Fosi Audio V3 Mono Amplifier Review

[SMen]

First we have to define "different". Is it "performing better" or "sounding better to my taste"? And in the former case, what's your taste?

If you randomly swap in op-amps with different operating parameters, you'd might hit a combo that gives an instability with tons of distortion. Maybe that will be pleasing to you. Most likely it won't be bad enough to actually be audible. You'd also be highly at risk of getting a placebo effect going.

Either way, doing these kind of swaps, without verification through measurements and sensible judgement of the results, is a frivolous exercise, IMO.

We replied at the same time... My findings with these is that there is distortion ... but I can't measure it, just hear it on things like violins. But I'll expand when I have a moment over on the user impressions.

 

[SMen]

But nontheless ist is still favored by the manufacturer, because he might sell you some (expensive ?) additional OP amps (to the ones already installed in the power amp) he makes additional money on them

Yes - it is seriously getting out of hand IMO. At this rate I'll have written my post!
We need measurements from the manufacturers to justify these diversions.

Post edit: I posted this request from 3e audio on their PFFB thread and received a very positive response.
Now what they suggest would be really good ... and we should start demanding all, including Fosi start doing the same!

 

[burkm]

It is getting out of hand because "evidence" about any negative or positive effects are hard to get at, if there exists any The problem seems to be, that usually no one can provide "real" measurements one way or the other about the "goods" of each position. The question comes up then, why the manufacturer didn't choose the "best sounding" op amps (objective and subjective) for the job to be done if not for cost reason...

 

[SMen]

It is getting out of hand because "evidence" about any negative or positive effects are hard to get at, if there exists any The problem seems to be, that usually no one can provide "real" measurements one way or the other about the "goods" of each position. The question comes up then, why the manufacturer didn't choose the "best sounding" op amps (objective and subjective) for the job to be done if not for cost reason...

Exactly.

Instead we get lots of NE5532 for cost reason (when in fact there is a very valid reason to design a circuit with this opamp for sound reason). And then, quite possibly, untested expensive opamps proposed as swaps for profit reason ...

I was pleased with the 3e response because it looks like they are trying OPA16xx op amps for an optimized circuit. Whether it measures better (or subjectively sounds) better is to be seen and heard.

But the latter "spirit" is one to encourage!

Post edit: if you look here https://fosiaudio.com/pages/fosi-audio-zd3-balanced-dac and go down to the op amp section, it seems that this circuit does not need to be optimized for any particular op amp ... Is this really the case? A question for the engineers here.

 

[kingkoolkris]

I'm sure someone asked this before but: is there any advantage in using RCA<->XLR cables because my Onkyo AVR doesn't have XLR outs.

 

[Freezak]

I'm sure someone asked this before but: is there any advantage in using RCA<->XLR cables because my Onkyo AVR doesn't have XLR outs.

I did - and was told other than slightly lower gain with XLR there's hardly any audible difference, which is probably true. Still, i went with XLR for that placebo effect and peace of mind, lol.

 

[kingkoolkris]

Placebo and peace of mind is something you should never underestimate in hifi matters, lol.
I'll follow your idea and do the same

 

[harrym13]

She probably did, what she was told, and read it of the screen and didn't tell You that there are no V3 Monos in the warehouse right now...

I ordered some on 7th September and they sent them out start of this week - just gone through customs today I think. So Fosi do have stock it seems!

 

[DavidM1]

I am bamboozled by consumers tempted by op amps. To me, hifi components are about transparency with levels of distortion and noise ideally below the level of human perception. Show me an op amp swap with better measurements and I might be interested but swapping blindly makes zero sense.

On the other hand, I understand completely the motivation for selling op amps.

 

[Deleted member 72219]

I am bamboozled by consumers tempted by op amps. To me, hifi components are about transparency with levels of distortion and noise ideally below the level of human perception. Show me an op amp swap with better measurements and I might be interested but swapping blindly makes zero sense.

On the other hand, I understand completely the motivation for selling op amps.

Op-amp rolling is the new tube rolling. You’re looking for your preferred flavor of distortion coloring, not a perfect signal.

Take a Big Mac and then put something else in it—BBQ sauce, fried onions, ranch dressing, banana peppers, whatever…it’s no longer a, “perfect Big Mac,” it’s your own twist.

ASR crowd doesn’t understand anything other than the perfect Big Mac, but these people want it their way; they’re the Burger King types.

-Ed

 

[SMen]

Op-amp rolling is the new tube rolling. You’re looking for your preferred flavor of distortion coloring, not a perfect signal.

Take a Big Mac and then put something else in it—BBQ sauce, fried onions, ranch dressing, banana peppers, whatever…it’s no longer a, “perfect Big Mac,” it’s your own twist.

ASR crowd doesn’t understand anything other than the perfect Big Mac, but these people want it their way; they’re the Burger King types.

-Ed

The thing though is, this V3 Mono does not seem to particularly like the op amps suggested by Fosi!! Well, the Muses02's anyway, certainly x4. I do not have the Sparkos SS3602 - and I am not sure anyone has raved about any of these choices, or the opa1656 (with the Monos). I have the impression a good job was achieved optimizing them for the NE5532s (as per previous posts) on this page. I've got one more thing to try, and then I'll pop my head above the parapet over on the user impressions!

I am not in anyway saying other circuits are the same case examples ...

 

[DavidM1]

Take a Big Mac and then put something else in it—BBQ sauce, fried onions, ranch dressing, banana peppers, whatever…it’s no longer a, “perfect Big Mac,” it’s your own twist.

Take a clear window and then put a rose coloured tint on it. All you have is a rose coloured window and no longer any real sense of the colours on the other side.

if one isn’t interested in high fidelity why not just listen to a clock radio?

 

[Deleted member 72219]

Take a clear window and then put a rose coloured tint on it. All you have is a rose coloured window and no longer any real sense of the colours on the other side.

if one isn’t interested in high fidelity why not just listen to a clock radio?

This why this is called a subjective matter, because it’s obviously not objective at all.

-Ed

 

[somebodyelse]

Op-amp rolling is the new tube rolling. You’re looking for your preferred flavor of distortion coloring, not a perfect signal.

Take a Big Mac and then put something else in it—BBQ sauce, fried onions, ranch dressing, banana peppers, whatever…it’s no longer a, “perfect Big Mac,” it’s your own twist.

ASR crowd doesn’t understand anything other than the perfect Big Mac, but these people want it their way; they’re the Burger King types.

-Ed

That's not what op-amp rolling usually does though - usually there is little to no real difference. Sometimes it causes oscillation which is just bad, and risks damage. People will think they hear a difference due to well known psychological effects that controlled listening tests are designed to avoid.

For your analogy the op-amp rolling is like having a load of identical sauces with different labels, plus a few that have gone bad and might give you food poisoning. Here we suggest that if you want to change the flavour you should start with a known good recipe and make known changes to the ingredients - use a plugin like PKharmonic to create your preferred distortion profile.

 

[burkm]

It is getting out of hand because "evidence" about any negative or positive effects are hard to get at, if there exists any. The problem seems to be, that usually no one can provide "real" measurements one way or the other about the "goods" of each position. The question comes up then, why the manufacturer didn't choose the "best sounding" op amps already (objective and subjective) for the job to be done if not for cost reason...

I ordered some on 7th September and they sent them out start of this week - just gone through customs today I think. So Fosi do have stock it seems!

They might have restocked already... (News are always "old" because of existing time delay...)

 

[Mort]

If selling useless op-amps to goldeneared consumers helps them achieve a lower price point on this otherwise audibly perfect device, I'm all for it.

 

[ninetylol]

OP amp jugglers really are the new clowns of audio

 

[burkm]

I don't think, if they achived a lower price point because of this, They probably don't know, how much of those they are selling and economic wisdsom usually dictates, that Your selling price should be independent of other sales, if You don't know otherwise. To my understanding it is additional income...

 

[SaltyCDogg]

Interesting that they're now selling this with some cooling fans.

https://a.aliexpress.com/_EuVQSXj

 

[burkm]

I believe they try to circumvent any "turbulences" among (potential) users due to those "rumors" of high temperatures generated by the V3 monos during use.
They are beeing sold (sometimes) on several marketplaces for similar ones at almost 1/2 the Fosi Audio price, but their size is somewhat special: 125 mm.
A 120 mm fan with USB connection should be fine too...
Note: No info about the additional noise generated and amperage needed by those fans.... An external USB power supply must be used.