Fosi Audio V3 Mono Amplifier Review

[Guddu]

Hello! Dear owners of this device, do you have any pop when turning on/off this device? Thank you)

My pair of unit had and still has pop sound, informed here as well:
Thread 'Fosi v3 Mono - User Impressions | Owner's Thread'
https://audiosciencereview.com/foru...v3-mono-user-impressions-owners-thread.54043/

Amit has also noticed in the first post (towards end of it).

 

[petch]

Is it worth swapping the opamps out in the v3 mono? Ideally for something that won't break the bank to buy 4 of...

 

[MT_bassbone]

I have had a chance to listen to Fosi V3's for about a week now. I do like the Wiim Ultra/Fosi V3 Mono (x2) combo. I also have run it though the Fosi ZD3 DAC too. I like the combo with the DAC but without also sounds lovely too. I have been listening using the Totem Sttaf speakers. My concern is eventually upgrading my speakers to something like a CSS Audio 2TD-X or Blachard MLTL6 and whether the V3 mono's could power them. Tomorrow I am going to check out a Cambridge Audio CXA61 and CXA81. What are everyone's thoughts? Do you think the little class D V3's could power the CSS and MLTL6 and get the most out of them compared to a full sized class A/B amp?

 

[Guddu]

I have had a chance to listen to Fosi V3's for about a week now. I do like the Wiim Ultra/Fosi V3 Mono (x2) combo. I also have run it though the Fosi ZD3 DAC too. I like the combo with the DAC but without also sounds lovely too. I have been listening using the Totem Sttaf speakers. My concern is eventually upgrading my speakers to something like a CSS Audio 2TD-X or Blachard MLTL6 and whether the V3 mono's could power them. Tomorrow I am going to check out a Cambridge Audio CXA61 and CXA81. What are everyone's thoughts? Do you think the little class D V3's could power the CSS and MLTL6 and get the most out of them compared to a full sized class A/B amp?

CXA61 & CXA81 are rated with 60w & 80w (8 ohm load), you have power output measured for v3 mono in the first post here.
You can choose any but v3 aren’t short on power.

 

[DavidM1]

Is it worth swapping the opamps out in the v3 mono? Ideally for something that won't break the bank to buy 4 of...

Why would you bother? There are a few businesses hoping it becomes a thing but I’ve yet to see any objective improvement reported.

 

[Doodski]

Is it worth swapping the opamps out in the v3 mono? Ideally for something that won't break the bank to buy 4 of...

It's selecting a OP amp part that has no basis in science to be more compatible with the circuitry they are installed in. By the time you spend money on them and plug them in or solder them in place you may damage the PCB or peripherals and there is no guarantee that they will sound better or even different in some cases. It's guessing...

 

[Old_School_Brad]

Is it worth swapping the opamps out in the v3 mono? Ideally for something that won't break the bank to buy 4 of...

In the worst-case scenario, you could cause the amplifier to oscillate due to the circuitry not being compatible with the operational amplifier you've selected. There's a slight chance you might perceive an increased "airiness" effect as a result of the high frequency distortion that could occur.
I'd much rather advice you to use tone controls to change the sound...

 

[mike70]

I have had a chance to listen to Fosi V3's for about a week now. I do like the Wiim Ultra/Fosi V3 Mono (x2) combo. I also have run it though the Fosi ZD3 DAC too. I like the combo with the DAC but without also sounds lovely too. I have been listening using the Totem Sttaf speakers. My concern is eventually upgrading my speakers to something like a CSS Audio 2TD-X or Blachard MLTL6 and whether the V3 mono's could power them. Tomorrow I am going to check out a Cambridge Audio CXA61 and CXA81. What are everyone's thoughts? Do you think the little class D V3's could power the CSS and MLTL6 and get the most out of them compared to a full sized class A/B amp?

You're asking if the v3 are enough and you'll try the cambridges with less power?

Ok, I'm officially confused

 

[roog]

Is it worth swapping the opamps out in the v3 mono? Ideally for something that won't break the bank to buy 4 of...

When I worked in industry as an electronics designer I would select op amps based on a whole range of key parameters, I recall thinking that even the very low cost units far exceeded the needs of most of my instrumentation requirements, but invariably I would select something with lower noise provided that I didn’t compromise an electrically robust solution. The extra cost was insignificant given our low production numbers of what was a specialist product. Plus I never really thought of audio as being a particularly challenging branch of electronics design, but then I wasn’t aiming for ‘Topping’ levels of performance!

And yet in my home audio projects I would obsess over offset, slew rate, noise etc. with no real basis for my paranoia. I never heard any benefit from using what I considered to be ‘exotic’ components and certainly didn’t have access to test equipment that could reliably detect any objective benefit.

In my opinion the venerable NE5532 is pretty good.

 

[roog]

You're asking if the v3 are enough and you'll try the cambridges with less power?

Ok, I'm officially confused

I think, perhaps we should spend a little more time testing the actual power profile of our listening habits.

I am lured in by the need for ‘More-Power’ as much as the next person, however I strongly suspect that the actual need is much lower than we might think. Even with my relatively inefficient loudspeakers 100W is way more than I need.

 

[SMen]

Is it worth swapping the opamps out in the v3 mono? Ideally for something that won't break the bank to buy 4 of...

I tried the Muse02's that Fosi supplied in the Kickstarter along with another pair I have supplied with a DAC I use - tried with my vinyl set up - and the NE5532's went back in pretty quickly. I really questioned Fosi's suggestion / provision of these alternatives. I'm pretty sure @Old_School_Brad 's high frequency distortion effect was the result ... without any pleasant 'airiness'.

 

[MT_bassbone]

You're asking if the v3 are enough and you'll try the cambridges with less power?

Ok, I'm officially confused

I guess I am wondering if class a/b rated at 60 watts per channel is cleaner than class D at 100+ watts per channel especially at extreme volumes both soft and loud. The reviews seem to suggest listening at loud volume causes distortion above 85 db. Or is this a stupid question?

 

[Old_School_Brad]

I guess I am wondering if class a/b rated at 60 watts per channel is cleaner than class D at 100+ watts per channel especially at extreme volumes both soft and loud. The reviews seem to suggest listening at loud volume causes distortion above 85 db. Or is this a stupid question?

That would depend entirely on the SPL, speakers, listening distance and the music genre.

 

[MT_bassbone]

That would depend entirely on the SPL, speakers, listening distance and the music genre.

not sure how to find the SPL. My speakers are Totem Sttaf at least for now. I listen at a distance of about 12 feet away. I listen to almost everything. My room is small to medium in size. If I had to guess may be 15' x 15'.

 

[Old_School_Brad]

not sure how to find the SPL. My speakers are Totem Sttaf at least for now. I listen at a distance of about 12 feet away. I listen to almost everything. My room is small to medium in size. If I had to guess may be 15' x 15'.

You can download the NIOSH app on your phone and use it to measure the sound levels at your listening position at the maximum volume you listen at to get an idea of the levels.

 

[MT_bassbone]

You can download the NIOSH app on your phone and use it to measure the sound levels at your listening position at the maximum volume you listen at to get an idea of the levels.

I got it up to 87 db before it was uncomfortable to listen. I didn't think it was too bad. I'll report back on the Cambridge gear later today.

 

[petch]

Thanks all for the replies - I'll leave it be

 

[MT_bassbone]

I got it up to 87 db before it was uncomfortable to listen. I didn't think it was too bad. I'll report back on the Cambridge gear later today.

The Cambridge CXA61 and CXA81 were a no go. Too warm for my taste.

 

[Antlestxp]

Anyone have experience using the v3 with passive subs? I have been running a pair to power a pair of subs over the last week. They are each 4ohm dual 8inch units. Both mono's run pretty hot after a music session. Should I be worried about their longevity. I also get a pretty good "pop" when they kick on. I haven't seen that reported in any reviews.

 

[MT_bassbone]

Anyone have experience using the v3 with passive subs? I have been running a pair to power a pair of subs over the last week. They are each 4ohm dual 8inch units. Both mono's run pretty hot after a music session. Should I be worried about their longevity. I also get a pretty good "pop" when they kick on. I haven't seen that reported in any reviews.

I also get the pop out of the speakers when they power up. How are you connected to them XLR or RCA? I get of a pop with RCA.