Fosi Audio V3 Mono Amplifier Review

[OldTimer]

Careful you will get a lot of criticism, this thing is modern, unreliable and dangerous for your electrical system
Again, any DAC, and by 'modern' I meant that can output >1 A via RCA (or >2V via XLR/TRS) and has some sort of volume control will do.
So your receiver is fine indeed, just get as many monoblocks as channels you want amplified.

I have the original V3, bought last year. Still haven’t found any problem. Nicely sing the song loud and clear.

 

[Yorkshire Mouth]

Different sources will have different starting gain levels, so the amount of gain at the power amp should vary as well to balance things out. My multimode preamp, for example, has a passive mode and a unity gain solid state buffer mode, but the tube buffer mode has a big gain, it’s nice to have only 20db gain on the balanced input of the V3 Mono since I do my critical listening in tube buffer mode. Granted, when using solid state buffer mode, I will simply turn the volume up on my preamp to compensate for background/casual listening, but in those situations, I don’t tend to raise the volume as high as I do in critical listening anyway.

-Ed

Thanks for taking the time and trouble to answer.

I’m still list, though. Surely the very specific +21 and +35 are for two very specific instances.

 

[sikahr]

For the reference Fosi V3 Mono Rated power @ 48V PSU

 

[SMen]

Same here, and I think we'll get it, it's been what 24 hours since the Kick Starter campaign opened and it's already funded to $210K out of the $300K

I just hope they include a pair of opamps per mono block.

Do you get all the tool kit, cables and opamps if it hits $300K?

I'm not sure what the benefit is of just one op amp.
Except on the single to balanced conversion.
This is presuming one per amp, and not one per order.
Anyone wanting to try these on the balanced inputs would need therefore to buy another 2 or 3!
Some confusion here @Fosi Audio

 

[amix]

(2nd part)

Better put that into a spoiler ;-)

 

[jvdburgt]

You will need 9 units of the V3 mono to amplify all pre-out channels of the receiver.

Just the fronts and the center speaker

Surrounds are fine with the internal amp

 

[Adrian Parker]

More on OpAmps, live review of ZA3 by @VirtualHiFi

Sound difference between stock opamps and Sparkos night and day, in my opinion, and that of many others too.

Fosi ZA3 + Sparkos Op-amp - The real deal - Don't miss out !!! Interested in Sparkos Opamps - visit www.sparkoslabs.com

"Fosi is a great little amp that can put many multiple thousand $$$ to real shame. The TPA3255 which is a heart of this amplifier is my favorite D-class Amp chip. It's dynamic, fast and tight, but also has the most wonderful midrange that I like even more than most class AB amps. So how about upgrading it with one of the finest Op-amps - Sparkos Labs SS3602. This is a fully discrete op-amp and the combo is amazing. What's better than me saying it ? You being able to hear it yourself."

In this video is a demo of the Fosi ZA3 with standard opamps and with Sparkos Labs SS3602.
Over 20 minutes of sound demo for you across different genres so that you can enjoy and make up your mind
0:00 - The Sparkos & The Fosi
2:41 - How to replace the Op-amps
10:27 - One more trick - even less Op-amps needed
14:15 - All that you are - Elvin Vanguard
15:45 - Purple Beach - Giants’ nest
17:15 - Monsoons - Johannes Bornlof
18:45 - The Last Kiss - Ritchie Everett
20:15 - Love You For It All - Daniel Gunnarsson
21:45 - Wood & Skin - Hara Node
23:15 - Something new - Anthony Lazaro feat Sarah Kang (Korean Version)
24:45 - Folium - Bladverk Band
26:15 - Air on the G String - Johannes Bornlof
27:45 - Coming Home Blues - Bo the Drifter
29:15 - Intimacy - Alex Kehm
30:45 - I Am Better Off (Jazz version) - Wildson
32:15 - Wandering Nomad - Cody Francis
33:45 - Virga - Bladverk Band
35:15 - The One - Ritchie Everett
36:45 - Conclusions

​

 

[somebodyelse]

Sound difference between stock opamps and Sparkos night and day, in my opinion, and that of many others too.

In sighted tests without level matching no doubt. Now try level matched and without peeking.

 

[olieb]

Sound difference between stock opamps and Sparkos night and day

Oh the old "night an day" story again.
In fact it is Sparkos trying to cash in on the V3mono hype by pulling the fomo trigger.

 

[Sokel]

More on OpAmps, live review of ZA3 by @VirtualHiFi

Sound difference between stock opamps and Sparkos night and day, in my opinion, and that of many others too.

Fosi ZA3 + Sparkos Op-amp - The real deal - Don't miss out !!! Interested in Sparkos Opamps - visit www.sparkoslabs.com

"Fosi is a great little amp that can put many multiple thousand $$$ to real shame. The TPA3255 which is a heart of this amplifier is my favorite D-class Amp chip. It's dynamic, fast and tight, but also has the most wonderful midrange that I like even more than most class AB amps. So how about upgrading it with one of the finest Op-amps - Sparkos Labs SS3602. This is a fully discrete op-amp and the combo is amazing. What's better than me saying it ? You being able to hear it yourself."

In this video is a demo of the Fosi ZA3 with standard opamps and with Sparkos Labs SS3602.
Over 20 minutes of sound demo for you across different genres so that you can enjoy and make up your mind
0:00 - The Sparkos & The Fosi
2:41 - How to replace the Op-amps
10:27 - One more trick - even less Op-amps needed
14:15 - All that you are - Elvin Vanguard
15:45 - Purple Beach - Giants’ nest
17:15 - Monsoons - Johannes Bornlof
18:45 - The Last Kiss - Ritchie Everett
20:15 - Love You For It All - Daniel Gunnarsson
21:45 - Wood & Skin - Hara Node
23:15 - Something new - Anthony Lazaro feat Sarah Kang (Korean Version)
24:45 - Folium - Bladverk Band
26:15 - Air on the G String - Johannes Bornlof
27:45 - Coming Home Blues - Bo the Drifter
29:15 - Intimacy - Alex Kehm
30:45 - I Am Better Off (Jazz version) - Wildson
32:15 - Wandering Nomad - Cody Francis
33:45 - Virga - Bladverk Band
35:15 - The One - Ritchie Everett
36:45 - Conclusions

​

​

No measurements whatsoever.
Are we seriously still talking about this channel?
After all they have stated all this time?

 

[SMen]

In sighted tests without level matching no doubt. Now try level matched and without peeking.

Yes, there is no doubt that we tend to prefer higher gain when doing a comparison.

 

[Sokel]

In sighted tests without level matching no doubt. Now try level matched and without peeking.

Or they can just record the two versions directly at the output of the amp,electrically (whole song) and upload them.
Deltawave will tells us the story from then on.

 

[amix]

I have a WiiM too, but just in case the device resets itself or something else bad happens, you suddenly blow your speakers up with so much watts.

Right.

A proper setup always has a preamplifier. Everything else is a hack to save money.

 

[Dr. Noooooo]

Better put that into a spoiler ;-)

Well it’s easy to just listen the track and check your findings later. However, sloppy job with the channels does kind of ruin that part of the test and make it harder to tell whether there’s actual discrepancies in the sound itself (unless you are willing to listen them in mono). Also such short samples played in continuous sequence doesn’t make it easy for comparison purposes either (e.g. there’s different passages such as dynamics and/or instrumentation, vocals vs. no vocals etc. in the song and the switches fall in between them).

 

[early rejecter]

I'm not sure what the benefit is of just one op amp.

All explained in post #907 here. Only one needed per amp to start experimenting if that’s something you want to do.

 

[DavidM1]

More on OpAmps, live review of ZA3 by @VirtualHiFi

Sound difference between stock opamps and Sparkos night and day, in my opinion, and that of many others too.

Fosi ZA3 + Sparkos Op-amp - The real deal - Don't miss out !!! Interested in Sparkos Opamps - visit www.sparkoslabs.com

"Fosi is a great little amp that can put many multiple thousand $$$ to real shame. The TPA3255 which is a heart of this amplifier is my favorite D-class Amp chip. It's dynamic, fast and tight, but also has the most wonderful midrange that I like even more than most class AB amps. So how about upgrading it with one of the finest Op-amps - Sparkos Labs SS3602. This is a fully discrete op-amp and the combo is amazing. What's better than me saying it ? You being able to hear it yourself."

In this video is a demo of the Fosi ZA3 with standard opamps and with Sparkos Labs SS3602.
Over 20 minutes of sound demo for you across different genres so that you can enjoy and make up your mind
0:00 - The Sparkos & The Fosi
2:41 - How to replace the Op-amps
10:27 - One more trick - even less Op-amps needed
14:15 - All that you are - Elvin Vanguard
15:45 - Purple Beach - Giants’ nest
17:15 - Monsoons - Johannes Bornlof
18:45 - The Last Kiss - Ritchie Everett
20:15 - Love You For It All - Daniel Gunnarsson
21:45 - Wood & Skin - Hara Node
23:15 - Something new - Anthony Lazaro feat Sarah Kang (Korean Version)
24:45 - Folium - Bladverk Band
26:15 - Air on the G String - Johannes Bornlof
27:45 - Coming Home Blues - Bo the Drifter
29:15 - Intimacy - Alex Kehm
30:45 - I Am Better Off (Jazz version) - Wildson
32:15 - Wandering Nomad - Cody Francis
33:45 - Virga - Bladverk Band
35:15 - The One - Ritchie Everett
36:45 - Conclusions

​

​

I think a very easy blind test is to simply close your eyes and see if you can identify when the op amp has changed. Another would be to cover the screen and run your finger randomly along the time bar. If you can consistently pick the correct amp from its sound alone then you definitely have a case.

 

[somebodyelse]

Yes, there is no doubt that we tend to prefer higher gain when doing a comparison.

See also the section on the 'Wason effect' (best tried on headphones):

Spoiler: Explanation if you don't want to watch the video

There is no 'Wason effect' - it's a demonstration of confirmation bias prompting people to 'hear' a difference where there isn't one. This is why we need to test with all cues removed, visual or otherwise.

 

[SMen]

All explained in post #907 here. Only one needed per amp to start experimenting if that’s something you want to do.

Yes I know, but personally I do not understand this with a parallel circuit.

 

[SMen]

See also the section on the 'Wason effect' (best tried on headphones):

Spoiler: Explanation if you don't want to watch the video

There is no 'Wason effect' - it's a demonstration of confirmation bias prompting people to 'hear' a difference where there isn't one. This is why we need to test with all cues removed, visual or otherwise.

That's very good thank you. Also the bit about the masking, and our ability to 'fill in'. I've often thought this ... but funnily enough it also makes me think that 'quick switching' between two options has its weaknesses too. Our brains are trying their best to interpret the sounds we hear and the thought process "changing op amps is a load of rubbish" is in itself an influencer.

This is probably why this is such a thorny issue (e.g. op amps) between different points of view. But heck ... I listen to records !!

 

[somebodyelse]

That's very good thank you. Also the bit about the masking, and our ability to 'fill in'. I've often thought this ... but funnily enough it also makes me think that 'quick switching' between two options has its weaknesses too. Our brains are trying their best to interpret the sounds we hear and the thought process "changing op amps is a load of rubbish" is in itself an influencer.

Not hearing something you should be able to is another demonstrated form of confirmation bias, and should be accounted for in good test design. You'll see this in the good published studies. It's not so easy with self-administered tests though. I think quick switching being more sensitive (among other things) is covered in https://www.audiosciencereview.com/...d-testing-you-are-doing-it-wrong-video.26809/ - there's nothing stopping you doing slow blind tests but the evidence is they're less likely to show differences. Anything further is going to take us well off topic into that thread or https://www.audiosciencereview.com/...are-measurements-everything-or-nothing.29062/

This is probably why this is such a thorny issue (e.g. op amps) between different points of view. But heck ... I listen to records !!

So do I! At least with records it's easy to show that small adjustments make a measurable difference, often plenty big enough to hear