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Fosi Audio V3 Mono Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 13 2.0%
  • 2. Not terrible (postman panther)

    Votes: 21 3.2%
  • 3. Fine (happy panther)

    Votes: 128 19.3%
  • 4. Great (golfing panther)

    Votes: 501 75.6%

  • Total voters
    663
Hello! My current system is - fosi zd3 + aiyima a70. The sound is fine, but I got the idea of replacing the aiyima a70 with two fosi v3 mono. Please tell me if it's worth doing or not? Maybe there is someone who owned them and compared them? Thanks)
 
Hello! My current system is - fosi zd3 + aiyima a70. The sound is fine, but I got the idea of replacing the aiyima a70 with two fosi v3 mono. Please tell me if it's worth doing or not? Maybe there is someone who owned them and compared them? Thanks)
The onlly thing the V3 will bring you is a little more power.

But it is only 1.3dB more power resulting in an approx 13% increase in perceived volume.

Personally I would not bother.
 
The onlly thing the V3 will bring you is a little more power.

But it is only 1.3dB more power resulting in an approx 13% increase in perceived volume.

Personally I would not bother.
13% - is it an increase of the perceived volume or rather the ratio of powers? The perceived increase of volume will be next to none.
 
13% - is it an increase of the perceived volume or rather the ratio of powers? The perceived increase of volume will be next to none.
Percieved volume. Which is why I said "perceived volume" :p . And yes, a 13% perceived volume change not very noticeable - certainly not worth paying a few hundred £$ for. But it is noticeable.


1.3dB as a percentage of power is about 35%
 
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Percieved volume. Which is why I said "perceived volume" :p . And yes, a 13% perceived volume change not very noticeable - certainly not worth paying a few hundred £$ for. But it is noticeable.


1.3dB as a percentage of power is about 35%
Right, right... 10 lg (power_ratio) = 1.3dB ==> power_ratio = 10 ** 0.13 = 1.35 ==> power_increase_percent = 35%

I guess, my question is how you arrived at the perceived volume (loudness?) increase.
 
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Hello! My current system is - fosi zd3 + aiyima a70. The sound is fine, but I got the idea of replacing the aiyima a70 with two fosi v3 mono. Please tell me if it's worth doing or not? Maybe there is someone who owned them and compared them? Thanks)
I think the A70 is a step up from the previous A08 I had, and I moved to two V3 monos, but for me the pivot point is the relay volume control I now use with the Monos.

Where it comes to volume, I find having a small (they are not expensive) dB meter really useful, because, depending on the size of your room, speakers, efficiency etc. you may find that actually 85 db is very loud ... and having an amplifier that lets you play at 95dB instead of say 93 db (which you would not want to anyway) is superfluous.

So the monos bring other factors into play other than power, like slotting nicely under my tv for example (which the other shapes and sizes don't)!
 
Right, right... 10 lg (power_ratio) = 1.3dB ==> power_ratio = 10 ** 0.13 = 1.35 ==> power_ratio_increase_percent = 35%

I guess, my question is how you arrived at the perceived volume (loudness?) increase.
Yes + 1 for an interesting question for @antcollinet
 
Yes + 1 for an interesting question for @antcollinet
It is fairly well established that +10dB results in an approximate doubling of perceived volume (+100 %)

Since our perception of volume is similarly logarithmic, I tend to use the % of 10dB as the % of volume increase. In this case. 1.3dB is 13%. This is not strictly accurate - you can't have 10x 10%. increases from the previous level and then reach a total of 100% - but since the perception won't be precise (the auditory system consisting of a combination of meat-ware and wet-ware) and will similarly vary a little from person to person, I view it as "close enough for government work"


EDIT - having looked at it a bit more, each dB of power results in a multiple of perceived volume of near as damnit x1.072 (Assuming we accept 10dB = x2)

So for any dB figure, perceived volume multiplier is 1.072^(dB power change)

So 1.3dB is around 9% increase in perceived volume. (subject to meatware/wetware variation yada yada)
 
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Has anyone figured out a way to eliminate the pop when the amp powers on from Auto mode? It's a huge thump through my speakers. I am running the Wiim Ultra through the Fosi ZD3 through the V3's. I am using the XLRs from the DAC to the amps. Could this damage my speakers?
 
Has anyone figured out a way to eliminate the pop when the amp powers on from Auto mode? It's a huge thump through my speakers. I am running the Wiim Ultra through the Fosi ZD3 through the V3's. I am using the XLRs from the DAC to the amps. Could this damage my speakers?

I wonder why your system does this? My system uses the Wiim Ultra through a pair of V3 monos set to auto and they start up without a thump. I hear a faint click from the V3 relay
 
Has anyone figured out a way to eliminate the pop when the amp powers on from Auto mode? It's a huge thump through my speakers. I am running the Wiim Ultra through the Fosi ZD3 through the V3's. I am using the XLRs from the DAC to the amps. Could this damage my speakers?
I wonder why your system does this? My system uses the Wiim Ultra through a pair of V3 monos set to auto and they start up without a thump. I hear a faint click from the V3 relay

Perhaps the ZD3 is outputting some DC which is amplified and dropped onto the speakers at power on?
 
I wonder why your system does this? My system uses the Wiim Ultra through a pair of V3 monos set to auto and they start up without a thump. I hear a faint click from the V3 relay
My v3 monos used to do this when run from a single 10A supply with dc filter. I suspect that if the two amps come out of standby at slightly different times you get this. I changed to 2 supplies (aiyama gain) and no longer does it.
 
My v3 monos used to do this when run from a single 10A supply with dc filter. I suspect that if the two amps come out of standby at slightly different times you get this.
I don’t think that’s it. I’m running both of mine through the single 10A supply and filter and have never gotten a pop or any other audible noise from the speakers when they switch on — and I do hear the relay clicks slightly out of sync.
 
Perhaps the ZD3 is outputting some DC which is amplified and dropped onto the speakers at power on?
It's the ZD3 with a slight lag when it's turned on via the 12v trigger. I removed the DAC from the equation and connected without the DAC using RCAs. No pop sound. Is there a solution that would allow me to keep the DAC and still keep the V3's in auto mode? I wonder if the same would occur if I had ZA3's in mono using the 12 v trigger from the DAC? Or should I just consider ditching the class D amps for a class AB amp?
 
It's the ZD3 with a slight lag when it's turned on via the 12v trigger. I removed the DAC from the equation and connected without the DAC using RCAs. No pop sound. Is there a solution that would allow me to keep the DAC and still keep the V3's in auto mode? I wonder if the same would occur if I had ZA3's in mono using the 12 v trigger from the DAC? Or should I just consider ditching the class D amps for a class AB amp?
Ditch the dac. It wont give you anything compared to the one in the ultra.
 
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