Fosi Audio V3 Mono Amplifier Review

[Roger285]

This is disappointing if true, but I'm going to wait for Fosi's response before trying to change my KS reward. I don't plan on placing the monoblocks right next to my speakers so I was fine with a splitter if the single PSU had identical performance, but if it doesn't, I'll definitely want the two 5A power supplies. I don't really want to shell out another $100 for a second 10A power supply.

It seems strange that no one else has come across this discrepancy yet - seems like it would be an important part of the measurements?

FYI, you may already have seen this, but Fosi has this to say regarding the amps performance with the different power supplies:

Based on our measurement, using a 48V/10A power supply does not significantly increase power output compared to a 48V/5A power supply. Other parameters, such as signal-to-noise ratio, THD, and frequency response, are also virtually identical. Therefore, there is no noticeable difference between the two options in terms of your user experience. We are offering this one-to-two power configuration option for more flexible system building. Of course, by using one less power supply unit, you can save space and achieve a neater system setup.

 

[SMen]

FYI, you may already have seen this, but Fosi has this to say regarding the amps performance with the different power supplies:

Based on our measurement, using a 48V/10A power supply does not significantly increase power output compared to a 48V/5A power supply. Other parameters, such as signal-to-noise ratio, THD, and frequency response, are also virtually identical. Therefore, there is no noticeable difference between the two options in terms of your user experience. We are offering this one-to-two power configuration option for more flexible system building. Of course, by using one less power supply unit, you can save space and achieve a neater system setup.

This is the point really - it has the same brand and serial number of a 48v6.3A model so clarification needed surely? And this general issue or question has cropped up a few times in different threads, including this one https://www.audiosciencereview.com/forum/index.php?threads/aiyima-a70-stereo-amplifier-review.52830/

https://www.audiosciencereview.com/...o-v3-mono-amplifier-review.53474/post-1963060 this review does strike me as being closer to 10A though - but someone with better knowledge than me might chip in at what their measurements ought to suggest. The tester was puzzled though and referred to some kind of 'limiting' at play possibly.

Interesting to watch the testing.

 

[drmevo]

The Fosi power supplies do seem expensive compared to Aiyima's GaNs, but equally if the innards are closer to 10A than 6.3A we ought to know if the Fosi model is modified or more highly specified in some way than the ones @Psinet referred to. I don't have 2 ohm speakers that is for sure! But it's the principle.

It's probably a pain, but if these power supplies are going be supplied as separate products it would indeed be useful to know / verify the measurements I agree.

I might've misinterpreted the review but he seemed to imply that it wasn't hitting its power rating for 8 or 4 Ohm either. That would be my real concern.

 

[antcollinet]

Not a bad review

based only on subjective opinions.

Oxymoron

 

[SMen]

I might've misinterpreted the review but he seemed to imply that it wasn't hitting its power rating for 8 or 4 Ohm either. That would be my real concern.

They so often do. The question for me really is why? They are not too far short but I really weighed up which power supply option to get. If we had a verified power and ripple figure for power supplies I think it would be interesting. But there is a big difference between 48v6.3 amps and 48v10 amps. If I am not mistaken it is 302watts vs 480 watts.

 

[rvsixer]

I wonder what is the prize for the stretch goal.

Listed under Campaign->Stretch Goals on the Kickstarter page.

 

[EddNog]

Listed under Campaign->Stretch Goals on the Kickstarter page.

We’re wondering what the revised stretch goal rewards will be as they have said they are planning to improve on what’s listed because a single MUSES op-amp isn’t very useful when you’re buying two amps.

-Ed

 

[SMen]

Listed under Campaign->Stretch Goals on the Kickstarter page.

In the email I received today these might be changing.

We’re wondering what the revised stretch goal rewards will be as they have said they are planning to improve on what’s listed because a single MUSES op-amp isn’t very useful when you’re buying two amps.

-Ed

nor a single xlr cable! Mind you there is a difference, as you would need 4 op amps not 2! ... language issue here in the marketing methinks

 

[EddNog]

In the email I received today these might be changing.

nor a single xlr cable!

For some odd reason I thought it was implied to be one pair of cables but you make a good point if it was indeed just a single one.

-Ed

 

[SMen]

For some odd reason I thought it was implied to be one pair of cables but you make a good point if it was indeed just a single one.

-Ed

I know confusing! I actually just edited my reply to reinforce your point!

We shall see.

 

[EddNog]

I know confusing! I actually just edited my reply to reinforce your point!

We shall see.

Yeah…although the op-amp thing is arguable because they said that theoretically you could just do one of the two gain stage pieces (per amp) and it would still work, just less of an effect. Either way I can think of better things for them to give us. The XLR cables, even a pair, does nothing for the backers who don’t run a balanced chain (I do, so not my problem, but then I already have plenty of spare XLR cables on hand as-is).

-Ed

PS Admins pls don’t thread ban me, I’m just trying to talk about stretch crowdfunding goals, not the subject matter whose name shall not be mentioned.

 

[SMen]

Yeah…although the op-amp thing is arguable because they said that theoretically you could just do one of the two gain stage pieces (per amp) and it would still work, just less of an effect. Either way I can think of better things for them to give us. The XLR cables, even a pair, does nothing for the backers who don’t run a balanced chain (I do, so not my problem, but then I already have plenty of spare XLR cables on hand as-is).

-Ed

PS Admins pls don’t thread ban me, I’m just trying to talk about stretch crowdfunding goals, not the subject matter whose name shall not be mentioned.

Ditto.

Regarding the cables people can choose RCA.

There are a few things for Fosi to 'tidy up' for clarification in terms of marketing, and indeed some technical aspects. They do seem to get there though, so I'm looking forward to these revisions and updated info.

 

[drmevo]

They so often do. The question for me really is why? They are not too far short but I really weighed up which power supply option to get. If we had a verified power and ripple figure for power supplies I think it would be interesting. But there is a big difference between 48v6.3 amps and 48v10 amps. If I am not mistaken it is 302watts vs 480 watts.

Could this be an RCA vs. balanced connection issue? I'm clueless on this stuff but that seems to be the difference in the way Amir tested vs. the Williston Audio video.

I don't want to make a mountain out of a molehill, it could be there is a simple explanation and everything is fine. I'm trusting Fosi when they say the 10A is essentially the same as two 5A, or at least that they'll make it right if it's not currently.

 

[AndyLu]

Oxymoron

Oxymoron? Not really. Except if you take things extremely literaly. You nitpicked quotes from my post out of context. My qualifier 'not a bad review (if you can call it that)' was not meant about the quality of the review itself, but about the quality of the Fosi amp (based on the reviewers subjective opinion). I thought that was pretty clear from my whole post . I don't see an oxymoron there.

 

[SMen]

Could this be an RCA vs. balanced connection issue? I'm clueless on this stuff but that seems to be the difference in the way Amir tested vs. the Williston Audio video.

I don't want to make a mountain out of a molehill, it could be there is a simple explanation and everything is fine. I'm trusting Fosi when they say the 10A is essentially the same as two 5A, or at least that they'll make it right if it's not currently.

It is not RCA vs. balanced I extremely doubt, but it should not be about trust! On all places but here on ASR!

A simple explanation is probably due here

 

[antcollinet]

Oxymoron? Not really. Except if you take things extremely literaly. You nitpicked quotes from my post out of context. My qualifier 'not a bad review (if you can call it that)' was not meant about the quality of the review itself, but about the quality of the Fosi amp (based on the reviewers subjective opinion). I thought that was pretty clear from my whole post . I don't see an oxymoron there.

I know - I was just having fun (as I'd hoped the emoticon would indicate )

 

[AndyLu]

I know - I was just having fun (as I'd hoped the emoticon would indicate )

Yeah sorry, I am a bit emoticon dyslexic

Edit: Changed typo in dyslexic (go figure )

 

[antcollinet]

Yeah sorry, I am a bit emoticon dyslectic

No problem - and you are absolutely correct: I did misquote your post.

 

[rvsixer]

We’re wondering what the revised stretch goal rewards will be as they have said they are planning to improve on what’s listed because a single MUSES op-amp isn’t very useful when you’re buying two amps.

-Ed

Listed under Campaign->Stretch Goals on the Kickstarter page.
In the email I received today these might be changing

Well personally I think that the kickstarter page will be one of the first places they list the revised rewards, and also that they won't change the rewards posting location (or keep a revision history on them). Its still where I will be looking out for them.

 

[Psinet]

When Big D (Williston) did the max power dyno run at 1% distortion at 4 ohms on 2x mono amps using a y-splitter on the "10A" power supply, both amps engaged a safety power off. When he used a single amp on the "10A" at 4 ohms 1% distortion, it did not do a safety power off.