Fosi Audio V3 Mono Amplifier Review

[Bleib]

it's very mediocre review, much needed measurements, but overally mostly irrational complains (this amp has 200W, oh i like 500W! Thats how quirky I'am - might be the stupidest thing said by the reviewer i've heart this year) Also measurements without any comments or context: oh the graph look like this, now f*ck off. And also Fosi stop sending mi these i don't like to review this amps (Wtf?). Oh, and one got fried, haha, so funny. I haven't seen such an unfair review in a long time.

But apart from the diva rewiever, looks like two power supplies is the way to go (5A or more).

Erin is easily among the better reviewers because he actually cares to measure, usually he has more on his website but so far nothing on this
I don't care that much that one of the amps got fried because when watching movies or listening to music it be anywhere near the same load as his tests..

 

[Negatywny]

Erin is easily among the better reviewers because he actually cares to measure.

I saw almost all his reviews and cant remember as bad as this one. It seems that even a review based on measurements can be covered with subjective, irrational gibberish if for some reason someone feels the need to do so:

This is small amp, i don't need small amps, so this is completely useless device, look at me throw it to the trash can, haha.

I don't care that much that one of the amps got fried because when watching movies or listening to music it be anywhere near the same load as his tests..

We know that, but most people probably doesn't know that, so his review is very very misleading.

 

[Sokel]

We know that, but most people probably doesn't know that, so his review is very very misleading.

People are all over the place so it's good to point out that it's not sensible to drive subs with these for example.
Or,in a system with EQ filling dips (not a nice thing to do but people do it anyway) demands can skyrocket and it won't be far from this if combined with the typical already insensitive small 2-ways.

Anything exposing potential weaknesses is good for the potential buyer in my book.

 

[Negatywny]

of course, but this is the contekst he should have provided, not you or enyone else on some obscure forum. From hes review it only look like: hey i plugged this amp, tested it and it fried, so it's firy little amp.

Spoiler

and definetely he should have statet that normal usage is nowhere neer 150% constant load for several hours. As Amirm aleways does in this situations.

Also i understand that the problem was mostly using one power supply for two amps, that what fried it. With two separates everything was grate?

 

[Talisman]

@Fosi Audio 's silence these days and the new measurements have convinced me to change reward from single 48V 10(?)a to double 48v 5a

 

[galego100]

@Fosi Audio 's silence these days and the new measurements have convinced me to change reward from single 48V 10(?)a to double 48v 5a

I change it too

 

[Sokel]

Also i understand that the problem was mostly using one power supply for two amps, that what fried it. With two separates everything was grate?

The problem was not the PSU,the problem was heat by driving it repeatedly to/or near to it's physical heat dissipation limits.
Let's not forget the size (hence the heat dissipation area) .

 

[Boppo84]

Yeah, it's a little worse than not fair to look for the limitations, push it over the boundries and than complain that it can't handdle it. No surprise there. But at the same time something that might have been prevented by some form of thermal protection.

 

[Sokel]

Yeah, it's a little worse than not fair to look for the limitations, push it over the boundries and than complain that it can't handdle it. No surprise there. But at the same time something that might have been prevented by some form of thermal protection.

The chip itself HAS thermal protection,he states so as it kicked in some times. TI's data sheet is clear about it.
But components around it (caps,resistors,etc) don't have such protections.Anything can fail if not spec'ed for such temperatures.

Edit:No one in the right mind expects mil spec'ed,ultra low ppm (so their values don't drift) resistors for example at this price range.

 

[Negatywny]

The problem was not the PSU,the problem was heat by driving it repeatedly to/or near to it's physical heat dissipation limits.

Yeah, but the protection kicked in several times during using one power supply for two amps (as for other reviewer posted here), and then one amp fried? With one power supply per amp everything worked fine.

 

[Sokel]

Yeah, but the protection kicked in several times during using one power supply for two amps (as for other reviewer posted here), and then one amp fried? With one power supply per amp everything worked fine.

It's about time.No matter what PSU used,if it could bring the amp to/near it's limit it was just a matter of time.
Speakers/load demands and amp tries to deliver.If there's enough juice it does,the PSU is just there to follow.

 

[SMen]

I think it's a useful review - interesting about his ABX Comparator - there is a review of it here. https://www.dagogo.com/audio-by-van-alstine-abx-comparator-review-part-1-audio-store-wiring/

He demonstrates graphically the effect of PFFB between the V3 mono and the ZA3 and then goes on to challenge whether he can actually hear it / any differences using the comparator! The frequency shaping of the Dayton valve amp he refers to (boosted lows for warmth) was both audible and measurable, but for him V3 vs ZA3 not.

Seems like good stuff.

I think he over does the failure of one unit as I do get the impression he might have been on a bit of a mission to stress them to death! Reassure himself vs those other 500w beasts he has and loves ...

But we still need @Fosi Audio to confirm about this 10a power amp rating, whether super early birds can decide on two 5a instead, and indeed what the revised / finalized stretch goal rewards will be ...

 

[Negatywny]

No matter what PSU used,if it could bring the amp to/near it's limit it was just a matter of time.

isnt that quite the opposite?
One psu two amps can't drive amp to its limits, but can fry it - but one psu one amp can drive the amp to its limits and doesn't fry it...

 

[Sokel]

isnt that quite the opposite?
One psu two amps can't drive amp to its limits, but can fry it - but one psu one amp can drive the amp to its limits and doesn't fry it...

No,the amp doesn't care about the PSU as long as it is adequate.
Amp's protection are overheat,undervoltage,overvoltage and overcurrent.
As long as these are in check doesn't matter.
If the shared PSU could not follow the voltage demand the amp would just go into protection (that's on paper at least).

There is a chance for the PSU to go crazy too but that would be evident.

 

[mike70]

Might as well link the video review here too

Erin's review is very ... weird. Like he doesn't want to review it.
The burned one, was abused or he suspects thermal management/ USPS isn't enough/etc?
120 watts with 8 ohms is low? I'm very (very) happy with 70 watts in 8 ohms.

What I want in an amplifier is transparency to the source ... in that way is a good amplifier and you can prove it with measurements. Then add other facets, like construction, features, power, ... I saw many reviews from Erin and that kind of stuff was stated clearly, but this one is messy, sometimes with near incoherent or "blurred" concepts.

Maybe I'm wrong (I'm open to that, of course) but this is the worst Erin review ever.

 

[DSJR]

I saw almost all his reviews and cant remember as bad as this one. It seems that even a review based on measurements can be covered with subjective, irrational gibberish if for some reason someone feels the need to do so:

This is small amp, i don't need small amps, so this is completely useless device, look at me throw it to the trash can, haha.


We know that, but most people probably doesn't know that, so his review is very very misleading.

I think that fried amp should be sent back for repair - a little less to junk and maybe Fosi can see where the fry-up happened. Incredible what can be done in a tiny box (with external power brick) and in fairness, so many 'enthusiast high end' amps don't like being stressed either - does anyone remember the D'Agostino mega-bocks mono that went awol during a Stereophile test to the point that LA (I think it was) aborted the continuous third?-power test on the other?

I agree that in this case, Erin was a bit dismissive to put it politely and as said above, not seemingly too keen on reviewing it maybe, but there does seem to be a mentailty with these tiny chip amps that they're landfill in the making a few years down the line as they'll be totally uneconomic to service if they go wrong. Just treat them with some care and you/we may be fine longer term.



I'm reminded of the days when 'pocket rocket' sporty GTI type cars were the in thing in late 80's - early 90's UK motoring. Point-n-squirt the requirement of any aspiring yuppie type of the period. Sure they had spectacular on-road abilities compared to sprty small saloons of eralier times, but the limits on-road were very tightly defined and if you pushed too far, you'd be in a hedge or spinning to face the other way on a lightly damp road (as happened to two Peugeot 2-5GTI 1.9 owners I once knew - the 1.6 was okay but not the 1.9 which traded a more supple suspension for a straight-line performance and some dry-road handling)

 

[SMen]

Erin's review is very ... weird. Like he doesn't want to review it.
The burned one, was abused or he suspects thermal management/ USPS isn't enough/etc?
120 watts with 8 ohms is low? I'm very (very) happy with 70 watts in 8 ohms.

What I want in an amplifier is transparency to the source ... in that way is a good amplifier and you can prove it with measurements. Then add other facets, like construction, features, power, ... I saw many reviews from Erin and that kind of stuff was stated clearly, but this one is messy, sometimes with near incoherent or "blurred" concepts.

Maybe I'm wrong (I'm open to that, of course) but this is the worst Erin review ever.

I think the key is in his reference to 'big boy amplifiers' he uses in the very last section - his 500 watt into 4 ohm's he uses in his main rig. A more telling comparison would have been a/b'ing with those. This is where it gets weird - like - do those not sound 'just like amplifiers' too when he talks about the sound.

So yes mixed up, but frying one solves the problem.

 

[Rafaille]

@Fosi Audio 's silence these days and the new measurements have convinced me to change reward from single 48V 10(?)a to double 48v 5a

Same here, for the same reasons

 

[Pareto Pragmatic]

The burned one, was abused or he suspects thermal management/ USPS isn't enough/etc?

He was running 48v 10amp test tones into one amp. While the chip is rated for that power level, we all know test tones are a lot harder on equipment than music. I would guess it was not the chip that let out the magic smoke, but some other component. And I doubt there would be issues with running 2 amps off that power supply in terms of things going "poof".

If I were to get a pair, I would go with two separate 48v 5amp power supplies. I really don't get the single power supply approach on monoblocks.

 

[Cardone]

I also changed from 1x10A to 2x5A..