Fosi Audio V3 Mono Amplifier Review

[YesChickenNuggets]

See also the section on the 'Wason effect' (best tried on headphones):

Spoiler: Explanation if you don't want to watch the video

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.

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.

 

[YesChickenNuggets]

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]

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.

 

[Deleted member 72219]

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]

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]

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]

@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]

@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]

@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]

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]

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.

 

[Negatywny]

so the last post in regard of opamps. Fosi, can objective science believers get e. g. another t-shirt instead of useless muses opamp?

 

[Alex_Brouwer]

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]

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

 

[AdamG]

Multiple Off topic posts deleted and 2 week thread bans issued as promised in post 1156 above.

 

[yuki]

It would be great if you could put two of these amps inside the LC30 case!
My ramblings aside, thanks for the great amp!

 

[sl1982]

I am wanting to hook a pair of these up to my AVR. Its a yamaha RX A770. It doesnt have any preouts for the mains. Only for zone 2. Would something like this work acceptably to convert the speaker level output to a preamp level? https://www.audiocontrol.com/car-audio/factory-system-upgrade/lc1i/

 

[Elgrosso]

It would be great if you could put two of these amps inside the LC30 case!
My ramblings aside, thanks for the great amp!

They won’t fit, but the stereo version does

 

[staticV3]

I am wanting to hook a pair of these up to my AVR. Its a yamaha RX A770. It doesnt have any preouts for the mains. Only for zone 2. Would something like this work acceptably to convert the speaker level output to a preamp level? https://www.audiocontrol.com/car-audio/factory-system-upgrade/lc1i/

Having the Yamaha's Line level signal be amplified by the built-in Amp, then brought back down to Line level via the adapter, then once again amplified to Speaker level by the Fosi, sounds extremely inefficient.

Instead, I'd try to modify the Yamaha by adding RCA Line outputs myself.

There's a service manual available online which guides you through the disassembly process and contains detailed block diagrams and PCB schematics.

 

[Rafaille]

I am wanting to hook a pair of these up to my AVR. Its a yamaha RX A770. It doesnt have any preouts for the mains. Only for zone 2. Would something like this work acceptably to convert the speaker level output to a preamp level? https://www.audiocontrol.com/car-audio/factory-system-upgrade/lc1i/

Why not use zone 2 line out?