Fosi Audio V3 Mono Amplifier Review

[amirm]

I saw that it is possible to connect one 48v power supply to 2 monoblocks with a splitter cable. Will it reduce the power of both amps?

It would.

 

[Booker]

There is an optional 48V/10A Power Supply.

Fosi Audio V3 Mono Monoblock Power Amplifier

The V3 MONO is a monoblock high-power amplifier integrated with the Texas Instruments TPA3255 amplifier chip, suitable for speakers of 2Ω to 8Ω impedance. It implements Post-Filter Feedback (PFFB) technology, addressing the long-standing issue of load-dependency in Class-D amplifiers.

fosiaudio.com

Scroll down to the bottom of the page.

 

[gvl]

Just read this from the company in their message to me when the amp was sent:

"We'll provide a bundle including two V3 mono amps and a 48V/10A psu for no more than 260USD. That single 48V/10A psu can power the two sets of v3 mono simultaneously."

This would defeat the purpose of mono blocks which is being able to keep them close to speakers with shorter speaker wire.

 

[gvl]

You can never have too many amplifiers.

Well, that's not true. I have too many. Don't be like me. But I will say these little high performing things would be really easy to smuggle in to the house and hide wherever you wanted...

Think of it, you could have 10x times more if they were all this size Hoarder friendly form factor, hehe.

 

[Talisman]

The distance between source and speakers always remains the same, with or without monobloc, if you want to shorten the power cables you will have to lengthen the signal cables and vice versa, no free lunch. Between the two options I prefer to have longer speaker cables than signal cables.
As far as I'm concerned, the advantage of monoblocks is the elimination of crosstalk

 

[kibs]

Just realised why I need a DAC with XLR outputs. My SMSL SU-1 has an output voltage of 2, compared to the 2.8 I'd need to run this to max power.. Then I'd also take a sinad hit with RCA inputs..

 

[gvl]

I see the opamps are swapable. However, it doesn’t look like there is enough space for the boutique discrete opamps that audiophiles believe influence sound quality.

It's nothing that a drill and a file can't fix.

 

[gvl]

The distance between source and speakers always remains the same, with or without monobloc, if you want to shorten the power cables you will have to lengthen the signal cables and vice versa, no free lunch. Between the two options I prefer to have longer speaker cables than signal cables.
As far as I'm concerned, the advantage of monoblocks is the elimination of crosstalk

Long balanced signal cables are a non-issue. Long speaker cables can be. As for crosstalk, how do you plan to eliminate it between speakers in the room?

 

[Sokel]

It's nothing that a drill and a file can't fix.

 

[Talisman]

I don't think in any home audio context speaker cable length is a real issue using the right wire gauge

 

[restorer-john]

Just realised why I need a DAC with XLR outputs. My SMSL SU-1 has an output voltage of 2, compared to the 2.8 I'd need to run this to max power..

The amp has a gain switch on the back. @amirm will know the two settings- one is 25dB, the other 31dB probably. So you could happily use the S-1 if that's the case.

 

[Sokel]

The amp has a gain switch on the back. @amirm will know the two settings- one is 25dB, the other 31dB probably. So you could happily use the S-1 if that's the case.

Yep,hard to see but you're right on:

 

[Talisman]

 

[antcollinet]

This would defeat the purpose of mono blocks which is being able to keep them close to speakers with shorter speaker wire.

Not if the 48V wire is long enough - or extended to be.

In any case, I'd rather have longer speaker wire, with shorter low voltage interconnect.

 

[antcollinet]

I saw that it is possible to connect one 48v power supply to 2 monoblocks with a splitter cable. Will it reduce the power of both amps?

Not if the PSU with double the current capacity (10A) is used.

 

[gvl]

Not if the 48V wire is long enough - or extended to be.

In any case, I'd rather have longer speaker wire, with shorter low voltage interconnect.

I guess. I'd prefer 2 power bricks, as increased load in one channel can affect the other channel performance, not quite mono-block anymore.

 

[Yorkshire Mouth]

I know I'm gonna get a lot of hate for this. But here goes, these amps are great, no doubt and an excellent value. But what is the deal with external power supply? And what is the deal with that cute little miniature size form factor, is it meant to be a desktop amp?

Can't we just put two of these mono and their power supply into one case? Who started this silly trend? It screams dorm room HiFi component.

I’m personally of the opinion that hi-fi listening is moving to desktop set-ups. Not entirely, but I think there’s been a large and relatively rapid shift.

Just my opinion, but based on what I experience at these forums.

 

[restorer-john]

View attachment 360792

31dB is probably a bit hot for 2.0V, but 25dB is a bit low- it depends on the steps and range on the D/A's digital volume. I'd set it for 25dB and only change it to 31dB if I was constantly up near 0dB on the D/A's output vol.

I think this little unit could be a really good seller for Fosi.

 

[Saponetto]

An elegant step in the right direction.
Well done, @Fosi Audio, and as usual many thanks for the appreciated review, @amirm!

 

[Yorkshire Mouth]

How do 2 of these compare with stereo balanced amplifier, Topping PA5 II (about US$250 now)?

In other words, which is the better option, for which use case.

Thanks.

My question too, as I’ve pencilled in a system based on the PA5 II and upcoming WiiM Ultra.

You know the WiiM Amp was so highly rated, apart from the amp could have been a bit better? I think the Ultra and this look set to be the high end ‘problem solved’ version of the WiiM Amp.