Fosi Audio V3 Amplifier Review

[peng]

The Fosi V3 is an integrated amplifier as well. It integrated preamp and power amp. To use it as a power amp only, you would disable the attenuation buy setting it to full volume. The same is true for the Yamaha receiver (which is a preamp, radio receiver and power amp in one) from above (or the Yamaha A-S201, which is preamp and power amp and phono preamp).

You are right, it has passive volume control, though in my opinion (just my opinion) it is not even a passive preamp because traditionally preamp implies more than just volume control. It is almost like one of those DACs (I have a few) that has volume control capability and they are still sold as DACs. Again, you are right by saying that it is also an integrated amp in a sense. The A-S201 seems to be a real integrated amp in traditional sense, that it might also has active (the 301 has active for sure, but not sure about the 201, it might be passive) volume control.

 

[gasolin75]

Beginner question. For the best amplifier performance from the Fosi V3 (least noise and distortion) and I plan on controlling volume with another device, should I leave the Fosi V3 gain at max? Or a little lower than max? Or whatever my prefered max listening level is when source is at max?

you should play the loudest recorded song you have and adjust the volume on the v3 to what you like when the volume is at max on the unit you use for volume, of course with no distortion

when playing any music you know the sound only distorts if the song are recorded with distortion and you know you can't damage the speakers since you adjusted the volumes so it never distorts with the volume at max on you main unit you use for adjusting the volume

 

[Kunti]

I will get 48v from fosi.
Hesitant to buy another product.
48v recommendation from fosi. Didn't know how hot it would get. Maybe I'll add a small fan on top with a USB tip. Daytime temperature 30-31c, and I will try it with ns-f51 to compare and choose.

My room is 13x10 feet.
I sit 8 feet in front of the speakers/tv. 1 foot from the wall behind the speaker, approximately 4 feet from the left and right speaker walls.
I run v3 every night, Music and movies. Optical to TV and Bluetooth. It replaces the htr2071, reducing the power slightly.

My impressions of v3.
looks nice, attractive and simple.
nice detailed sound. Previously I used TB10D. and I sold it, for better bass and tribal v3.
However, there is a difference in sound character when increasing the volume.
and sometimes makes the ears tired. Everyone's hearing is different and determines what is best for my ears.
tb10d is good.
Not bad when playing it hard. miss him a little. Bass and Treble buttons
are available.

 

[antcollinet]

That depends on where you are in the world. Also, the cheapest Yamaha has 4x the functionality. Plus a remote!

Which just shows you get what you pay for (at least at this end of the market)

I have it on good authority that @amirm recently bought a very, very cheap Yamaha device that is almost on par in terms of cost with a V3@48v.
I'm waiting for the test and hope it's measurements end up in the same region as the V3. The device in question has vastly more features. It's not the same ball park. It's not even the same sport.

I'll be interested to see that test also.

 

[antcollinet]

A remote controlled volume control and source selector at least.
At least!

On the other hand - the V3 is perfectly suited to my application. Desktop use connected to a PC as the only source. Volume dial within reach, and the 32V PSU fine for sitting <1m from the speakers.

The extra money spent on even the cheapest Yamaha would be wasted.

 

[Juampa1989]

The only thing I would have added is the remote control. I bought a separate dac just for this reason. I like that it's simple, no Bluetooth, no tone control, one knob (I never turn it off), and no channels. Simple is perfect, but since I use it with the TV I have to Get up to lower the volume.

 

[olieb]

The extra money spent on even the cheapest Yamaha would be wasted.

Exactly my point.

I just ordered two V3, together for 108 € (48V). I am planning on using them as power amps for a couple of active 2-ways. I would not care for any kind of additional functionality, quite the opposite. I'd even like to get rid of the volume control in favor of a switch to change the gain, ideally separately for the channels.
But I know it is very unlikely such a Fosi amp will see the light of day.

 

[wpo7]

Might make a pop sound leaving it on all the time when turning it off not using the volume knob ?

Would there be any white noise having the volume form a v3 at max all the time, like more white noise relative to the music ?

I leave on fully cranked and turn on/off with a wifi socket. control volume with phone android app. small tick barely audible on power on fwiw.

 

[TheBatsEar]

I just ordered two V3, together for 108 € (48V).

How? Where?
What?

 

[antcollinet]

View attachment 314428
How? Where?
What?

I looked at that askance too. I'm assuming he means "each"

 

[olieb]

How? Where?

On Ebay from Shenzhen. https://www.ebay.com/itm/354965042557 There was an extra discount for orders over 100€.
They have not been delivered yet ;-) but the seller looks ok. We will see.

 

[TurtlePaul]

Or whatever my prefered max listening level is when source is at max?

I would go with this. You can use still use the source volume control but you aren’t throwing away sound-to-noise ratio by maximally amplifying the source’s noise floor when its volume is set low. However, for most modern DACs it shouldn’t really matter.

 

[bitdo]

Might make a pop sound leaving it on all the time when turning it off not using the volume knob ?

Would there be any white noise having the volume form a v3 at max all the time, like more white noise relative to the music ?

I checked. Normally listening spot I didn't hear anything. Putting my ear one inch from the tweeter and I could hear some faint white noise. It was there regardless of gain. At max gain the white noise wasn't as even. It had a little extra crackle or fiz. But still faint and not audible from listening distance (2m).

Leaving it on all the time I haven't had pop issues when my sources turn on. After I get the triggered power strip i'm curious if the V3 will make any additional pops louder than the power relay turning on.

 

[tades]

What would be the best match for getting best power from
Fosi 48V 5A or Audiophonics 42V 8.5A power supplies?

Is this correct to expect max 48v*2.5A =120W per channel if Fosi
and 42*4.25A = 178.5W with Audiophonics whatever the load between 4 and 8 Ohms?

 

[gasolin75]

This one https://www.audiophonics.fr/en/hifi...-supply-100-240v-ac-to-48v-7a-dc-p-14749.html

48v*2.5A is more then 42*4.25A

I would say no

where do you get the 2.5 a and 4.25a from ?

I think if gain is 26 db, the a usage would be the same but because of the difference in voltage the 48 volt psu will make the amp play louder

The speakers are the same, the impedans is the same, the max gain from the amp is the same, i thing what amps (a) it uses is the same, the only thing that changes is is the voltage, since i don't think the amps would use more then 4-5a out of 5 and 8.5a (because the amps gain isnt high enough for the amp to need more then 4-5a).

 

[tades]

Hello Gasolin75
I thought that if the Power supply is 48V on let's say an load of 6 ohms, U/R = 48V /6 Ohms 8 Amps is requested per Loudspeaker
But Fosi is limited to 5A in total so 2.5A per channel
So per channel P=U*I =48*2.5= 120W per channel

Same with 42V , 7A requested ; but 8.5A in total, thus 4.25A per channel
So per channel 42*4.25 =178W

But effectively I didn't think about Max gain (I remember i have read 20x on Fosi V3 so yes 26dB
Can you elaborate?
Just trying to learn and understand

 

[TurtlePaul]

For speakers closer to 8 ohms the voltage is the limiting factor for power. For 4 ohm speakers it is the total power (voltage x current).

 

[gasolin75]

The amp play 2x160 watt 4 ohm at 1% thd peak 190 ish pr channel with a 48 5 a power supply

if your worried about not having power either get zu audio or tekton audio speakers or 2 of these amps in bridged mode https://www.audiophonics.fr/en/hifi...-ma5332m-bluetooth-50-350w-4-ohm-p-17037.html

 

[peng]

Hello Gasolin75
I thought that if the Power supply is 48V on let's say an load of 6 ohms, U/R = 48V /6 Ohms 8 Amps is requested per Loudspeaker
But Fosi is limited to 5A in total so 2.5A per channel
So per channel P=U*I =48*2.5= 120W per channel

Same with 42V , 7A requested ; but 8.5A in total, thus 4.25A per channel
So per channel 42*4.25 =178W

But effectively I didn't think about Max gain (I remember i have read 20x on Fosi V3 so yes 26dB
Can you elaborate?
Just trying to learn and understand

The more expensive Audiophonics 48 V 7.3 A is obviously better than the Fosi 48 V 5 A, all else being equal (meaning the specs are verifiable and are measured under the same conditions and according to the same applicable standards).

As far as your calculations go, you may or may not benefit from the 7.3 A vs the 5 A because it depends on your speaker's impedance characteristics, and the contents you are listening to, though given the choice, I would always take the one rated for higher current, when the rated voltages are the same.

 

[TurtlePaul]

Amir is being coy when describing the Fosi 48V supply. To be clear - the test shows it outputting closer to 7 amps. I don’t think you get anything going with the Audiophonics supply unless it is similarly very conservative in the rating.