Vinyl Review

The Fosi Audio V3 Mono is a high-performance monoblock Class-D power amplifier designed for audiophiles seeking high power and clean sound in a compact form factor. As a monoblock, it powers a single channel, meaning you typically need two units for a standard stereo setup. 

Key Features & Performance

• PFFB (Post-Filter Feedback) Technology: This is a major technical upgrade that overcomes common Class-D load-dependency issues, resulting in a more stable frequency response and significantly reduced distortion.
• High Power Output: It utilizes the Texas Instruments TPA3255 chip, delivering up to 240W @ 4Ω (with a 48V power supply).
• Connectivity & Gain: Features both balanced XLR/TRS and single-ended RCAinputs. It includes a gain selection switch (typically 25dB or 31dB) to match different preamps or DACs.
• Audiophile Components: Built with high-end parts, including Japanese Nichiconand ELNA capacitors, German WIMA capacitors, and Japanese Sumida inductors.
• Customisable Sound: Supports swappable op-amps (DIP8 dual discrete), allowing you to tailor the sound signature using chips like the Sparkos SS3602 or MUSES02.
• Auto Standby Mode: Automatically enters a power-saving standby mode after 10 minutes of no signal.

Overall: I love these monoblocks. They are the first I have owned but the XLR input, when compared to the phone input, yields zero noise. I mean ZERO.

They do run warm and I have modified mine so they have heatsinks on the top and slow moving fans blowing down onto them. This means they run very cool instead of very hot (their natural state). A lot of guides suggest fans underneath but I have found I can run these cooler on my configuration. This is mainly due to the chassis itself being designed to be part of the cooling system. When combined with heatsinks the chassis cools everything down perfectly.

I would not use these without any mods. The heat will kill them fast and some sort of active cooling is the only way to run them. Passive cooling will not cut it as the thermal degradation of components will prevent these from being a long term part of your system.

For the sake a £30 extra to cool them, these rock. One day I might even look into changing some of the chips out to see if I can get even more from this great, budget offering.