Fosi Audio V3 Mono Amplifier Review

[Killingbeans]

So you worked in 'electronics design' - what you don't say is - was that work in the audio electronics industry, If so what companies did you work for?

Doesn't matter. Analogue signal processing is analogue signal processing.

Audio signals do not break the laws of physics, and they do not behave in any magical way.

On the contrary. Most disciplines of electronics consider the audio range to be "practically DC".

You really don't need to work with audio signals specifically in order to know what it takes to filter them effectively.

 

[Killingbeans]

air is the best dielectric.

It is. That's why it's used as the dielectric in high power RF applications, where the loss is critical. Audio electronics is not one of them.

The best connectors are no connectors.

Get yourself some active speakers with WiFi connectivity. Audio nirvana!

 

[antcollinet]

Quote - This doesn't mean you have a hearing problem - it just means that your auditory system is just the same as all humans - I've read some bllocks in my time but you get a gold medal for that. Hilarious - all humans hear the same - now go and say that face-to-face with a trained and experienced audiologist and see their reaction

Way to misunderstand what was said - you desperately need to do some work on filling in that chip in your shoulder.

First allow me to fill in the full quote to include the context you left out:

If you are hearing sound improvements from these changes, then by far the most likely explanation for this is sighted listening being subject to cognitive biases - in this case - almost certainly - expectation bias. This doesn't mean you have a hearing problem - it just means your auditory system is just the same as all humans.

Then allow me to clarify:

Your hearing is just the same as all humans IN THAT - just like everyone else - it is subject to cognitive/perceptive biases that can subconsciously alter your perception of the sound in between your ears, and your conscious brain. That actually makes your hearing unique to you - because how that bias works will be dependent on everything you have learned and experienced since the day you were born. You will literally hear different stuff than others which has NOTHING to do with the sound waves reaching your ears, and hence nothing to do with the capacitors you have just changed except in how that alters what you believe about the kit. And is not even consistent since it will change based on your mood/comfort/feelings/sobriety (etc) day to day or even hour to hour.

 

[Down South]

Doesn't matter. Analogue signal processing is analogue signal processing.

Audio signals do not break the laws of physics, and they do not behave in any magical way.

On the contrary. Most disciplines of electronics consider the audio range to be "practically DC".

You really don't need to work with audio signals specifically in order to know what it takes to filter them effectively.

So no actual experience in the audio field - exactly what I thought.

 

[antcollinet]

So no actual experience in the audio field - exactly what I thought.

But actual experience of electronic design - including understanding how and why capacitors influence the behaviour of analogue electronics.

Unlike someone who thinks swapping stuff at random without detailed consideration of the overall design is a valid way to make improvements.

Or are you able to provide the design calculations to explain how your mods interact with the overall amp design to cause the audible changes you claim they do?

 

[Down South]

Way to misunderstand what was said - you desperately need to do some work on filling in that chip in your shoulder.

First allow me to fill in the full quote to include the context you left out:


Then allow me to clarify:

Your hearing is just the same as all humans IN THAT - just like everyone else - it is subject to cognitive/perceptive biases that can subconsciously alter your perception of the sound in between your ears, and your conscious brain. That actually makes your hearing unique to you - because how that bias works will be dependent on everything you have learned and experienced since the day you were born. You will literally hear different stuff than others which has NOTHING to do with the sound waves reaching your ears, and hence nothing to do with the capacitors you have just changed except in how that alters what you believe about the kit. And is not even consistent since it will change based on your mood/comfort/feelings/sobriety (etc) day to day or even hour to hour.

Incredible, barring one word this is a very rational post. But then you drop in the magic word 'believe' You are the 'true believer' and the one with a chip on his shoulder projecting your belief syndrome on to others. You cannot possibly know how others 'hear' music, that is very arrogant but typical of the 'true believer'. I don't 'believe' music I like most other people listen to music. Indoctrination is a terrible affliction. Thought is not reality, only reality is real.

You stay with your indoctrination and I like most will continue to listen to music in the moment because that is where music exists.

 

[rvsixer]

Sorry for bothering you for nothing, I asked exclusively for V3M.

Judging by your response, it appears you may have missed (or not bothered looking at) the V3M specific info source I referenced to help you with your question. Good luck.

 

[rwnano]

I have a pair of Irving M Bud Fried SIgnature A 6 transmission line speakers, 2 way, 89 dB sensitivity. I like their sound with my Harman Kardon AVR 3550 - 28 Amperes high current capacity. 65 Watts RMS in 8 Ohms, which is likely 100 Watts out the door.

I'm getting a class AB dual monoblock - 195 Watts * 8 Ohms Stereo amplifier.

How will it compare in sound to Fosi v3 twin monoblocks?
Should I go in for it? will it sound much better? Thank you for your opinions!

 

[avdoc]

I have a pair of Irving M Bud Fried SIgnature A 6 transmission line speakers, 2 way, 89 dB sensitivity. I like their sound with my Harman Kardon AVR 3550 - 28 Amperes high current capacity. 65 Watts RMS in 8 Ohms, which is likely 100 Watts out the door.

I'm getting a class AB dual monoblock - 195 Watts * 8 Ohms Stereo amplifier.

How will it compare in sound to Fosi v3 twin monoblocks?
Should I go in for it? will it sound much better? Thank you for your opinions!

There's no way to predict how it will sound. I purchased the V3M because I wanted a good sounding small amp with an efficient design at low cost. The Fosi has exceeded my expectations. While they're not perfect (I randomly get turn-on thump through my speakers, the amps run hot, and the power blocks were challenging to hide), the size/price/performance ratio are tough to beat.

 

[jbaumann]

@Down South, without trying to be condescending, I get definite Dunning-Kruger vibes here.

Please allow me to fill in some basics:

Read about the Nyquist-Shannon-theorem and its ramifications. A good starting point is https://en.m.wikipedia.org/wiki/Nyquist–Shannon_sampling_theorem. But beware, from reading it to really grokking it is quite a bit of a distance, you have to understand a lot of physical basics (and again, I don‘t mean simply having read about it once). In my eyes, Nyquist-Shannon is one of the most misinterpreted and misunderstood theorems.

Then, please read one of the classics, „The Art of Electronics“ by Horowitz and Hill. Please start with Section 1, Foundations, then Section 6, Filters, followed by Section 8, Low-Noise Techniques. Read other sections as required.

The next book I would suggest is another of the classics, „Microelectronic Cirquits“ by Sedra & Smith. Part II especially focuses on amplifier design (including feedback circuits, which is important for the V3).

For class D amplifiers you have to additionally understand how pulse-width-modulation works (we ignore the input stage) and the crucial role of the output filter and thus the Nyquist-Shannon-theorem. For a first overview, Wikipedia is actually ok, but follow the literature recommendations: https://en.m.wikipedia.org/wiki/Pulse-width_modulation

As soon as you have really understood this basic literature you will see that e.g. @antcollinet and others are simply trying to help, and are pretty much spot on in what they are saying.

If you need more pointers to relevant literature, please ask. Many more here will be able to provide many more books and papers.

 

[antcollinet]

How will it compare in sound to Fosi v3 twin monoblocks?

It will be indistinguishable - or so close to indistinguishable as not to matter IF you are playing within the power window of the Fosi - which is a bit less than your proposed monoblocks. With your 89dB sensitivity speakers though, this seems pretty likely.

If you already have the Fosi - then I'd not go with the class AB amps. When you compare you are likely to be disappointed. If you don't, and then won't be comparing, go with what the heart wants.

 

[SMen]

I have a pair of Irving M Bud Fried SIgnature A 6 transmission line speakers, 2 way, 89 dB sensitivity. I like their sound with my Harman Kardon AVR 3550 - 28 Amperes high current capacity. 65 Watts RMS in 8 Ohms, which is likely 100 Watts out the door.

I'm getting a class AB dual monoblock - 195 Watts * 8 Ohms Stereo amplifier.

How will it compare in sound to Fosi v3 twin monoblocks?
Should I go in for it? will it sound much better? Thank you for your opinions!

There are good, and not so good class AB monoblocks. I'm not sure how it is possible to answer your question objectively!
Someone would need to know the AB dual monoblock you are buying - have used it. I'm not sure that the fact that it is a particular class is the key criteria for how it will perform.

It will be indistinguishable - or so close to indistinguishable as not to matter IF you are playing within the power window of the Fosi - which is a bit less than your proposed monoblocks. With your 89dB sensitivity speakers though, this seems pretty likely.

If you already have the Fosi - then I'd not go with the class AB amps. When you compare you are likely to be disappointed. If you don't, and then won't be comparing, go with what the heart wants.

I'm wondering if this is assuming a particular Harmon model, or I've missed something? Mind you I am just picking up on this thread and reading back ... methinks a bit of a "stirring" might be going on !

 

[antcollinet]

There are good, and not so good class AB monoblocks. I'm not sure how it is possible to answer your question objectively!
Someone would need to know the AB dual monoblock you are buying - have used it. I'm not sure that the fact that it is a particular class is the key criteria for how it will perform.

I'm wondering if this is assuming a particular Harmon model, or I've missed something? Mind you I am just picking up on this thread and reading back ... methinks a bit of a "stirring" might be going on !

The question was about comparison of unnamed AB mono-blocks with FOSI V3 mono. At least that is what I was answering. I was assuming competently designed ABs

 

[SMen]

The question was about comparison of unnamed AB mono-blocks with FOSI V3 mono. At least that is what I was answering. I was assuming competently designed ABs

I'll let you stir that pot! Personally I was drawn to these 3255's because they sounded more powerful and transparent vs my old classAB ... but too sunny here today.

 

[rwnano]

I'll let you stir that pot! Personally I was drawn to these 3255's because they sounded more powerful and transparent vs my old classAB ... but too sunny here today.

What's your old AB like? Please describe in details

 

[rwnano]

These dual monoblocks

Platinum Dual Mono Stereo Power Amplifier India | INDIQAUDIO Bangalore

Buy India’s best Platinum Saptak Dual Mono Stereo Power Amplifier. Our amplifiers are designed for accurate and perfect reproduction of the entire music scale.

www.indiqaudio.com

 

[Killingbeans]

So no actual experience in the audio field - exactly what I thought.

I still don't understand why this has any relevance to the discussion.

Being involved with something at high risk of messing with your head, doesn't make you immune to that risk.

If a geologist says healing crystals is BS, would he/she be checkmate by the person who goes: "So no actual experience in the healing crystal field - exactly what I thought"?

 

[SMen]

What's your old AB like? Please describe in details

oh heavens - it was an old inca-tech claymore!
I used active speakers for a while with ab amps inside - professional wing / spin off from Spendor - but I can't remember the model name. Epos ES14 speakers for a while with Naim ... but the reason I mention is just that I went for higher efficiency speakers (and yours are pretty good ) - and I liked the sound of higher efficient (now Triangle) with the 3255 - just pleasantly surprised - discovered Amirm's review of one of them and progressed from there (Aiyima A70s)

It occurs to me that you will get a flavour (more than) with the stereo Fosi V3s - so for less than 100 $£ euros etc - compare with your ABs

Lots prefer what they call an "AB" sound! But ... I'm not able to properly communicate here right now so just sharing that last thought.

 

[SMen]

These dual monoblocks

Platinum Dual Mono Stereo Power Amplifier India | INDIQAUDIO Bangalore

Buy India’s best Platinum Saptak Dual Mono Stereo Power Amplifier. Our amplifiers are designed for accurate and perfect reproduction of the entire music scale.

www.indiqaudio.com

Heavens! You can try the little fosi v3 stereos against these for the fun of it. You will probably be spending more on cable. THey look great.

 

[rwnano]

Heavens! You can try the little fosi v3 stereos against these for the fun of it. You will probably be spending more on cable. THey look great.

These are available for 800 USD near me in India