands there is plenty of juice for a near field application to reach reference decibel levels with ample dynamic headroom in an affordable package. Keep an eye out for sales, they tend to run promotional discount codes. The Fosi Audio V3 is a great recommendation around the $100 price point for a straight-forward no nonsense desktop amp.
Disclaimer: I am grateful that Fosi Audio provided the V3 despite my poor response time. Had I been more aware of my surroundings, I would have requested the 48V power supply. If I can get the 48V supply, I will update my review or have a secondary review if I can also locate my op-amp stash.
Get it from Fosi Audio, Amazon or Aliexpress
Fosi Audio Store (where you can select 48V power supply option currently): https://fosiaudioshop.com/products/fosi-audio-v3-300w-x2-2-0-channel-hi-fi-stereo-audio-amplifier-with-tpa3255-chip
Amazon: https://www.amazon.com/Fosi-Audio-V3-Amplifier-Component/dp/B0C36S8DCT
Aliexpress: https://www.aliexpress.us/item/3256805418717043.html
SPECIFICATIONS
Chip Set TI TPA3255
Output Power 300Wx2 @4Ω
Terminating Impedance 2-8Ω
Input Mode RCA
Output Mode Speaker Output + Pre-out
Frequency Range 20Hz-20kHz(±0.1dB)
SINAD 88dB
THD 0.003%
SNR ≥110dB
Control Knob Built-in Logarithmic Taper A pot
Device Dimension 6.5×4.1×1.4 inches
DC Input Range 24-48V
Power Supply 32V/5A, 48V/5A
DISCLAIMER
Our generic standard disclaimer.
