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Fosi Audio V3 Mono Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 7 1.5%
  • 2. Not terrible (postman panther)

    Votes: 11 2.3%
  • 3. Fine (happy panther)

    Votes: 95 19.9%
  • 4. Great (golfing panther)

    Votes: 364 76.3%

  • Total voters
    477

DavidM1

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More on OpAmps, live review of ZA3 by @VirtualHiFi
Sound difference between stock opamps and Sparkos night and day, in my opinion, and that of many others too.

Fosi ZA3 + Sparkos Op-amp - The real deal - Don't miss out !!! Interested in Sparkos Opamps - visit www.sparkoslabs.com

"Fosi is a great little amp that can put many multiple thousand $$$ to real shame. The TPA3255 which is a heart of this amplifier is my favorite D-class Amp chip. It's dynamic, fast and tight, but also has the most wonderful midrange that I like even more than most class AB amps. So how about upgrading it with one of the finest Op-amps - Sparkos Labs SS3602. This is a fully discrete op-amp and the combo is amazing. What's better than me saying it ? You being able to hear it yourself."

In this video is a demo of the Fosi ZA3 with standard opamps and with Sparkos Labs SS3602.
Over 20 minutes of sound demo for you across different genres so that you can enjoy and make up your mind :)
0:00 - The Sparkos & The Fosi
2:41 - How to replace the Op-amps
10:27 - One more trick - even less Op-amps needed ;)
14:15 - All that you are - Elvin Vanguard
15:45 - Purple Beach - Giants’ nest
17:15 - Monsoons - Johannes Bornlof
18:45 - The Last Kiss - Ritchie Everett
20:15 - Love You For It All - Daniel Gunnarsson
21:45 - Wood & Skin - Hara Node
23:15 - Something new - Anthony Lazaro feat Sarah Kang (Korean Version)
24:45 - Folium - Bladverk Band
26:15 - Air on the G String - Johannes Bornlof
27:45 - Coming Home Blues - Bo the Drifter
29:15 - Intimacy - Alex Kehm
30:45 - I Am Better Off (Jazz version) - Wildson
32:15 - Wandering Nomad - Cody Francis
33:45 - Virga - Bladverk Band
35:15 - The One - Ritchie Everett
36:45 - Conclusions

I think a very easy blind test is to simply close your eyes and see if you can identify when the op amp has changed. Another would be to cover the screen and run your finger randomly along the time bar. If you can consistently pick the correct amp from its sound alone then you definitely have a case.
 

somebodyelse

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Yes, there is no doubt that we tend to prefer higher gain when doing a comparison.
See also the section on the 'Wason effect' (best tried on headphones):
There is no 'Wason effect' - it's a demonstration of confirmation bias prompting people to 'hear' a difference where there isn't one. This is why we need to test with all cues removed, visual or otherwise.
 

SMen

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See also the section on the 'Wason effect' (best tried on headphones):
There is no 'Wason effect' - it's a demonstration of confirmation bias prompting people to 'hear' a difference where there isn't one. This is why we need to test with all cues removed, visual or otherwise.
That's very good thank you. Also the bit about the masking, and our ability to 'fill in'. I've often thought this ... but funnily enough it also makes me think that 'quick switching' between two options has its weaknesses too. Our brains are trying their best to interpret the sounds we hear and the thought process "changing op amps is a load of rubbish" is in itself an influencer.

This is probably why this is such a thorny issue (e.g. op amps) between different points of view. But heck ... I listen to records :D!!
 
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somebodyelse

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That's very good thank you. Also the bit about the masking, and our ability to 'fill in'. I've often thought this ... but funnily enough it also makes me think that 'quick switching' between two options has its weaknesses too. Our brains are trying their best to interpret the sounds we hear and the thought process "changing op amps is a load of rubbish" is in itself an influencer.
Not hearing something you should be able to is another demonstrated form of confirmation bias, and should be accounted for in good test design. You'll see this in the good published studies. It's not so easy with self-administered tests though. I think quick switching being more sensitive (among other things) is covered in https://www.audiosciencereview.com/...d-testing-you-are-doing-it-wrong-video.26809/ - there's nothing stopping you doing slow blind tests but the evidence is they're less likely to show differences. Anything further is going to take us well off topic into that thread or https://www.audiosciencereview.com/...are-measurements-everything-or-nothing.29062/
This is probably why this is such a thorny issue (e.g. op amps) between different points of view. But heck ... I listen to records :D!!
So do I! At least with records it's easy to show that small adjustments make a measurable difference, often plenty big enough to hear ;)
 

YesChickenNuggets

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See also the section on the 'Wason effect' (best tried on headphones):
There is no 'Wason effect' - it's a demonstration of confirmation bias prompting people to 'hear' a difference where there isn't one. This is why we need to test with all cues removed, visual or otherwise.

Cool post somebodyelse, but I the nuggets, was not tricked at all. I was exceptionally confident I heard absolutely no difference. :p

I also did the opamp mod to the lm in my v3 and ayima vanilla, no perceptual difference. I knew that would probably happen going in, but I felt like one of the cool kids.
 
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YesChickenNuggets

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Oh the old "night an day" story again.
In fact it is Sparkos trying to cash in on the V3mono hype by pulling the fomo trigger.
I've been following the sparkos mythos for a long time. While I do believe they're better opamps, the way they're marketed is kind of, IDK.

olieb, do you think they're a bit disingenuous in the way they push the product?
 

SMen

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Not hearing something you should be able to is another demonstrated form of confirmation bias, and should be accounted for in good test design. You'll see this in the good published studies. It's not so easy with self-administered tests though. I think quick switching being more sensitive (among other things) is covered in https://www.audiosciencereview.com/...d-testing-you-are-doing-it-wrong-video.26809/ - there's nothing stopping you doing slow blind tests but the evidence is they're less likely to show differences. Anything further is going to take us well off topic into that thread or https://www.audiosciencereview.com/...are-measurements-everything-or-nothing.29062/

So do I! At least with records it's easy to show that small adjustments make a measurable difference, often plenty big enough to hear ;)
Another good link thank you! In an earlier post I was half serious that indeed these dual monos might not be a bad way to blind test op amps... so sort of getting it back on topic!

Listening to Amir's "suggestion section" of his video, I'm glad to say I was thinking I might get my 7 year old to log the results! ... and indeed to do false switches to catch me out!

All good fun ... listening tests are permitted so long as we do them right! Thank heavens for records ... I'm left completely 'meh' by most swaps between the few dac's I have lying around and those are complete units ... not op amps ... never mind the filters they put on these things. So context is everything. If I'm straining to hear an improvement ... I don't bother.

I'm going to be interested to hear if these have me enjoying a sense of dynamics at lower volumes ... my reason for getting these, and to compare to another unit I have which I modded.
 

EddNog

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There’s also the concept of stacked changes. Individual changes may not be large enough to be perceptible on their own, but adding them together may grant an audible overall change. Let’s take a theoretical example where someone built a chain with Fosi DAC, Fosi preamp, and Fosi power amps. Let’s say all three components offer rollable op-amps. Now let’s say that just testing op-amp changes for each component one at a time yields inaudible differences. What if rolling all the op-amps in all three components to the same aftermarket type is done and then the entire chain is compared stock versus all three rolled. Would the change then be audible? Too many variables to consider, of course, but one who is prone to rolling op-amps in one part will almost certainly tweak every component they can, no? And that’s something to consider. For fellow cyclists, this would be analogous to Team Sky’s strategy of, “marginal gains.”

-Ed
 

SMen

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Sorry, looks like I miss something here. It would be great if you can give me some insights about it.

I believe that if we change anything (e.g the Op Amps) on the signal path, the audio output would be different for sure.

The question is audible or not. Based on some measurements, we could get some idea about it. It is always interesting to know the result.

Let's assme the measurements indicate it is highly unlikely to hear any difference (e.g. with 95% confidence level) but someone claims that he really experience the difference. Can these two co-exist without any conflict? Looks to me it is ok as the hearing experience is his own feeling. Correct?
I'm not sure they can co-exist harmoniously (pun intended). But I'd like to think an engineer would test more to validate, and a listener would challenge their own experience by checking levels, getting someone to switch while they listen blind ... or make things as random as possible.

The thing is, by the time you have switched op amps and plugged everything back in you have slightly lost the plot (or I have). With these doing dual tests in mono you could really switch ... and test your experience with different op amps to establish one way or another (for you).
 

Yorkshire Mouth

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There’s also the concept of stacked changes. Individual changes may not be large enough to be perceptible on their own, but adding them together may grant an audible overall change. Let’s take a theoretical example where someone built a chain with Fosi DAC, Fosi preamp, and Fosi power amps. Let’s say all three components offer rollable op-amps. Now let’s say that just testing op-amp changes for each component one at a time yields inaudible differences. What if rolling all the op-amps in all three components to the same aftermarket type is done and then the entire chain is compared stock versus all three rolled. Would the change then be audible? Too many variables to consider, of course, but one who is prone to rolling op-amps in one part will almost certainly tweak every component they can, no? And that’s something to consider. For fellow cyclists, this would be analogous to Team Sky’s strategy of, “marginal gains.”

-Ed

Yes, but Team Sky’s marginal improvements are all definitely, provable improvements, just too slight on their own. Lots of slight improvements add up to something worthwhile.

Lots of non-existent improvements add up to nothing. Lots of very, very, very, very slight improvements add up to one very slight improvement which may not be noticed by your ears, but definitely will be by your bank manager.

Just a different perspective.
 

Talisman

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@AdamG Would it be possible to create a dedicated thread for replacing opamps? Because this thread is really terribly watered down by a topic that is only of interest to some and which essentially has little to do with the fosi v3 mono itself
 

SMen

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@AdamG Would it be possible to create a dedicated thread for replacing opamps? Because this thread is really terribly watered down by a topic that is only of interest to some and which essentially has little to do with the fosi v3 mono itself
Maybe when the units arrive the dual mono experiment could be in that kind of thread. ... but the fosi does come with replaceable op amps ... and they are suggesting something I just don't get which is replacing single op amps in a parallel configuration ... and that is all very relevant to the fosi v3 mono itself.
 

AdamG

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@AdamG Would it be possible to create a dedicated thread for replacing opamps? Because this thread is really terribly watered down by a topic that is only of interest to some and which essentially has little to do with the fosi v3 mono itself
Yes it is possible. We need the people involved in this Op Amp conversion to go create a separate thread where they can talk about as much and long as they want.

What we can do to facilitate this is to notify them that these off topic posts about Op Amps will be deleted and if they persist then they will have their posting privileges revoked. Please report any further Op Amp posts in this thread.

Thank you for your cooperation and understanding. ;)
 

AdamG

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and that is all very relevant to the fosi v3 mono itself.
It may be relevant to the Amp itself but it is not relevant to this particular Review and Test. So please start a new separate thread. This is a Official Review thread.
 

Talisman

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Maybe when the units arrive the dual mono experiment could be in that kind of thread. ... but the fosi does come with replaceable op amps ... and they are suggesting something I just don't get which is replacing single op amps in a parallel configuration ... and that is all very relevant to the fosi v3 mono itself.
It is only relevant to people interested in this, and I suspect they are not the majority on this site.
I think most people just want to make sure they get the (very good) performance of the original tested design with the components installed by default.
 

Alex_Brouwer

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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."
Would 2 5amp psu's make a difference compared to 1 10amp?
 

Elvom

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How did I miss this?
- the video that we all want to see :)
Maybe im deaf but its really hard to tell a any difference on all comparisons with hd800 headphones or with Kef r3 speakers, and if im not looking at the screen i dont even notice when the equipment switches
 
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