Fosi Audio V3 Mono Review. Tons of Affordable Power! 

While I do agree that two separate power supplies are far better than this silly Y connector they're pushing, I do have to disagree on the voltage part. These TPA3255 chips producing all this output are, in real life, about the size of your pinky's fingernail and only 1.2mm tall. That is an awfully small mass for so much power and they run surprisingly hot, even with huge heatsinks and forced air ventilation. (Picture a large CPU cooler) In a small mini-amp like these the case will be warm (perhaps very warm) but without that over-the-top cooling solution, the chip itself is going to be roasting hot before the case heats up. If you push it with the 48 volt supply, the chip will heat up, go into a thermal panic and shut itself down; which is not a good thing. This will only get worse if you are wedging them in among other things or stacking them. Then, worse again when the case gets dirty and no longer radiates the heat away as efficiently. In my experience it is clearly unwise to try to suck as much power out of these tiny casings (with no real heat sink) as you can. You will shorten the chip's life significantly. But there is a sweet spot of sorts that you can capitalize on very economically. At about 35 to 40 volts these mini-amps will run warm, but not dangerously so, and they will still give you enough power to safely run a pair of large towers in a medium sized room up to ear-bleed levels. Since 40 volt supplies are not commonly available I've been recommending 36 volts at 5 or 6 amps, which are readily available from most online vendors. At this level you will get abut 75 watts on 8 ohms or 140 watts on 4 ohms with very low distortion. The amplifier itself will then last several years instead of several months, and should be totally maintenance free. (except for keeping the case clean.) For your scenario... long signal lines, short speaker cables... the amplifiers would be powered by separate 36 volt supplies, all tucked away behind your speakers and plugged into the nearest outlet. The audio would be coming through Balanced XLR or TRS cables from your pre-amp. Should be a really nice setup!

Yes I have a copy of Amber Rubarth’s Sessions from the 17th Ward

I think I will have a giveaway for it, happy with mono’s

they also offer a 48v 10a power supply for more current of which I'm ordering two, one for each amp; I currently have two ZA3 in mono mode with dual 5a and they feed my power hungry Magnepan 1.7i with no problem and sound great...

@@michaelcampbell9459 what's the current capabilities of the output stage? No sense upgrading the PSU if you're still limited by the output stage.

@@dicmccoy According to the "TPA3255 Spec Sheet" (do a search) In the PBTL mode used in these amplifiers the TPA3255 can source up to 17 amps of current. In measurements, I've seen them produce 28 volts RMS across a 4 ohm load... Which works out to 196 RMS watts... or 277 Peak watts at well under 0.5% distortion. That requires a "mere" 7 RMS amps (10 Peak) of current. In anything but the most stupid of situations, these wee beasties will end up averaging about 4 or 5 watts on music -- which is really freaking loud, btw -- with all that extra horsepower available for those big tympany hits or movie explosions. It's unlikely you're going to even get close to their limits in normal use.

@michaelcampbell9459 There is no benefit in doing this. The 10A supplies are designed to run two amps from one power supply and there is no audible benefit having two of these over having two separate 5A power supplies. I asked Fosi this question as I considered doing this myself.

Yes. If you want to know what these things can really do, hook them up to a pair of decent workhorse speakers ... Heresys or L-100s ... you're in for a real treat. The only thing I would caution you is that, unlike tube amps, Class D amplifiers do not clip gently and they don't like it. They will get very hot and go into protection. So if your music carries a lot of distortion, you will need to get it from the input side, not by overdriving the outputs.

@@Douglas_Blake_579 thanks Doug

Haven’t heard the WiiM amp

@@TheBoomerConsumer Same amplifier chip ... do the math.

@@Douglas_Blake_579 I don't know how the V3 mono sounds but i have had the Wiim Amp for a very short time and for me the SQ was really disappointing in my situation/setup (swapping it with a NAD C700). I also compared the Wiim Amp with the the Fosi Audio ZA3 (which also has the same amplifier chip i believe) in combination with a Wiim Mini. That already sounded better then the Wiim Amp. Things really improved when i also added a SMSL SU-1 dac. Now it comes closer to my NAD C700 but the NAD still sounds a bit smoother/tad warmer also.