Fosi Audio V3 monoblock Review

Introduction

Fosi Audio’s mission to turn your desktop into a haven of audiophile sound quality as well as a place of business continues unabated.

The company’s latest attempt to elevate your workstation is this – or, rather, these: the V3 monoblock Class D power amplifier(s). The price is right, the specification is right, the dimensions are right. Just the sound to go, then… 

Design

• 41 x 107 x 142mm (HWD, each)
• CNC-machined aluminium chassis
• Whole-body heatsink design with side ventilation

Compact doesn’t really begin to cover it. Each V3 monoblock is an extremely tidy 41 x 107 x 142mm (HWD) and similarly manageable 750g – so once a stereo pair is stacked one on top of the other, there’s no danger of their dominating even a smaller desk. The fact that the power brick each amplifier needs in order to do its thing is comfortably larger than the V3 itself should be neither here nor there, given that they’re likely to be on the floor and out of the way.

As with every Fosi Audio product I’ve encountered, the V3 monoblock is properly constructed and expertly finished. The chassis is made entirely of CMC-machined aluminium, which helps it look and feel rather more upmarket than the asking price suggests, and the design turns the amplifier into a whole-body heatsink. This arrangement, in conjunction with dust filter-covered ventilation circles along each side of the chassis, means the V3 runs reasonably cool – certainly there’s no issue with stacking them, as heat-soak is not an issue.

As is predictable when the strictly defined functionality of the V3 monoblock is taken into account, the fascia is not overburdened with controls. There are two little toggle switches, both very positive in their action – one is for power (on, off or auto) and the other is to select between the line-level inputs (RCA or XLR/TRS).

Specification

• Texas Instruments TPA3255 Class D amplification
• Claimed 240 watts into a 4-ohm load
• Texas Instruments NE5532 op-amps are user-swappable

On the rear of the V3 monoblock you’ll find three line-level analogue inputs. There’s an unbalanced RCA socket and a hybrid balanced XLR/6.3mm TRS alternative – the RCA socket is accompanied by a gain switch, with 25dB or 31dB settings available. Outputs consist of positive and negative speaker cable connections – banana plugs and bare wire connection are both supported.

Amplification comes via the well-regarded Texas Instruments TPA3255 Class D chip that I’ve recently heard powering the new WiiM Amp Pro. It’s accompanied by some equally credible hardware, including Sumida audio inductors, WIMA capacitors and Nichicon filter capacitors. The Texas Instruments NE5532 op-amps can be swapped by the end user in favour of alternatives from, say, the likes of Burson or Sparkos – which will please inveterate tweakers no end, I’d have thought.

A four-layer PCB is designed to offer optimal signal stability and purity. And in an effort to overcome the usual load-dependency issues inherent in Class D amps, Fosi Audio has developed something it’s calling PFFB (‘post-filter feedback’) – it intends to reduce output impedance and output filter impact on frequency response. In fact, the company is claiming a frequency response of 10Hz – 30kHz for the V3 monoblock. 

Performance

• Detailed and quite well-defined sound
• Energetic and punchy
• Lacking top-end substance

In broad terms, Fosi Audio has struck quite a nice balance with the V3 monoblocks. They may not be able to describe big dynamic variations with all that much conviction, and they could do with a bit more body at the top of the frequency range, but in every other respect they’re likeable and easy to listen to – as long as they form part of an appropriate and proportionate system, of course.

A 24-bit/44.1kHz FLAC file of Aw, Shoot! by CMAT via TIDAL enjoys nice detail levels at every point, and the midrange resolution is such that some of the details of her technique (as well as the location of her regional accent) are made apparent.

There’s a respectable amount of punch and variation at the bottom of the frequency range, as well as a fair amount of extension. Frequency response is helpfully even, and with the exception of the treble reproduction (which is flimsy and just fractionally hard) the tonal balance is pretty convincing too.

The soundstage the amplification generates is reasonably large and defined effectively – the spread is much more left-to-right than it is top-to-bottom, which allows every element of a recording a bit of breathing space. Control of low-frequency activity is quite accomplished, which means rhythms are expressed with a fair amount of confidence, and the same is true of tempos.

The V3 monoblocks’ overall attitude is quite energetic and upfront, and while this suits up-tempo material rather more readily than it does the down-tempo stuff, it means the Fosi Audio is never less than an engaged and engaging listen.

No, the amplification doesn’t really have the lung capacity to give full expression to the biggest shifts in volume or intensity. No, it’s not an especially three-dimensional listen – the soundstage is coherently laid out but there’s not much sensation of a front and back to the presentation. And no, the high-end response isn’t the most substantial you ever heard. But if you balance these negatives against the V3 monoblocks’ positives, they definitely emerge in credit.    

Should you buy it?