Fosi Audio V3 Mono Amplifier Review

[staticV3]

@amirm this should be titled "...dbW" at the top?

The graph shows Vrms.

 

[Head_Unit]

The graph shows Vrms.

I'll believe it's Vrms but unless I'm going blind it doesn't actually say that, like the one right below which says "(Watts)." ?!?

 

[staticV3]

I'll believe it's Vrms but unless I'm going blind it doesn't actually say that, like the one right below which says "(Watts)." ?!?

Correct. It's a graph with an unlabeled y-axis, which nonetheless shows Vrms.

 

[Fosi Audio]

I am guessing that since those power supplies are like a standard item for computers (I think??) integrating into a fairly larger enclosure might increase the cost more than we might think offhand. I'd be interested in @Fosi Audio's comments about that.


@amirm this should be titled "...dbW" at the top?

For our V3 series, we will maintain the compact chassis design, but for other series, such as the ZA series, we will use larger enclosures.

 

[Fosi Audio]

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

This is a follow-up on the 48V/10A power supply. Our supplier Huntkey has provided us with a test report for this power supply, along with a video of the actual test, which you can review below. This power supply can indeed operate stably at a 10A current.

Noise & ripple test also included. @SMen

 

[Guddu]

This is a follow-up on the 48V/10A power supply. Our supplier Huntkey has provided us with a test report for this power supply, along with a video of the actual test, which you can review below. This power supply can indeed operate stably at a 10A current.

Noise & ripple test also included. @SMen

View attachment 368520View attachment 368521View attachment 368522View attachment 368523

Assurance…. Excellent.

 

[jvdburgt]

I contemplated upgrading my package to their SP601 speaker/amp package, but I haven't been able to find anything on them aside from a factory youtube video. Were you able to get any additional details on them?

Nope, not yet, so it’s a bit a jump in the dark.

However, on their KS page they stated more details will be released next week.

 

[MCH]

This is a follow-up on the 48V/10A power supply. Our supplier Huntkey has provided us with a test report for this power supply, along with a video of the actual test, which you can review below. This power supply can indeed operate stably at a 10A current.

Noise & ripple test also included. @SMen

View attachment 368520View attachment 368521View attachment 368522View attachment 368523

Fantastic Fosi. Is it possible to share the full report? Thanks!

 

[fredreadrick]

My thoughts exactly.I have an unopened tube sitting at home.

But V3 is not like cpu that heatsink drops directly on top. Just like ZA3 that needs to slide to put in place. Thus rubbing the thermal paste and not maximizing it's heat desipitating quality.

 

[Lednek]

But V3 is not like cpu that heatsink drops directly on top. Just like ZA3 that needs to slide to put in place. Thus rubbing the thermal paste and not maximizing it's heat desipitating quality.

I have seen a video with disassembly (Williston Audio Labs. You can see the thermal compound they used on the heat sink. It looks like there is enough clearance between the heatsink and enclosure. The appropriate contact is created when the two screws on the bottom of the case are tightened into the heatsink.

 

[Lednek]

But V3 is not like cpu that heatsink drops directly on top. Just like ZA3 that needs to slide to put in place. Thus rubbing the thermal paste and not maximizing it's heat desipitating quality.

 

[SMen]

This is a follow-up on the 48V/10A power supply. Our supplier Huntkey has provided us with a test report for this power supply, along with a video of the actual test, which you can review below. This power supply can indeed operate stably at a 10A current.

Noise & ripple test also included. @SMen

View attachment 368520View attachment 368521View attachment 368522View attachment 368523

So that is interesting, thank you @Fosi Audio . It looks like noise @240Vac is much lower than spec. Excellent.

 

[Billy Budapest]

Apparently it is?

Bi-amping 101

This article provides a quick look at how bi-amplification works. The conventional scheme is to split the signal into two frequency bands before the power amplifiers that drive the speakers. The bass (LF) amp sees only LF signals and drives only the LF driver (woofer). The treble (HF) amp sees...

www.audiosciencereview.com

Bi-amp, bi-wire, passive crossover & active crossover interaction

My background is pro audio, where bi/tri-amp is well known. It requires an active crossover, feeding separate amplifiers, such that each speaker (sub/woof/tweet) receives only it's intended frequency range. I see quite a few consumer loudspeakers with two sets of terminals that default to being...

www.audiosciencereview.com

No, it isn’t. The post I was responding to posited that biwiring speaker drivers using only the amp in a receiver would result in each driver performing more efficiently because it has a “dedicated source” (in this case, it’s not a separate source but instead a separate wire). However, that is not true. Take a basic Physics course to learn why.

 

[DavidM1]

Fosi keeps demonstrating how to do business in the post showroom era.

 

[somebodyelse]

But V3 is not like cpu that heatsink drops directly on top. Just like ZA3 that needs to slide to put in place. Thus rubbing the thermal paste and not maximizing it's heat desipitating quality.

The place for Arctic Silver would be between the chip and the heat spreader block as the heat transfer is over a small area. The much larger area between the heat spreader and the case is less critical, and the rubbing removing the thermal paste is probably helps in avoiding there being too thick a layer of paste.

 

[Lee T]

I've just noticed that Zeos of Zreviews posted the following 6 days ago.
"I have an issue with one [of my V3 Monos] right now. Need to see if its the amp or the Opamps I put inside."
Reply to @andrewdoan1525 which is the 4th most recent comment at time of me posting this
I thought it was worth noting as along with Erin managing to smoke one, that might be 2 dead reviewer amps in just a few weeks out of about 10 reviews (20 amps) I'm aware of.

 

[Sputnik]

I've just noticed that Zeos of Zreviews posted the following 6 days ago.
"I have an issue with one [of my V3 Monos] right now. Need to see if its the amp or the Opamps I put inside."
Reply to @andrewdoan1525 which is the 4th most recent comment at time of me posting this
I thought it was worth noting as along with Erin managing to smoke one, that might be 2 dead reviewer amps in just a few weeks out of about 10 reviews (20 amps) I'm aware of.

Erin tortured that poor little amp to death, and Z has been poking around in it with his greasy sausage fingers.

If another reviewer smashes 2 more units with a hammer, you're gonna tell us '4 out of 20 died'?

 

[quocheiser]

I've just noticed that Zeos of Zreviews posted the following 6 days ago.
"I have an issue with one [of my V3 Monos] right now. Need to see if its the amp or the Opamps I put inside."
Reply to @andrewdoan1525 which is the 4th most recent comment at time of me posting this
I thought it was worth noting as along with Erin managing to smoke one, that might be 2 dead reviewer amps in just a few weeks out of about 10 reviews (20 amps) I'm aware of.

Do you have a timestamp for when he says that?

 

[Lee T]

Erin tortured that poor little amp to death, and Z has been poking around in it with his greasy sausage fingers.

If another reviewer smashes 2 more units with a hammer, you're gonna tell us '4 out of 20 died'?

I'm inclined to agree that there's not much so far to indicate fault with the amps themselves. I don't know how far or reasonably Erin tried to stress the amps or how ham-fisted Zeos was or whether the issue isn't with the op-amps.

I'm more raising this as a sort of "note and move on" thing. I'd be interested to know more about Erin's test and what Zeos concludes. I think it is worth being aware of these examples in case a pattern emerges. I'm not expecting it will.

Do you have a timestamp for when he says that?

He said it in a comment after the video was put up, not in the video itself.

 

[quocheiser]

I'm inclined to agree that there's not much so far to indicate fault with the amps themselves. I don't know how far or reasonably Erin tried to stress the amps or how ham-fisted Zeos was or whether the issue isn't with the op-amps.

I'm more raising this as a sort of "note and move on" thing. I'd be interested to know more about Erin's test and what Zeos concludes. I think it is worth being aware of these examples in case a pattern emerges. I'm not expecting it will.


He said it in a comment after the video was put up, not in the video itself.

Gotcha.
Yeah from what I could gather from all the available reviews, the V3Ms get a bit warmer than their other models.
Looking forward to Fosi's reply to Zeos on the issue.