Fosi Audio V3 Mono Amplifier Review

[tmtomh]

Our hearing apparatus changes with everything, even during the same day it reacts differently in the morning or in the evening, this affects the way we hear how the speakers sound.

Indeed it does.

 

[Bruce Morgen]

I would think a lower voltage(36V) power supply would be easiest on the chip? But you would loose considerable output unless you were driving low impedance speakers. The higher current powered supply might get you some longevity from the powered supply itself, but wouldn't effect the amp chip. It will only pull what it needs. You could hook that up to a 48v 100A power supply and be fine. Likewise, driving low impedance speakers would be harder on the amp chip because it's pulling more current.
TLDR. both higher voltage and amperage will tax the chip. Only the effect of the voltage is controllable via the power supply providing its not starving the amp of current.

For the umpteenth time, I hereby testify that my two four year old A07s are still performing flawlessly after spending most of those years powered up 24/7 on 48VDC, despite their obviously deficient thermal design and 50V-rated Nichicon filter caps. Real world music listening is a far cry from rigorous bench testing with steady input from a signal generator, and in my particular use case (or others like it) even less-than-optimal little "chip amps" like my now-elderly A07s are likely to thrive long-term.

 

[Lednek]

I don't see it as a problem either. Just trying to answer the question, if for no other reason than theoretical accuracy. I'll be running mine on 48v for sure.

 

[Bruce Morgen]

I don't see it as a problem either. Just trying to answer the question, if for no other reason than theoretical accuracy. I'll be running mine on 48v for sure.

Fair enough -- thanks!

 

[Fosi Audio]

@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

Sorry, May 1st to 5th are holidays here, so we were unable to respond promptly to your inquiries. Our R&D colleague on duty today sent the test result for the 48V/10A power supply, indicating that it can operate stably at 10A.

Additionally, our supplier Huntkey will provide us with the relevant test report for this power supply after they resume work tomorrow, and we will post update then.

 

[Talisman]

Sorry, May 1st to 5th are holidays here, so we were unable to respond promptly to your inquiries. Our R&D colleague on duty today sent the test result for the 48V/10A power supply, indicating that it can operate stably at 10A.

Additionally, our supplier Huntkey will provide us with the relevant test report for this power supply after they resume work tomorrow, and we will post update then.

View attachment 367686

Thank you for your response and reassurances, always efficient and punctual.
At the moment, for my personal peace of mind, I prefer to maintain the dual power supply configuration, but I really appreciate your availability

 

[SMen]

Sorry, May 1st to 5th are holidays here, so we were unable to respond promptly to your inquiries. Our R&D colleague on duty today sent the test result for the 48V/10A power supply, indicating that it can operate stably at 10A.

Additionally, our supplier Huntkey will provide us with the relevant test report for this power supply after they resume work tomorrow, and we will post update then.

View attachment 367686

Thank you for your clarification and follow up on this.

Could you publish noise and ripple from your supplier Huntkey also?

 

[quocheiser]

Sorry, May 1st to 5th are holidays here, so we were unable to respond promptly to your inquiries. Our R&D colleague on duty today sent the test result for the 48V/10A power supply, indicating that it can operate stably at 10A.

Additionally, our supplier Huntkey will provide us with the relevant test report for this power supply after they resume work tomorrow, and we will post update then.

View attachment 367686

So the power supply can output 10A current for a few seconds during a rather short 'test'.
What can we actually take away from this brief video?
How dependable is this kind of testing to gauge long-term performance and stability?

 

[Fosi Audio]

Please rest assured, we have conducted durability tests to ensure that this power supply can stably output 10A current for a long time.

So the power supply can output 10A current for a few seconds during a rather short 'test'.
What can we actually take away from this brief video?
How dependable is this kind of testing to gauge long-term performance and stability?

 

[iLoveCats]

Is everyone that switched to two 5 amp supplies gonna switch back? Fosi has always provided the receipts when pressed. Great job you guys.

 

[drmevo]

Is everyone that switched to two 5 amp supplies gonna switch back? Fosi has always provided the receipts when pressed. Great job you guys.

I don't think I will unless some new information comes out showing an added benefit to the 10A. The Aiyima I have in my system temporarily uses a 36V 6A PSU which is plenty of power for my medium-sized room, and that is a stereo amp.

Plus, if the 10A were to die, which is not unheard of with this type of PSU, you're out ~$100 for a new one. If a 5A dies, you're only out ~$50, although I suppose you do have twice the chance of that happening.

 

[amix]

I have heard, the chip would be current limited at some value below 10A. Does that mean, that the 10A PSU is a waste of money, because the current can't get through anyway?

 

[antcollinet]

I have heard, the chip would be current limited at some value below 10A. Does that mean, that the 10A PSU is a waste of money, because the current can't get through anyway?

This chart is from the datasheet from the PBTL ratings

To put out 450W into 2ohm, then it needs to deliver 15A.
240W into 4ohm needs 7.74A - so here we are voltage limited with the 10A supply.

(Oops - corrections made..)

So no, I don't think the chip is limiting the current.

.

 

[quocheiser]

Please rest assured, we have conducted durability tests to ensure that this power supply can stably output 10A current for a long time.

Thanks very much for that reassurance. It is great to have that in writing and reflects very well that you are prepared to do that.
As an aside: I am looking very forward to seeing the footage from the Fosi Audio stand at Munich High End 2024!

 

[quocheiser]

I have heard, the chip would be current limited at some value below 10A. Does that mean, that the 10A PSU is a waste of money, because the current can't get through anyway?

Where did you hear that?
If Fosi could confirm that their design is not current limited that would also be great.

 

[MCH]

The over current protection of the chip itself is programmable, and the values possible are high, even the lower ones.

 

[amix]

Where did you hear that?
If Fosi could confirm that their design is not current limited that would also be great.

I think it was in this thread, a few pages back.

 

[jvdburgt]

I couldn’t help myself and added 2x V3M and the SP601 speakers to my previous pledge for 3xV3M.

I have a 5.1 setup with a Marantz S6012 as receiver. My speaker setup is as follows:
- Fronts: Monitor Audio GS10 (relatively modest speakers)
- Center: Monitor Audio GSLCR
- Surrounds: the idea is to put the SP601 as surrounds.

Now, with 5 V3 Mono’s to play with, should I go for:
A. Each speaker its own amp
B. Bi-amp the fronts, and drive the surrounds with the S6012’s internal amp?

Of course I’ll experiment, but happy to hear your thoughts on this

 

[rvsixer]

I see they provided specs on the SP601 speakers. On paper they look quite good, anyone has an idea how they perform against well known speaker brands (like Monitor Audio)?

Now that you have the SP601's coming your way, suggest sending one (and your comparison speaker) in to ASR for testing to answer the question .

 

[jvdburgt]

Now that you have the SP601's coming your way, suggest sending one (and your comparison speaker) in to ASR for testing to answer the question .

Haha! I think I’ll take the egoistic route here, and hope that Fosi will send a fresh pair to ASR anyway