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Fosi Audio V3 Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 11 2.5%
  • 2. Not terrible (postman panther)

    Votes: 37 8.4%
  • 3. Fine (happy panther)

    Votes: 215 49.1%
  • 4. Great (golfing panther)

    Votes: 175 40.0%

  • Total voters
    438

OldTimer

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Yes
1) I saw PA5’s SINAD in the blue ‘excellent’ area (in the top 20 of ASR measured amps), so was curious to have an affordable near ‘end game’ amp and call it a day. Especially as many said a V3 without load dependency would be a game changer.
I haven’t experienced +16 SINAD difference before, so have no clue how/if that’d sound. But so far most other upgrades I went with were mostly in the +20% area. I suppose better soundstage, imagining, detail and separation would be some of the most noticeable differences.

2) What bothers me with my Elac DBR62 is that they feel ‘slow’, not as dynamic with the sound. Does sheer Watt-per-channel mitigate that?

To summarise, from what you are saying, the differences in pt 2 have more influence than the differences in pt 1?
Then, doesn’t PA5 II Plus answer both points? Just gonna try to order one when I’m back from holidays.


Might have been Amir in the DBR62 measurements: ‘So you better have a beefy amplifier to drive this speaker.’
Please don’t give up. Every problem will come with a solution. Try to change anything such as flipping left to right both input and speaker cable. Try it one by one. Then change the DAC/Pre-amp and so on. Even rebuild the speaker cable banana plug from the beginning. Just calm down.
 
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K.Kevin

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2) What bothers me with my Elac DBR62 is that they feel ‘slow’, not as dynamic with the sound. Does sheer Watt-per-channel mitigate that?
you may also have to come to terms with the fact that the DBR62 may just be.. slow and lack dynamics. I’m a firm believer in the speaker and the room are the biggest influencers of the sound people hear. Changing amps to “save” or “fix” a speaker is something that fundamentally makes no sense to me. Speakers sound different from one another, there can be wild variations. Whereas amps should theoretically all sound identical, unless they are literally defective at their job of amplifying a signal in a linear way, or unless they don’t have the power to push the speakers to the listeners output requirements (clipping and distortion become serious concerns). If there were any differences between amps, they may only be very small, very minute, very subtle. Why spend so much money on such diminishing returns?

Unless your DBR62 is a really special speaker to you, and is perfect in the other regards, you may want to consider a different speaker? It shouldn’t be off the table.
 

antcollinet

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the DBR62 may just be.. slow and lack dynamics
or it may be that what you perceive as slow and lacking dynamics is due to room interaction and resulting frequency response.

Room treatment and or equalisation may help here.

A new amplifier will not.
 

grogi.giant

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If that is the power a meter gives you, you can be fairly confident the peaks of your music are reaching 10x that or more. (Think crescendos and drum strikes). If you don't want those to clip, this is why you need the power headroom.

That's where the old vinyl released shone. They have loads of dynamic range.

Modern music is compressed beyond imagination, there are hardly any peaks anymore. :(
 

K.Kevin

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or it may be that what you perceive as slow and lacking dynamics is due to room interaction and resulting frequency response.

Room treatment and or equalisation may help here.

A new amplifier will not.
It’s true, but for most people serious room treatment is off the table, maybe a rug aside. Their room is as is, structurally, and aesthetically. In that case the only high-value-for-money fix is different speakers that hopefully interact and sum up with the room differently. You would need one with a solid return policy to trial them and determine what works best.

EQ is a high value improvement in general, but that user specifically talked about how his speakers don’t sound dynamic and seem slow. I don’t think EQ can easily solve that. The Elac is practically on the opposite end of the spectrum to a high sensitivity high dynamics home theater speaker. If that user wants to improve those symptoms, I think getting a speaker that is closer on that opposite side of the spectrum, with higher sensitivity and a design that prioritizes dynamics would provide a more noticeable change in auditory experience compared to a new amp. It doesn’t need to be a brutish “home theater” speaker, but just something further away from the DBR62 and Elac’s design philosophies.
 

antcollinet

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It’s true, but for most people serious room treatment is off the table, maybe a rug aside. Their room is as is, structurally, and aesthetically. In that case the only high-value-for-money fix is different speakers that hopefully interact and sum up with the room differently. You would need one with a solid return policy to trial them and determine what works best.

EQ is a high value improvement in general, but that user specifically talked about how his speakers don’t sound dynamic and seem slow. I don’t think EQ can easily solve that. The Elac is practically on the opposite end of the spectrum to a high sensitivity high dynamics home theater speaker. If that user wants to improve those symptoms, I think getting a speaker that is closer on that opposite side of the spectrum, with higher sensitivity and a design that prioritizes dynamics would provide a more noticeable change in auditory experience compared to a new amp. It doesn’t need to be a brutish “home theater” speaker, but just something further away from the DBR62 and Elac’s design philosophies.
Sensitivity has nothing to do with dynamics. It is simply how much SPL you get for your power into the speaker.

that perception of slow - what does it mean? It certainly doesnt mean the drivers are slow to respond to the signal - that is not how speakers work. If they can do 20Khz that is as fast as they need to move.

The perception normally comes from an in room frequency/phase response issue. This is where equalisation can help.
 

BogdanR

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Late to the party here but with a simple question: would this amp work in a power amp configuration? I mean like hooked up to my small NAD pre?
I haven’t seen anywhere actual I/O specs on this. Actually input specs would be good I think.
It matters very little to me whether I control the actual volume from the pre or from the amp, as I’m only looking for some input switching convenience. I’d rather not fry the input of the V3 which would be rather simple if I knew what its specs were.
 

antcollinet

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Late to the party here but with a simple question: would this amp work in a power amp configuration? I mean like hooked up to my small NAD pre?
I haven’t seen anywhere actual I/O specs on this. Actually input specs would be good I think.
It matters very little to me whether I control the actual volume from the pre or from the amp, as I’m only looking for some input switching convenience. I’d rather not fry the input of the V3 which would be rather simple if I knew what its specs were.
From the dashboard we can see the gain is 26.4dB

Peak power with 48 V supply is around 120W at 8ohm = 31V output.

So 1.4V on input will drive it to full power. I'd expect that the inputs can cope with significantly more than that. You'll be absolutely safe if you limit your preamp output to 2V
 

CauliflowerEars

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@Gygess @antcollinet @olieb
As always, thank you very much for the very insightful discussion. If I’m not mistaken, would a following summary be correct?

1) Don’t bother with a better amp, V3 is already a very good ‘middle ground’.
Which other amp and price range would be a good upgrade from the V3?
The reasons I was considering PA5 is that I like to have as much quality in a given price range as possible. Don’t want any ‘bottlenecks’. PA5 seems to be giving better SINAD and no load dependency.

2) Should I rather consider finally getting the UMIK mic + audio interface and work with room measurements?

3) Some others have also suggested adding a subwoofer. (as Gygess said: maybe test other speakers as well).

-
The way I’d picture ‘slow’ speakers is:
Imagine the speakers/drivers being an orchestra. Music source being a conductor.
With ‘slow’ speakers it would feel as if either the musicians have slow movements or the air between them and the conductor was thick and they can’t spot his movements fast enough or the music moves slower through the air.
‘Fast’ speakers would appear as if the musicians are very fast, energetic and responsive, the air very clean.

How that translates to engineering and how actually speakers work, I unfortunately don’t know. Maybe it’s just more bass than treble.

Maybe it’s placebo, as I’ve seen descriptions of DBR62 being laid back, mellow, etc. is there some counter placebo I could serve myself? But then, other speakers in my bedroom do sound fast.
 

antcollinet

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@Gygess @antcollinet @olieb
As always, thank you very much for the very insightful discussion. If I’m not mistaken, would a following summary be correct?

1) Don’t bother with a better amp, V3 is already a very good ‘middle ground’.
Which other amp and price range would be a good upgrade from the V3?
The reasons I was considering PA5 is that I like to have as much quality in a given price range as possible. Don’t want any ‘bottlenecks’. PA5 seems to be giving better SINAD and no load dependency.
The better sinad of the PA5 is almost certainly inaudible in real world listening conditions. There'll certainly be no "night and day" difference. If you want to test your own ability to detect distortion and what level you can hear try the klippel test:
listeningtest

2) Should I rather consider finally getting the UMIK mic + audio interface and work with room measurements?
Definitely - and you don't need an interface. The Umik has a usb interface already. Connect direct to computer.


3) Some others have also suggested adding a subwoofer. (as Gygess said: maybe test other speakers as well).
Can help - but do measurements first and find a way to implement room correction.

Maybe it’s placebo, as I’ve seen descriptions of DBR62 being laid back, mellow, etc. is there some counter placebo I could serve myself? But then, other speakers in my bedroom do sound fast.
Based on your description I think it may well be placebo. I'm not aware of any speaker characteristic that could cause that. But in any case, get the measurements and correction in place then see if they still sound "slow".
 

K.Kevin

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@Gygess @antcollinet @olieb
As always, thank you very much for the very insightful discussion. If I’m not mistaken, would a following summary be correct?

1) Don’t bother with a better amp, V3 is already a very good ‘middle ground’.
Which other amp and price range would be a good upgrade from the V3?
The reasons I was considering PA5 is that I like to have as much quality in a given price range as possible. Don’t want any ‘bottlenecks’. PA5 seems to be giving better SINAD and no load dependency.

2) Should I rather consider finally getting the UMIK mic + audio interface and work with room measurements?

3) Some others have also suggested adding a subwoofer. (as Gygess said: maybe test other speakers as well).

-
The way I’d picture ‘slow’ speakers is:
Imagine the speakers/drivers being an orchestra. Music source being a conductor.
With ‘slow’ speakers it would feel as if either the musicians have slow movements or the air between them and the conductor was thick and they can’t spot his movements fast enough or the music moves slower through the air.
‘Fast’ speakers would appear as if the musicians are very fast, energetic and responsive, the air very clean.

How that translates to engineering and how actually speakers work, I unfortunately don’t know. Maybe it’s just more bass than treble.

Maybe it’s placebo, as I’ve seen descriptions of DBR62 being laid back, mellow, etc. is there some counter placebo I could serve myself? But then, other speakers in my bedroom do sound fast.
I’m not saying a better amp can’t help, and I’m not saying the PA5 wouldn’t be better, but I do think the difference would be minimal, and poor value for money given that I don’t believe your speakers are that hard to drive relative to many other speakers. If you mentally cannot handle not having the best, I have no problem with those who are self-aware of that and don’t push or propagate false self-soothing narratives to others that their life changed from such minute changes. It’s only one step removed from snake oil: this is a category of items that has verifiable measurable technical benefit but will inevitably be unlikely to notice perceptual benefits. If someone peddled fancy $1000 speaker wire that technically had measurable electrical benefits in its construction, nobody here would condone it and would call it out as snake oil. Where does one draw the line with things like Sinad? Sure, it’s not as big a rip off as $1000 speaker wire, but where is the same type of critical thinking as to whether one will actually hear audible differences between 5db Sinad discrepancies in a double-blind state? Why does ASR accept the latter, but probably ridicule the former?


If you have the time and commitment to turn to room correction, including treatment where needed, sure, I think that would create a bigger influence and value for money on the sound you will hear at your ears.


I disagree with others here if they say a speaker (relative to another speaker) can’t sound slow or warm or laid back or whatever else. I think crossover components and design, and driver properties, such as the materials used, how light or stiff they are, these things that speaker manufacturers have constantly been researching and improving over the decades, I think they do influence how a speaker behaves. I’ve heard elac speakers, and I myself had the same impression of laid back sound.


I’m not saying a high sensitivity to the speaker causes these differences. I’m saying that a high sensitivity speaker (this is relative too, I mean bookshelf to bookshelf and tower to tower) usually indicates the designer/components have prioritized factors such as dynamics. You’ve never heard anyone describe an IMAX theater sound as “laid back”.


It’s possible with EQ that the response curves can be edited to sound like the IMAX speaker… but it’s also possible you cannot and it will never achieve that. EQ can change the decibel output at a certain frequency- it cannot change the spatial features of a speaker, such as its dispersion, dispersion patterns, the location of ports and how it interacts with the room, etc. this is why different speakers may still be the high-value-for-money alteration to the eventual sound your ears hear, despite all the things you can do with your room and EQ.
 
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mike70

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The focus on SINAD measurements are primarily to test the amplifier engineering. After certain threshold, less noise and distortion is totally silly in the real world (domestic audio).

Speakers distortion, room interaction, noise floor, wasted ears, ... my friend, with 85dB SINAD you're more than good.

Theory is only equals to practice in theory.
 

king0188

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Where is the amplifier chip? On the backside?
index.php
 

Bruce Morgen

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Where are those big (2200uF!) electrolytic capacitors connected in the circuit? Are they simply in shunt across the DC input for lots of "reservoir" or "smoothing" effect when the amp is running normally -- and is that why there's a relay involved, to implement some sort of "soft start" capability when the amp is first turned on?
 

antcollinet

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Where are those big (2200uF!) electrolytic capacitors connected in the circuit? Are they simply in shunt across the DC input for lots of "reservoir" or "smoothing" effect when the amp is running normally -- and is that why there's a relay involved, to implement some sort of "soft start" capability when the amp is first turned on?
Yes, and yes.

See the NTC top right. That will be a high resistor at low temperatures which the capacitors get charged through. The relay will short it out.

As the temperature of the NTC goes up, it's resistance reduces - a characteristic they might use to limit the current as the capacitors voltage is low, but allow the full voltage to be reached faster as the caps charge up - or they might not care about that, and just be using it as a robust resistor capable of withstanding high current pulses.
 

Quexos

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I got my V3 a couple weeks ago and just added a $36 SybaSonic DAC/HP amp/pre-amp (SD-DAC63118) and the combo sounds really good. After adding the Syba DAC, I had to drop the volume on the Fosi quite a bit, it got much louder. I've never owned super high end stuff to compare it to, but it sure sounds better than some of the other stuff I've seen, as good as my full blown Sony/Yamaha receivers did, without taking up so much space on my desk and acting like a friggin space heater in the middle of summer. I think the V3 does sound a bit better with the Syba as a pre-amp on it.

I'm just using it for PC audio. USB to SybaSonic DAC, then RCA out to Fosi Audio V3, and on to SUB and Speakers. Sounds pretty darned good.
 

OldTimer

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I got my V3 a couple weeks ago and just added a $36 SybaSonic DAC/HP amp/pre-amp (SD-DAC63118) and the combo sounds really good. After adding the Syba DAC, I had to drop the volume on the Fosi quite a bit, it got much louder. I've never owned super high end stuff to compare it to, but it sure sounds better than some of the other stuff I've seen, as good as my full blown Sony/Yamaha receivers did, without taking up so much space on my desk and acting like a friggin space heater in the middle of summer. I think the V3 does sound a bit better with the Syba as a pre-amp on it.

I'm just using it for PC audio. USB to SybaSonic DAC, then RCA out to Fosi Audio V3, and on to SUB and Speakers. Sounds pretty darned good.
I wonder why the V3 need a good DAC/pre-amp to shine.
 
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