Fosi Audio V3 Amplifier Review

[Joe Smith]

yeah, i read about it later. but V3 is great as it is, dont see where is this PFFB noticeable in general use. Is there an actual audible difference to sound output, or this is just spec war.

I like the sound of the V3 just fine...using at present with some Elac Debut 6.0 speakers. I think for people with speakers that lean even further towards a bright sound, the rise in high frequencies may be an annoyance. For me, with my hearing top end at about 12khz, it's not a factor. If you look at Amir's graphs, the difference is pretty slight. The V3 has about +1 db at 20khz, the new mono amps about +.5 to .6 db at 20khz. Fosi had posted a revised graph that shows even less of a rise, which is cool. I think that's what they need to do for these to be considered competitive with the lower range of Hypex-based amps.

The other issue/improvement would be if one wants more power than the V3 can offer. Again, not a factor for me, as I'm using with a 36v power supply and it's plenty loud for our smaller room applications.

 

[doug s.]

yeah, i read about it later. but V3 is great as it is, dont see where is this PFFB noticeable in general use. Is there an actual audible difference to sound output, or this is just spec war.

if you look at frequency response and impedance graphs of speakers, you can determine if an amp w/o pffb will make a difference in your speakers. in the majority of cases, the answer will be no. the impedance of the speaker needs to be really high (or low) to affect the speaker's output - it will increase or decrease depending on the speaker's output being above or below 8 ohms at high frequencies. and even if the response is increased (or decreased) a db or two above, say, 10khz, most people will not be able to hear a difference. re: the improved distortion levels, there's no way you could hear the difference as distortion levels are already below audibility.

doug s.

 

[somebodyelse]

yeah, i read about it later. but V3 is great as it is, dont see where is this PFFB noticeable in general use. Is there an actual audible difference to sound output, or this is just spec war.

I suspect the noise and distortion difference won't be audible. Load dependency may be, depending on the load. See Erin's tests of the za3 or Wiim Amp to see the 0.5dB peak at ~2kHz produced by a 20R impedance peak for an example of why it may be audible even to the older population. Some speakers have more extreme impedance swings that would produce larger changes, others not so much, so you would need to check. You can correct for it with filters - say the PEQ in the Wiim Amp.

 

[gasolin75]

Fosi Audio V3 Mono Amplifier Review

This is a review and detailed measurements of the Fosi Audio V3 Mono class D amplifier. It was sent to me by the company. The price with the power supply I tested is US $139.99. I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime...

www.audiosciencereview.com

 

[Kimbrough Xu]

yeah, i read about it later. but V3 is great as it is, dont see where is this PFFB noticeable in general use. Is there an actual audible difference to sound output, or this is just spec war.

Most people can not hear the difference, even in comparison test, as myself, I can not sense the 0.5dB difference. And different speakers have different impedances, it also depends on your speakers.

 

[G-Can]

so to conclude, not worth the hassle for someone who owns V3 and ZA3 lol

 

[-Jim-]

so to conclude, not worth the hassle for someone who owns V3 and ZA3 lol

This is a very decent Mono amp at this price point, and suitable for new systems and the delta isn't worth it for folks who already own a V3 or similar. But going forward, I expect this would be a leading candidate to evaluate if one wanted to build something up with Class D Mono Block Amps.

 

[G-Can]

This is a very decent Mono amp at this price point, and suitable for new systems and the delta isn't worth it for folks who already own a V3 or similar. But going forward, I expect this would be a leading candidate to evaluate if one wanted to build something up with Class D Mono Block Amps.

I get the proper mono block amps, due to their size and power, so they would be really big to have them in one enclosure.

But I trully dont see why this would exist as a solo amp, or they need to just make a 2ch straight power amp, like combining two of these in one enclosure.

 

[burkm]

A mono amp has for multichannel applications its advantages, or how would you power the 3-channel front arrangement (L,C,R etc.) ?
This is one of the many advantages a single channel (mono) may have...

 

[G-Can]

A mono amp has for multichannel applications its advantages, or how would you power the 3-channel front arrangement (L,C,R etc.) ?
This is one of the many advantages a single channel (mono) may have...

how? with something made for it, less cables, less power bricks, less mess, as in
https://www.audioholics.com/amplifier-reviews/monoprice-m5100-amp

To buy 3 x mono V3, it will cost you over $400, I would spend extra few $ to buy a dedicated 3ch amp.

single box with built in power supply, and way less cables and mess, then 3 x V3.

And in my experience, V3 is actually not good for HT use, at least original V3. It sounds like crap comapred with my AVR output dut to low gain or something, I was explained.

 

[C0mbat]

I see that the Kickstarter campaign will provide two options. One with a single power supply and one with two power supplies. I'm easily able to hide my power supplies so would there be any sonic benefit in getting two or should I stick with one? I don't play my music above 75db and I'm only feeding the signal above 85hz to them as I'll be using the high pass filter on my Kef KC62 sub.

 

[Sokel]

Quick question, would it be better to have the volume control in Windows 11 set to 100% and then control the volume through the Fosi V3 amp, or can I just leave the amp at maximum volume and control it through Windows?

Depending of your set-up,I would read this one first:

Ending the Windows Audio Quality Debate

A debate has been long raging in the audio community that Windows isn't fit for use in a high resolution audio system. Sceptics counterargued that bits are bits and Windows audio degradations are a figment of an over-active audiophile imagination. I decided to investigate this as I kept...

www.audiosciencereview.com

It might need to be a tad lower to avoid stuff.

 

[Kimbrough Xu]

I see that the Kickstarter campaign will provide two options. One with a single power supply and one with two power supplies. I'm easily able to hide my power supplies so would there be any sonic benefit in getting two or should I stick with one? I don't play my music above 75db and I'm only feeding the signal above 85hz to them as I'll be using the high pass filter on my Kef KC62 sub.

Then just one 48V 5A is enough.

 

[soundaholic]

Then just one 48V 5A is enough.

@C0mbat in this review (starting at around 3:00 min) it was recommended to go with two power supplies due to "strange noises".

 

[Toku]

@C0mbat in this review (starting at around 3:00 min) it was recommended to go with two power supplies due to "strange noises".

There is no problem even if you supply two V3 Monos from a 48V 10A power supply. The noise occurring in the video footage may be due to other causes.

 

[Kimbrough Xu]

@C0mbat in this review (starting at around 3:00 min) it was recommended to go with two power supplies due to "strange noises".

Can keep an eye on their final version.

 

[Falco]

I ordered this little amp for the play room of my boys so they can play some music, quite eager to receive it...

I plan to use it with a SMSL SU-1, RPi streamer with moOde OS and some Q Acoustics 2020 speakers.
Nice that it's such a simple amplifier as my kids basically only use Spotify as music source, hope this little amp delivers.

 

[cyclo]

A mono amp has for multichannel applications its advantages, or how would you power the 3-channel front arrangement (L,C,R etc.) ?
This is one of the many advantages a single channel (mono) may have...

I have 3 x Fosi V3s powering, respectively, the stereo front channels; a center channel speaker which is bi-amp capable (Paradigm C500) so I power the treble mid input with one channel and the bass drivers input with the other channel; and the rear channel speakers. For the front channel I use the 48V/5A PSU, while for Fosi V3s powering the center and rear I use 36V/6A PSUs. I also have 2 Aiyimas powering the the ATMOS front and rear height speakers and those Ayimas are powered by the the stock 32V/5A PSUs.

Very happy with these Class D amps which actually replaced a bunch of Class AB amps on my setup.

Center channel is bi-amp capable so I use the left and right channel outputs of one V3 to power these:

 

[Eric Natural]

Just got one of these(w/orange knob & 48v natch).
My goodness, the output posts are small - what are you cats using to connect it to your/my 12 gauge wires ?

 

[Toku]

Just got one of these(w/orange knob & 48v natch).
My goodness, the output posts are small - what are you cats using to connect it to your/my 12 gauge wires ?

Usually, banana plugs are used to connect.