Fosi Audio V3 Mono Amplifier Review

[sikahr]

Power thermal review is up:

At the You tube channel Scientific Audiophile
today You can expect review of V3 Mono @ long term (significant) continuous power regarding thermal behavior using 48V 10A PSU.

 

[Bleib]

It's live but I'm gonna skip it, not gonna notice any difference from what I already have, Topping PA5 II+

 

[iLoveCats]

The 2 amps and 10 amp power supply early bird special on kickstarter is half gone already. Only 100 available. $218! Crazy

 

[norcalscott]

Got in for the 2x units and the 10 Amp power supply. At $218 it is a no brainer for me.

 

[SMen]

The 2 amps and 10 amp power supply early bird special on kickstarter is half gone already. Only 100 available. $218! Crazy

It does look as if they put the price up a bit.
Adding 30% you get $283. It will be interesting to see how it slows down once the early bird offers are gone.

 

[EddNog]

Already have two 48V/10A PSUs so got in on the 30% off for a pair with 5A PSUs and will just use the 5A ones to sell my ZA3s.

-Ed

 

[rcalderon]

2 X Mono V3
2 X 48V/10A

Done deal!

I want to buy 2mono v3 but there is 2 options : with two 48v/5a or One 48v/10a.

Why two 48/10a… Can you help with this???

 

[spandy]

I want to buy 2mono v3 but there is 2 options : with two 48v/5a or One 48v/10a.

Why two 48/10a… Can you help with this???

after you select that option you can then add on another 10a psu on the next page.

 

[SMen]

I want to buy 2mono v3 but there is 2 options : with two 48v/5a or One 48v/10a.

Why two 48/10a… Can you help with this???

Play safe with one 48v/10a while you can ... but yes - you can on the next page as @spandy says.

 

[YesChickenNuggets]

Power thermal review is up:

Haha. This guy is engineering dad funny. Amir should implement more engineering dad jokes in ASR videos.

Also @Fosi Audio , Let's talk about the thermal design. It's better than an internal heatsink, but the linkage is still not good. That tube extrusion is not flat internally, so the distribution block makes poor contact with it. That increased distance is bad for heat transfer. We should instead move to a clam shell, that way you can have a perfectly milled surface to drop the chip against, doing away with the spreader block altogether. Reducing the distance is key to good heat conduction. It also saves on material.

It's a real pain to work with thermal paste in the current design, it slathers paste all across the bottom when you slide in and out. You waste paste, and it's kinda gross looking.

 

[TheBatsEar]

It's live but I'm gonna skip it, not gonna notice any difference from what I already have, Topping PA5 II+

Me too.

Also Kickstarter told me three times i couldn't register because the email register link was expired.

 

[TheBatsEar]

I want to buy 2mono v3 but there is 2 options : with two 48v/5a or One 48v/10a.

Why two 48/10a… Can you help with this???

Some said they wanted more amps to have some extra power. Note that Amir testet with the 5A power supply.
In my opinion it should be enough, unless you expect to constantly be on the edge of it's power delivery capability.

 

[Guddu]

@Fosi Audio I will never stop criticizing you for this unfortunate choice of advertising replaceable op amps which lead to these endless and very boring discussions on replacing opamps.... I understand that this brings you a lot of sales to fans of the design mess, but it also leads to these pages of boredom

True.
But they have to make sales going as well…..
They are in it for business after all.

 

[StereoHz]

Fastest overfunded project ever? I got 2 amps with 2 48v/5a psu as I plan to keep them very close to my speakers and run long XLR's. Looking forward to these.

 

[Cal_Cobra]

Whew, got a pair of Fosi V3 mono blocks w/separate power supplies on the early bird discount!

As of 4/20 @ 8:11AM PST here's where they stand (long ways from those upgraded MUSE opamps

 

[Grierts]

 

[StefanC]

Got two units. Hope they can deliver them in June, because I--like many others, I suppose--am travelling at the beginning of July.

 

[Cal_Cobra]

The way i see it:

• GaN is smaller, this is mainly why it was developed.
• It might run cooler, because of slightly higher efficiency than regular switching supplies and far higher switching frequency.
• It has no impact on fidelity.
• It costs more.
• If you buy it, your hifi buddies will say "Ohh, GaN! You must be from the future!"
• If i meet you i will say "Ohh boy, GaN, you must have money to burn."

So yes, there are benefits to GaN power supplies. I'll get a 100W USB GaN power supply for my backpack eventually, as it seems Thinkpads and every other mobile device uses USB-C now for charging. But i see no benefit for this particular application.

I personally would also advice against the shared 10A power supply for the mono blocks. Yes, today you will use them stacked on your desk with the Y-cable, but maybe not in a few years. Better get 5A to make sure they can be used meters apart.

I also don't see the benefit of a 10A power supply for a single V3 mono, as there are no measurements made by "our guys" that show a clear benefit. If there are benefits, they are at the very edge of performance for these chipamps, where i never will run them.

In summary:

• ignore GaN for this application
• 2x 5A is more flexible than 1x 10A
• 5A gives you the performance as it was measured by Amir

April 20th, 15:00 UTC.


Great video, i like the parts jumping around on their PCB

BTW, so far we haven't heard anything about cost. Saving 30% is nice and all, but what are we saving it on?

Thanks for your reply.

Getting the Fosi GaN PSU was a complementary fluke. I ordered their early bird special with the two 5A PSUs, 5A PSUs as tested by Amir will provide more than ample power for my meager needs. I already have two 48V 7.3A 350W PSUs that I may end up using though, I can always repurpose the 5A PSUs for other projects. and given the miniscule price difference between no PSU and their 5A PSUs it was kind of a no brainer for me.

Fun times to be an audio entheusiasts

 

[amper42]

The external power supplies are bigger than the V3 amp module. Crazy!

 

[rgpit]

Fastest overfunded project ever? I got 2 amps with 2 48v/5a psu as I plan to keep them very close to my speakers and run long XLR's. Looking forward to these.

Me too!