Fosi Audio V3 Mono Amplifier Review

[Freezak]

I also get the pop out of the speakers when they power up. How are you connected to them XLR or RCA? I get of a pop with RCA.

In my case there's an amp pop with XLR and a faint one in the speakers too when turning off the mains. I use two Monos with SMSL D6s + ELAC DBR62.

Is the speaker faint pop actually harmful for them and should i refrain from disconnecting the power strip? the sound is not loud at all.

I do this using a remote so it's much more convenient than physically turning the monos off but if it harms the speakers in any way then i guess i have to stop doing this.

 

[antcollinet]

In my case there's an amp pop with XLR and a faint one in the speakers too when turning off the mains. I use two Monos with SMSL D6s + ELAC DBR62.

Is the speaker faint pop actually harmful for them and should i refrain from disconnecting the power strip? the sound is not loud at all.

I do this using a remote so it's much more convenient than physically turning the monos off but if it harms the speakers in any way then i guess i have to stop doing this.

You will get a pop on switch on from the amp if your source is putting out any DC. It might have nothing to do with the amp. Try switching on/off without any input connected to check.

 

[MT_bassbone]

I also get the pop out of the speakers when they power up. How are you connected to them XLR or RCA? I get of a pop with RCA.

Sorry this should have said I get a pop with XLR but drastically less with RCA.

 

[Antlestxp]

Sorry this should have said I get a pop with XLR but drastically less with RCA.

RCA

 

[Nopiano]

The Cambridge CXA61 and CXA81 were a no go. Too warm for my taste.

Interesting that you found them tonally different from the Fosi pair. Just not to your taste? I wonder what measurements would have revealed that?

 

[drodgers]

FWIW I have a CXA81 which I replaced with V3s and haven’t noticed any tonal difference (though I haven’t done a full blinded test)

 

[SMen]

FWIW I have a CXA81 which I replaced with V3s and haven’t noticed any tonal difference (though I haven’t done a full blinded test)

Not noticing is the FWIW (and interesting) bit, and a good reason not to bother with a blind test.

 

[mike70]

we can use a simplified model ...
what is sound? frequencies translated in the air
what is a tonal difference? a difference in that frequencies
if the amplifier have a flat frequency response, there will be no tonal difference with other flat frequency response amplifier

so, if you can hear a tonal difference, is everything else (acoustics, speakers, gain, ..., mental bias) than a real amplifier difference.

i think is very simple ... and we know based on measureaments that the Fosi and the Cambridge have a flat frequency response.

 

[MT_bassbone]

Interesting that you found them tonally different from the Fosi pair. Just not to your taste? I wonder what measurements would have revealed that?

In my opinion the CXA61/81's warmth sacrificed clarity. So the far the Fosi V3 mono's are working the best for me. I am going to audition the Topping B100 monoblocks in a few days.

 

[mike70]

 

[Rotel75]

I've been using the V3M XLR input (RCA to XLR cable) because my preamp (RCA out) has too much gain.
For me this solution sounds great and the question is:
- why does this work, feading the XLR with half the signal
- if it works, why is there an additional/3rd opamp (se to balanced)
- what could go/sound wrong (lower XLR input impedance)

 

[petch]

No pop for me, but an individual V3 mono is significantly hotter than a ZA3 in stereo. Both with XLR and 48V/5A power supply from Fosi

V3 mono also a bit quieter than the ZA3 in identical setup (other than ZA3 being used in stereo)

Edit: just measured with my infrared thermometer, the top is at 53c when completely idle. The ZA3 at least had to be doing something to get a little warm. Concerning?

 

[MT_bassbone]

I have been listening to the V3 monos and ZD3 for a few weeks now. I think I am ready to move on. They are great for the price, but I like the Topping B100 monos (and the E70 Velvet) better.

 

[DavidMcRoy]

I have been listening to the V3 monos and ZD3 for a few weeks now. I think I am ready to move on. They are great for the price, but I like the Topping B100 monos (and the E70 Velvet) better.

I'm using V3 Monos to drive a pair of ESS Heil AMT "Large" tweeters above 2000Hz, and contemplating Topping B100s instead. Looking forward to comparisons. I know ti measures quieter and cleaner, but audibly so? (I'm guessing not.)

 

[Old_School_Brad]

No pop for me, but an individual V3 mono is significantly hotter than a ZA3 in stereo. Both with XLR and 48V/5A power supply from Fosi

V3 mono also a bit quieter than the ZA3 in identical setup (other than ZA3 being used in stereo)

Edit: just measured with my infrared thermometer, the top is at 53c when completely idle. The ZA3 at least had to be doing something to get a little warm. Concerning?

All other factors remaining constant, higher temperatures lead to a reduced lifespan for electronic components, particularly capacitors.

A temperature of 53 °C feels noticeably hot.

For metal surfaces on household appliances, 55 °C is the maximum permissible temperature for short-term skin contact (1–3 seconds).

 

[drodgers]

With the price of the Fosis though, I’m not sure that reliability matters as much. If one blows, you’re not having to ship a heavy amp for repairs and be without for weeks/months. You could literally get a same day replacement from Amazon for the price of shipping a bigger amp, then look into warranty options for the dead one.

Given that amps are generally the least reliable component (thanks to high currents and other stresses), I think easy replacement is a big advantage.

 

[Old_School_Brad]

With the price of the Fosis though, I’m not sure that reliability matters as much. If one blows, you’re not having to ship a heavy amp for repairs and be without for weeks/months. You could literally get a same day replacement from Amazon for the price of shipping a bigger amp, then look into warranty options for the dead one.

I understand, but I don't agree with the mindset.
Futile, I know.

 

[drodgers]

I get it. I also like to buy-for-life where possible. That doesn’t really seem like an option with amps though? At minimum you’ll need a recap every 5-10 years, and you’d be lucky to get that done professionally for less than the price of replacement V3s.

When the measurements are great, and the costs are so low, it’s hard to justify the old approach (I say having recently switched out some old beloved amps for Fosi V3s).

 

[mike70]

I have been listening to the V3 monos and ZD3 for a few weeks now. I think I am ready to move on. They are great for the price, but I like the Topping B100 monos (and the E70 Velvet) better.

If you try a blind test, maybe you can find other result.
I mean, you have all the right to think the B100's better and it's ok (is what you "perceive") ... but ... it's a totally subjective opinion and maybe opposite to the truth.
That's all.

 

[johnp98]

I am wondering if this amp (or looking for other suggestions) would be a good addition to my setup.

I currently use a Denon AVR but it can only power 9 channels and so it is running 7.2.2 but I am looking for a separate amp to get to the 7.2.4 setup that I want.

I initially was thinking of getting a cheap amp for my atmos speakers but now I am thinking why not buy an amp for the L+R channels (and use the AVR pre-outs) as that would free up a lot of the power on the AVR and probably sound better for the main speakers as well.

Anyway, I have been looking for cheap amps that would be an improvement over the Denon AVR and thought this might fit the bill.

I listen to music and home theater content 50:50
My speakers are DIYSG HTM 12v2 (sensitivity 91
I listen at 2m distance.

I have been looking into the 3e Audio A5/7 and the Fosi V3 Mono but wondering if people think those would work for me and if they thought one would be better than the other or if there are other amplifiers that I should consider.

Thanks for any suggestions!