Fosi Audio V3 – Revenge Of The Class D Amp

Manufacturer: Fosi Audio Fosi Audio V3 – Revenge Of The Class D Amp

Fosi Audio reviews have become a tradition at PCPer, with their original Fosi Audio TB10D proving a very pleasant surprise instead of a product in search of a real world application and then the Fosi Audio BT20A Pro which improved upon the first in every way.   They recently release a newly designed amp, the Fosi Audio V3, which underwent a redesign specifically targeted at audiophiles that want both quality and value.  The capacitors were replaced with higher end Japanese ELNA, German WIMA and Japanese NCC filter caps, and the inductors are now Sumida.  They also changed the case, which now has venting and a heatsink attached directly to it to improve the thermals when you feel the need to crank it to 11 for just one more song.

The other, more obvious difference is the removal of the treble and bass controls, instead opting for proper balance on the inside and volume on the outside.  As they learned with the BT20A Pro, knobs matter and that is why the volume has a proper off setting as well as being a logarithmic Taper A pot instead of a linear pot.  They also included a second copper knob, if you prefer the look they started with the BT20 Pro.  Honestly, it’s hard not to look forward to a new release from Fosi as they have yet to disappoint.

Product Specifications
  • Max Power Output: 300Wx2 @4Ω
    • Power supply: 32V @ 5A
    • 24V-48V supported
  • Model Name: V3
  • Amplifier Chip: Texas Instruments TPA3255 x1
  • Op-Amps(Replaceable): TI NE5532
  • Control Knob: Power/volume knob, built-in logarithmic Taper A pot
  • Input: RCA line-in
  • Output: Speaker output, 3.5mm pre-out
  • SINAD: 88dB
  • SNR: >110dB
  • THD: <0.003%
  • Noise Floor: 140uV
  • Aluminium alloy enclosure with cooling vents on top and bottom. The Amp chip’s heatsink is attached to the enclosure making the whole case a heatsink
  • Japanese Sumida advanced high-power inductors
  • Japanese NCC filter capacitors, 2200uF/63V
  • German WIMA and Elna capacitors
  • Soft-start thermistor on the power input. Specialized circuit design ensures zero energy consumption after power-off to enhance longevity

$89.99 USD, but for you a $12 off promo code: FAV3MKT12

$119.99 CDN, $15.60 off with FAV3MKT12

Manufacturer Description

“Fosi Audio V3 is a mini HiFi class-D power amplifier tailored for audiophiles by Fosi Audio based on the voice of users. This is a pure amplifier designed only for high-fidelity sound enjoyment.

It integrates Texas Instruments’ high-end TPA3255 Class-D power amplifier chip, which can handle a maximum power output of 600W into two channels. It has ultra-high power efficiency and enables true premium sound quality.

Despite its compact size, it has the capability to drive your passive speakers without issues. It’s a great budget HiFi gear to accompany your turntable, CD player, and speakers to form a perfect HiFi system.”

The Fosi Audio V3 Is Kicking Audio From A Kickstarter

Fosi tried some new things with the Fosi Audio V3, including ensuring there was a market for this version by trying a Kickstarter for the first time.  There may be some mixed feelings about choosing that method for a somewhat established company, but it was also an interesting way to give those clamouring for an audiophile version of their pocket amplifier a chance to put their money where their mouths are.  Considering they hit HK$152,250 on a HK$20,000 goal, it was obvious there was a market willing to buy the new version and so here we are.

As with the previous two models they based the amp around the Texas Instruments TPA3255 as it has served them and many others very well.  The Fosi Audio BT20A Pro introduced swappable Op-Amps and Fosi kept that in this iteration for those that want something different than the TI NE5532 chips that come installed.  Their manual doesn’t list the compatible Op-Amps for this model but they are likely the same as listed in the BT20A Pro review, and possibly the TI TLV9362 as well.  Do be careful if you do open either amp up, the jacks are hard wired and there is just enough slack in the wires to make those op-amps accessible.  Do not yank happy Fosi amps!

You Gotta Keep ’em Separated

The Fosi Audio V3 yet again proved a pleasant surprise, swapping out the BT20A Pro which has been running my eight speakers for quite a while now immediately produced tangible differences.  The separation of the channels on the V3 have increased by at least as much as it did from the original TB10D to the BT20A Pro and the dynamic range has opened up significantly, perhaps more so on the treble than the bass.  It really helps the clarity of vocals, unless you are listening to Type-O Negative perhaps. 

The lack of treble and bass knobs will disappoint the fidgety listener but there is absolutely nothing wrong with the natural balance the Fosi Audio V3 outputs.  It does emphasize one of the proper places for a Class-D amp, sitting between unpowered speakers and something like a Focusrite pre-amp that offers comprehensive control over levels, but no power.  Fosi have also significantly changed the Total Harmonic Distortion, at <0.003% you get a very clean sound, again making it very appropriate for a musician that is looking to build a reference system.  The volume works as advertised, a satisfying click accompanies the shut off and the logarithmic pot really does give you better control over the volume the amp produces.  Caution, neither PCPer nor Fosi are responsible for noise complaints accrued during the use of the Fosi Audio V3.

swap me all night long

Encore! Encore!

There is one possible sour note for the Fosi Audio V3 for certain usages, lacking a proper amped subwoofer to test the veracity of a Kickstarter commenter, it is reported that the pre-out on the V3 is actually a fixed-level line out.  That will not be a problem for many, and it will still allow you to make good use off an external power amplifier if that’s the way you roll.

Apart from that the Fosi Audio V3 is brilliant for anyone who is looking for a Class-D amp to drive reference speakers, or if feed it high quality audio and prefer a crisp sound to the warmth of the previous two amps.   The Bluetooth input of the BT20A Pro as well as the treble and bass knobs make it a better choice when you are diving into a night of music on YouTube, which you should keep in mind.  For a night of pure audio sensation or for mastering a track you laid yourself there is no question the Fosi Audio V3 is the way to go.

Fosi’s goal is to “make audiophile-grade sound accessible to everyone” and the V3 lives up to that in every possible way; wonder what their fourth kick at the cans will bring!

It's one louder

Review Disclosures

This is what we consider the responsible disclosure of our review policies and procedures.

How Product Was Obtained

The product is on loan from Fosi Audio for the purpose of this review.

What Happens To Product After Review

The product remains the property of Fosi Audio but is on extended loan for future testing and product comparisons.

Company Involvement

Fosi Audio had no control over the content of the review and was not consulted prior to publication.

PC Perspective Compensation

Neither PC Perspective nor any of its staff were paid or compensated in any way by Fosi Audio for this review.

Advertising Disclosure

Fosi Audio has not purchased advertising at PC Perspective during the past twelve months.

Affiliate Links

This article contains affiliate links to online retailers. PC Perspective may receive compensation for purchases through those links.

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About The Author

Jeremy Hellstrom

Call it,, or PC Perspective, Jeremy has been hanging out and then working with the gang here for years. Apart from the front page you might find him on the BOINC Forums or possibly the Fraggin' Frogs if he has the time.


  1. Operandi

    I’m pretty sure the pre-out is an actual “pre-out”, not a “line out” based on the other reviews I’ve seen / read. Speaking of the pre-out since they are going upscale with the V3 it would be nice if they would make that full sized RCA instead of the 3.5mm. I would also be nice to see another set of inputs so people could have say one input from a DAC and one for TT to cover their digital and analog basses.

  2. Chris

    I think wishing for more features on the V3 is basically saying I want another amplifier. If you want a good amplifier with all your favourite functions, they already exist by the dozen. They also cost a lot more. In my opinion, the V3 is perfect. It allowed Fosi Audio to produce a quality item at a rock bottom price. It breaks the the old law of diminishing returns that is so prevalent in the audiophile world.

  3. Dean Woody

    To my 70 year old ears, this is right there with how a 40 watt $450 Sony Receiver sounded in the 70’s.


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