Fosi Audio V3 HiFi Stereo Power Amplifier with TPA3255 Chip opinions?

[Trell]

Sword, appreciate the answer. Yes, I do disagree and you're welcome to disagree with me too. I have no motivation to try to convince anyone of any conclusion other than gather more information for myself. Prior to me playing with op amp swapping, I'd already read the opinions of those who say it makes no difference and those who said otherwise.

It's because of that, I bought several amps and many different op-amps to test it out for myself. I can distinctly tell differences in sound stage between op amps, I can distinctly tell differences clarity and other characteristics.

For low budget IC amps, yes, for the most part they are neutral, and hard to distinguish between one another. For that reason I would not bother. When you get into discrete op amps or different higher priced ones, you can distinguish between clarity in leading edges, sound stage characteristics as well as others. Some of those sound characteristics can be explained by FR charts, but not everything.

Whether you agree or not, if an end user perceives a difference, and that difference is worth the expense, then that's their prerogative. No one said that you have to agree or do the same. If you don't hear it, then it's not worth it. My mother could care less if she listened to a song on a crappy phone speaker, than through a high end system. Not worth it for her.

Regardless of what type of listening test you do, we're talking about perceivable differences from the human ear. In this way, it's never going to be perfect - so trying to "science it" is not very productive in my opinion.

We all have different hearing ability. It also matters how "trained" your ears are. I'm not saying you need golden ears, but someone who is not trained to look for certain attributes may not notice them.

Even if you show the same painting of a house to 2 different people who have 20-20 vision and ask them to describe what they see, you may get different responses. They both may say a house. The person who has trained to analyze artwork may tell you much more - like the the name of the artist, based on the color palette used, or the style of brush strokes, etc. A noob would not make any of those inferences even though they are looking at the same image unless they were taught to do so.

Again, I don't care to convince anyone here, this if for my own peace of mind. Thus far I have not heard any convincing, logical, scientific arguments for what I am hearing - other than I am audio fool and this opamp swapping is BS. Very dismissive.

It's a complete logical fallacy to say if YOU can't measure it, then it's just subjective and it does not exist. It could mean (but not necessarily) that you just haven't discovered the right testing method to measure that characteristic. It could mean that existing testing methods are incomplete.

Think 3 blind men and an elephant.

I've yet to see a spec sheet of an op-amp show a "measurement" of a sound stage, but from my personal experience and it seems many others, they can discern a difference between the soundstages of op amps, clearly and consistently.

Are we all just fools? Or is it just easier to name call when we can't explain what does not fit into our own cognitive bias limit of knowledge.

He did tell you about how to do listening tests to check that you actually can hear a difference.

 

[Swerd]

Sword, appreciate the answer. Yes, I do disagree and you're welcome to disagree with me too. I have no motivation to try to convince anyone of any conclusion other than gather more information for myself. Prior to me playing with op amp swapping, I'd already read the opinions of those who say it makes no difference and those who said otherwise.

It's because of that, I bought several amps and many different op-amps to test it out for myself. I can distinctly tell differences in sound stage between op amps, I can distinctly tell differences clarity and other characteristics.

For low budget IC amps, yes, for the most part they are neutral, and hard to distinguish between one another. For that reason I would not bother. When you get into discrete op amps or different higher priced ones, you can distinguish between clarity in leading edges, sound stage characteristics as well as others. Some of those sound characteristics can be explained by FR charts, but not everything.

Whether you agree or not, if an end user perceives a difference, and that difference is worth the expense, then that's their prerogative. No one said that you have to agree or do the same. If you don't hear it, then it's not worth it. My mother could care less if she listened to a song on a crappy phone speaker, than through a high end system. Not worth it for her.

Regardless of what type of listening test you do, we're talking about perceivable differences from the human ear. In this way, it's never going to be perfect - so trying to "science it" is not very productive in my opinion.

We all have different hearing ability. It also matters how "trained" your ears are. I'm not saying you need golden ears, but someone who is not trained to look for certain attributes may not notice them.

Even if you show the same painting of a house to 2 different people who have 20-20 vision and ask them to describe what they see, you may get different responses. They both may say a house. The person who has trained to analyze artwork may tell you much more - like the the name of the artist, based on the color palette used, or the style of brush strokes, etc. A noob would not make any of those inferences even though they are looking at the same image unless they were taught to do so.

Again, I don't care to convince anyone here, this if for my own peace of mind. Thus far I have not heard any convincing, logical, scientific arguments for what I am hearing - other than I am audio fool and this opamp swapping is BS. Very dismissive.

It's a complete logical fallacy to say if YOU can't measure it, then it's just subjective and it does not exist. It could mean (but not necessarily) that you just haven't discovered the right testing method to measure that characteristic. It could mean that existing testing methods are incomplete.

Think 3 blind men and an elephant.

I've yet to see a spec sheet of an op-amp show a "measurement" of a sound stage, but from my personal experience and it seems many others, they can discern a difference between the soundstages of op amps, clearly and consistently.

Are we all just fools? Or is it just easier to name call when we can't explain what does not fit into our own cognitive bias limit of knowledge.

There is no objective measure of soundstage precisely because it's an illusion. Its perception is the product of two ears connected by a human brain. It disappears completely with one speaker, one ear, or with a mono signal.

You have convinced me only that you can gaslight yourself.

 

[Pound4PoundAudio]

There is no objective measure of soundstage precisely because it's an illusion. Its perception is the product of two ears connected by a human brain. It disappears completely with one speaker, one ear, or with a mono signal.

You have convinced me only that you can gaslight yourself.

Well if you want to use that as your proof - all hearing is a an illusion. All hearing is the perception, product of two ears connected by a human brain.

Just because it disappears with one speaker, one ear or mono does NOT mean it does not exist. It just means you need to have more sensors to more completely describe the environment and characters of what you are hearing. It's why two eyes give depth perception. With one eye, it does not mean that depth does not exist, it means you need two (for a more complete picture) of depth.

Forget recordings. Let's talk about real life. You are listening to an artist in a small coffee shop vs the same artist in a concert hall. Two actual different venues with room characteristics. To your ears, is it just an illusion? You're gaslighting yourself into believing no, they are both the same?

These forums were not what I expected. So I will peace out. Apologies for disrupting flow.

 

[PENG]

So all class D amps sound the same? Tube amps vs solid state is BS? It's just my imagination. I should have just stuck to listening to music through a clock radio because sounds the same as my $6000 amp?

Why asked questions like this, when no one has said such things? Some might have said something about a certain, specific Tube amp sounding different than a certain, specific SS amp, but no one that I can recall has said Tube amp vs SS is BS, not as a general statement without any caveat, qualifications. I assume your point about clock radio sounding the same as your $6000 amp is just humor... that requires no rebuttal.

So far no proof has been provided, just highly emotionally charged insults for those who don't share the same opinion. Maybe I made a mistake - this is all emotionally, charged toxic talk and not fruitful discussion.

I thought you came here to have a discussion. Now who's getting "all emotional.., toxic talk... etc."? I would suggest you re-read the posts that you might have been offended by, and tried to focus on the substance and ignore any "emotional", toxic stuff that you perceived. May be then we can continue to enjoy a fruitful discussion. It's a hobby forum, aside from the audio, electrical science parts, no need to get upset.

 

[ben_]

Why asked questions like this, when no one has said such things? Some might have said something about a certain, specific Tube amp sounding different than a certain, specific SS amp, but no one that I can recall has said Tube amp vs SS is BS, not as a general statement without any caveat, qualifications. I assume your point about clock radio sounding the same as your $6000 amp is just humor... that requires no rebuttal.

This is someone defending changing perfectly functional op amps like it could possibly make a positive difference. The argument is either from sheer delusion, or bad faith. Nobody is comparing anything to a clock radio. If P4PA wants to waste their time chasing this down, I don't see the point in trying to dissuade them.

 

[mtrycrafts]

... It's just my imagination. ....

Well, it very well could be unless you can demonstrate audible differences under credible, controlled DBT listening with statistically significant outcome.
Until then, who knows. Subconscious biases exist as does placebo effects.

 

[mtrycrafts]

....

The first principle of scientific inquiry is that you must not fool yourself – and that you are the easiest person to fool. – Richard Feynman, Nobel Prize winner in physics

Might as well include Carl Sagan with his speech of something similar.

oh, he calls: don't leave your baloney detection kit at home....

 

[mtrycrafts]

Why stop at chip replacement? Lots of other components should be on that chopping block.
Hell, replace everything.

 

[TLS Guy]

This is someone defending changing perfectly functional op amps like it could possibly make a positive difference. The argument is either from sheer delusion, or bad faith. Nobody is comparing anything to a clock radio. If P4PA wants to waste their time chasing this down, I don't see the point in trying to dissuade them.

The point is not dissuading them. As G.K. Chesterton pointed out a long time ago, "that if you argue with a lunatic, you will always get the worst of it." The issue is maintaining the integrity of this site.

This hobby has been to a large extent highjacked by people who spout arrant nonsense that is nothing less then superstition. This encourages the ill informed to spend large sums of money on products of not only zero benefit, but even negative benefit. Their money could much better be allocated elsewhere with great benefit to them.

Achieving good results in AV has to be based on good engineering from good science and research. Basing it on nothing more then superstition is actually feeding the profit of those who are in essence scammers. So we will confront this nonsense vigorously and hopefully guide interested members to better audio and AV without breaking the family finances.

So, I personally will not tolerate the absolute garbage spouted by Pound for Pound Audi. A more appropriate handle for him would be Pounds Flushed Down the Drain.

 

[ben_]

So, I personally will not tolerate the absolute garbage spouted by Pound for Pound Audi. A more appropriate handle for him would be Pounds Flushed Down the Drain.

Garbage is an apt word. I guess I can see the point of responding to this idiocy if only to dissuade others who might stumble on it later. The intellectual equivalent of posting signs around the perimeter of a minefield.

 

[Swerd]

Why stop at chip replacement? Lots of other components should be on that chopping block.
Hell, replace everything.

I don't think anyone has tackled the question over the sound qualities from solder. Do different solder compositions matter? Lead-free solder? What about 4% silver solder? What about different brands? What about brands of soldering irons?

 

[Swerd]

The point is not dissuading them. As G.K. Chesterton pointed out a long time ago, "that if you argue with a lunatic, you will always get the worst of it." The issue is maintaining the integrity of this site.

I like a more pithy version of Chesterton's words.

Never wrestle with a turd. It doesn't matter if you win or loose, you still end up covered with sh!t.

This hobby has been to a large extent highjacked by people who spout arrant nonsense that is nothing less then superstition. This encourages the ill informed to spend large sums of money on products of not only zero benefit, but even negative benefit. Their money could much better be allocated elsewhere with great benefit to them.

Achieving good results in AV has to be based on good engineering from good science and research. Basing it on nothing more then superstition is actually feeding the profit of those who are in essence scammers. So we will confront this nonsense vigorously and hopefully guide interested members to better audio and AV without breaking the family finances.

That's why I decided to take P4P on. He could have said his listening preferences weren't scientifically determined, and I would have politely ignored him. But he went on … and on … about how certain he was about the results of his un-scientific A-B listening tests.

Yes, he's entitled to his own opinions. But if he claims that he's certain about the results on an internet audio forum, he better be able to defend his claims. When I questioned his methods, he chose to be offended and backed out. That will be there for all future readers to see.

 

[mtrycrafts]

I don't think anyone has tackled the question over the sound qualities from solder. Do different solder compositions matter? Lead-free solder? What about 4% silver solder? What about different brands? What about brands of soldering irons?

You haven't been to other chat boards in the past?
Indeed, solder has come up a number of lengthy exchanges. Good memory refresher.

 

[TLS Guy]

You haven't been to other chat boards in the past?
Indeed, solder has come up a number of lengthy exchanges. Good memory refresher.

Yes, and all spouted by people who have never made a solder joint in their lives, and would have no clue how. Would not be surprised if they picked the iron up by the hot end and blamed the solder.

 

[MrBoat]

lol. . . damn! Y'all need to smoke what grows, till you can't feel yer toes! What #4# said wasn't really that serious and certainly didn't deserve such harsh rebuttals. This conversation certainly could have went more constructively.

I mean, I have electronics in my background and if I adhered to the absolutes of all this, I'd be slap bored to death with it all. I have built and repaired a few amps in my time, and each time, I wasn't after any certain improvement. What I was after was, listening to music from an amp I built or fixed myself. It's right up there with catching fish from a boat I built myself, and the satisfactions I get from all my other DIY adventures that adds uniqueness to my life. I have knives I have made that I swear stay sharper for longer than any of their mass engineered counterparts.

These days, things have gotten to be a bit too plug and play, right down to the food we eat. We have people taking full craftsman's credit for stuff that a computer cut out for them, and assembled from predetermined bolt-on parts off of some shelf and even the design was mostly aided by some electronic brain. People that mod things just want to have some physical input, that technology has otherwise taken away. I bought perfectly performing RC cars, stripped them all down and rebuilt them into something that was more mine without involving any software. The RC hobby is mostly comprised of people modifying things and the enjoyment they get from that is where the actual value ends up being.

If y'all want to be bitter, or chasing integrity, aim it at the con artists that are charging $10-100k for a pair of 5" bookshelf speakers and about every other outrageous claim that this hobby has around it, including much of which that science tends to support, albeit loosely, and otherwise inaudibly. There's a heck of a lot more BS in the mainstream marketing of all this, than there is with people daydreaming improvements with sub $100 amps. These cheap products are perfect, low risk areas to do this.

 

[PENG]

Yes, and all spouted by people who have never made a solder joint in their lives, and would have no clue how. Would not be surprised if they picked the iron up by the hot end and blamed the solder.

Also, by their logic, no one would ever buy any of your favorite Peter Walker amps or any of audio devices designed by him because Mr. Walker admitted he/they never listened to his amps through manufacturing. They only do listening tests on distortions, funny noises etc., but not to program material and tune the circuitry, etc.. That sounds logical, based on know science, whereas the likes of P4PA's are totally illogical, makes no sense from science standpoint.

People like P4PA seem to be suggesting that the reasons why comparable devices that offer specs that indicate no audible difference to humans, sound different because there are things, metrics, that matter to audible sound quality, but their designers, manufacturers could not identity such metrics, and/or have no way of measuring them, and/or don't measure them for whatever reasons, or they designed, build their amps, devices by ears, why spend huge amount of time and other resources to vary different parts, components, circuitry, to achieve the kind of "sound" that people such as P4PA perceived (whatever they may be).

 

[mtrycrafts]

... that people such as P4PA perceived (whatever they may be).

And, what about the next person that hears something different?
Conclusion, design an amp for each person's desire.
Boy, who would pay of all those individual designs? Who would do it in the first place.

 

[MrBoat]

Feeling all warm and Fosi.

Tascam CD player into, and using the Aiyima HPA for tone controls, into the Fosi V3, and I have that hooked to the Fosi BT30D Pro as a subwoofer amp. 48v Meanwell supply turned down to around 46V. No hiss or hum anywhere. Sounds quite good.

 

[mlieber507]

There are some objective quality differences between the NE5532 Op Amp that, I think is in an A07, and some other Op Amps. One of these is slew rate. Op Amps with higher slew rates than an NE5532 should provide better transient response and thus, lower transient intermodulation distortion (TIM}. TIM levels are mostly independent of THD and TIM is noticeable to the human ear. If you listen to high dynamic range music at fairly high volume levels a TL072 could provide audible benefits.

 

[Trell]

Here we go again.