Fosi Audio V3 Mono Amplifier Review

[Fosi Audio]

@Fosi Audio, any plans to offer these as a bare amp board/module down the road?!

Sorry, we currently do not have a plan to offer amp boards or modules of the V3 mono in the short term, but we are indeed looking into this business.

 

[Fosi Audio]

I’m curious if I’ll notice much difference vs. the Class D Pascal amp in my Parasound NewClassic 200 Integrated.

We're looking forward to your sharing of comparing the two setups.

 

[36mbbj]

@Fosi Audio:

Have you considered putting two of these amps into a single, 1U rack-mountable chassis?
One set of switches instead of two, most probably better cooling and if the PSU was in the same chassis, a MUCH tidier setup.

Such an amp could become the next Dynaco ST-70 or, if you want, the next NAD 3020 of power amps (yes, I'm that old).

P.S.: I've just checked your Kickstarter page for this product and I've noticed the "V3 Mono*2 + 48V/10A Power Supply*1" bundle, but I've not seen a proper description of it. I'm assuming there is some special cable to link both amp to the same PSU or are we dealing with a PSU that has two output connectors? Thanks for any explanation you can provide.

P.P.S.: I just needed to scroll further down the product's page to stumble onto the mention of a splitter cable that lets the 48V/10A PSU power two V3 Mono amps.

 

[Fosi Audio]

Have you considered putting two of these amps into a single, 1U rack-mountable chassis?
One set of switches instead of two, most probably better cooling and if the PSU was in the same chassis, a MUCH tidier setup.

It feels like you're on the same wavelength as us! We've recently begun exploring a similar solution – housing multiple amplifier boards within a single chassis and incorporating an internal power supply. Users will have the option to install anywhere from 2 to 5 amplifier boards, somewhat akin to a NAS system supporting multiple hard drives.

I'm assuming there is some special cable to link both amp to the same PSU or are we dealing with a PSU that has two output connectors?

Yes, we'll provide a Y splitter cable for the connection. Probably we'll also provide an external power filter.

 

[Cal_Cobra]

It feels like you're on the same wavelength as us! We've recently begun exploring a similar solution – housing multiple amplifier boards within a single chassis and incorporating an internal power supply. Users will have the option to install anywhere from 2 to 5 amplifier boards, somewhat akin to a NAS system supporting multiple hard drives.

Add BLUE back-lit VU meters and we have a winner

 

[Bleib]

He has some problems with the 48v / 10A powersupply. He recommends having 2 independent instead

Edit: I missed that he has posted a pinned comment, Fosi had already responded to this:
"Hi everyone, regarding my power supply issue, Fosi reached out to me with the following note: "We sent you a 48V/10A power supply along with a power splitter cable. However, as this is from the first batch of products, there is a noise issue when using the 48V/10A power supply with two units. We are currently working on solving this issue, and the officially sold products will not have this problem. Please be aware.""

 

[Guddu]

He has some problems with the 48v / 10A powersupply. He recommends having 2 independent instead

Strange to think how may this be possible that they didn’t find it in their product before sending it to so called youtube influencers.
What happened to internal testing and all!

 

[Bleib]

Strange to think how may this be possible that they didn’t find it in their product before sending it to so called youtube influencers.
What happened to internal testing and all!

I missed the pinned comment:
"Hi everyone, regarding my power supply issue, Fosi reached out to me with the following note: "We sent you a 48V/10A power supply along with a power splitter cable. However, as this is from the first batch of products, there is a noise issue when using the 48V/10A power supply with two units. We are currently working on solving this issue, and the officially sold products will not have this problem. Please be aware.""

 

[LukeA]

It feels like you're on the same wavelength as us! We've recently begun exploring a similar solution – housing multiple amplifier boards within a single chassis and incorporating an internal power supply. Users will have the option to install anywhere from 2 to 5 amplifier boards, somewhat akin to a NAS system supporting multiple hard drives.


Yes, we'll provide a Y splitter cable for the connection. Probably we'll also provide an external power filter.

Do the y-splitter cables come with the 4x amp, 2x power supply backer option or do I have to add them as an extra?

 

[Negatywny]

YT reviews jumped in line with the Kickstarter campaign. They are not particularly interesting, here you have this black box, it has this whimsical thing on the front, and it sounds very nice, subscribe Well, I'm waiting for a review by Andrew Robinson, who has already recorded several rants for Chinese amplifiers, how they are almost a fraud because they have little power - you know, only 50W, and that's almost certainly not enough for everyone! But if you have to review a tube amplifier that has 10W and costs $10k, it can easily provide sound for a 70m2 living room I wonder what this fool will say now.

 

[amix]

We've recently begun exploring a similar solution – housing multiple amplifier boards within a single chassis and incorporating an internal power supply. Users will have the option to install anywhere from 2 to 5 amplifier boards, somewhat akin to a NAS system supporting multiple hard drives.

Very good!

 

[amix]

Add BLUE back-lit VU meters and we have a winner

My SONY cassiever in the eighties would let you set the backlight from green to orange to white to match the cockpit lighting of your car. ;-)

 

[antcollinet]

Strange to think how may this be possible that they didn’t find it in their product before sending it to so called youtube influencers.

When a device is pre production it is because the development is not finished. More often than not the product testing is still ongoing. It would be a surprise if pre production devices didn’t have some issues.

 

[MCH]

He has some problems with the 48v / 10A powersupply. He recommends having 2 independent instead

Edit: I missed that he has posted a pinned comment, Fosi had already responded to this:
"Hi everyone, regarding my power supply issue, Fosi reached out to me with the following note: "We sent you a 48V/10A power supply along with a power splitter cable. However, as this is from the first batch of products, there is a noise issue when using the 48V/10A power supply with two units. We are currently working on solving this issue, and the officially sold products will not have this problem. Please be aware.""

Two out of two reviewers sharing power supply between two amps with a Y cable that have a noise issue. I hope it is not the below or they will have to come with some sort of active splitter. I will be curious to see what solution they come with, maybe some sort of filter to tame the PWM power demand spikes?

The power supply sharing is something interesting to me. Actually, various TPA3255 can be operated in master/slave mode so that they delay the switching between each other, apparently to "minimize noise coupling between audio channels through the power supply." and "Inter-channel delay is needed to optimize audio performance and to get better operating conditions for the power supply" according to the datasheet (below).
Given the fact that most probably two fosi sharing PSU with one of these Y cables are in fact directly connected in between, but not in master/slave mode, i would be curious to understand what this means for the performance of the amps and the power supply.

View attachment 361807

For full disclosure:

View attachment 363206
From here:

https://www.ti.com/lit/pdf/slaa787

I don't see any mention to radio stations whatsoever, only to issues related to power supplies and noise. If you are referring to the choice of a different switching frequency to avoid radio interferences is a completely different thing.

 

[Talisman]

The problem is users who always have something to complain about.
When the za3 came out it was reviewed after a while and there was an avalanche of criticism for not sending the device first to have the review immediately upon release.
Then, to guarantee the review upon release, the company sends the devices still in the development phase (with inevitable problems of youth and parameters that are not yet perfectly definitive) and the same people complain about the review which does not represent the performance of the product launched on the market.
Make peace with your brain.

 

[wric01]

Youtube reviewers say scorching hot after 3 to 4 hours hits 120 degrees, first 1 to 2 hours 100degrees. Good thing my za3 monos are larger box and just warmer all day loads.

 

[Bleib]

Scorching hot after 3 hours hits 120 degrees. Good thing my za3 monos are larger box and just warmer all day loads.

Fahrenheit obviously, and not as hot as many AVRs
Likely the temperature can be lowered quite a bit by raising them up a bit and allowing a bit more air underneath, and as usually not stacking them one on top of the other.

 

[Doodski]

Youtube reviewers say scorching hot after 3 to 4 hours hits 120 degrees, first 1 to 2 hours 100degrees. Good thing my za3 monos are larger box and just warmer all day loads.

100 F or 120 F are both very low 38 C to 49 C temps and for even a lowly domestic grade of ICs they should sustain @ ~85 C. The electrolytic caps are rated for 105 C <?> So far those temps look good if they are done with accurate metering.

 

[Adrian Parker]

@Fosi Audio:

Have you considered putting two of these amps into a single, 1U rack-mountable chassis?
One set of switches instead of two, most probably better cooling and if the PSU was in the same chassis, a MUCH tidier setup.

Such an amp could become the next Dynaco ST-70 or, if you want, the next NAD 3020 of power amps (yes, I'm that old).

P.S.: I've just checked your Kickstarter page for this product and I've noticed the "V3 Mono*2 + 48V/10A Power Supply*1" bundle, but I've not seen a proper description of it. I'm assuming there is some special cable to link both amp to the same PSU or are we dealing with a PSU that has two output connectors? Thanks for any explanation you can provide.

P.P.S.: I just needed to scroll further down the product's page to stumble onto the mention of a splitter cable that lets the 48V/10A PSU power two V3 Mono amps.

Hello @Fosi Audio one YouTube reviewer is saying that there is cross-talk from the single power supply, "pop and crackle" noises - demonstrated in the video. Suggests avoiding the single power supply, as it goes against "conventional wisdom". Is this a known issue, and will it be fixed, or will Fosi give all backers of the single supply a discount code for a second? I am now concerned at a time when I should be excited. Also I am still not sure how I will connect to my Sub? There is not means to do so, right?

 

[Adrian Parker]

Fahrenheit obviously, and not as hot as many AVRs
Likely the temperature can be lowered quite a bit but raising them up a bit and allowing a bit more air underneath, and as usually not stacking them one on top of the other.

My ignorance, probably, but a small fire gives off less heat than a big fire-yes? Do these amps give off less heat in total than a full sized AB 300W/channel AMP? This is the only reason that I am investing. I get too hot in my Shedquarters (new family name for my man cave - where I work) with my current (pun intended) amp.