Fosi Audio V3 Mono Amplifier Review

[DavidM1]

Very cool. Let us know here what it runs like. How is the power output? Is it enough? Are there speaker low impedance issues with the amps, do they run hot with the Magnepans and whatever else you can think up too.

And… is there a pop either when starting from the switch or when starting from auto? Thanks!

 

[Deleted member 72219]

And… is there a pop either when starting from the switch or when starting from auto? Thanks!

Have not experienced any severe pops when the auto start kicks. However, I am pushing mere KEF LS50 Metas.

-Ed

 

[avdoc]

And… is there a pop either when starting from the switch or when starting from auto? Thanks!

I have not heard a pop coming from the speaker, but there is a click from the unit itself after turning it on. I am not using the auto setting as I heard there was a high current draw while it's in standby. Interestingly, on the outside of the box it says there's an 18 month warranty but the manual states 24 months. My understanding after purchase was that it's 2 years, so I'm assuming the 18 month statement on the box is incorrect. As long as there are no issues, I'm planning to do critical A/B testing in my main system tomorrow (Magnepan 2.5R speakers using pre-outs from my Pioneer Elite SC-LX901 receiver). So far, the only comment I can make is that I don't hear anything out of the ordinary, but I prefer the sound of the 25dB gain over the 31dB. To my ears, the 31dB sounds congested and more forward/pushed.

 

[I_L_Music]

A proverb saying goes at my place “The fun that lies in waiting, is not there in seeing”.
I think we should enjoy the waiting period and not put too much pressure on Fosi for shipment. I don’t think they will any benifits in delaying the shipments. In fact, too much pressure from customers may force them to take shortcuts and affect the quality of the product, so it is in our interest to not put too much pressure.

We should enjoy the wait and request other members, who has received the product to keep on sharing the sound impressions. This is what I think..

 

[gazza58]

arrived today with 2x5A
after 2 hours of operation instead of the fosi ZA3
better curtain in width and depth
qobuz bitperfect with pi4 with I2S out card on smsl do300ex as pre-dac
almost excessive power with my Borea BR8
with heat gun max temperature from 49° above, up to 36 below

 

[Chipk]

I am perceiving an improvement with the monoblocks over my Fosi V3. I have a wiim mini->schiit modi dac->fosi amp(s)->
Elac DBR-62. I am just liking the sound better.

Much bigger sound improvement than the orange knob!

 

[Mr_Jman]

I got mine 6 days now .. end i am very happy! compaired to the sabaj a30a they have a wider soundstage, the channel separation is much beter and darker background .. they have more detail and beter imaging then the a30a.

Im not hearing any hiss or poping .. im using it with a smsl d6s usb only with xlr.

 

[Pecottye]

Just got a set V3 mono's with 5A power supply's, twin Muses 02 opamps and t-shirt. I switched my pledge from single 10A power supply to dual mono when the message came out that there would be a extra unit between the power supply and mono's. That switch was registered loose from the kickstarter campain via e-mail and possible the reason that I got mine send quite quickly.
The improvement over a XTZ A2-300 via RCA in my system is significant. Especially with dual Muses 02 opamps per unit. Nice open soundstage, tight bass but less than the XTZ.

System:
Wiim pro - Sanskrit pro panda dac - Home made 5751 tube pre-amp - fosi mono's (31db) => Aliante 10" via wondom DSP Mirage Class D subamp and Ellam XT's with over the top filter (troelsgravesen)

What I do find is that they run quite hot, almost not to touch after a few hours of background playing. Roomtemperature about 25°C.
Besides that, one of my RCA cables had a loose ground and I got a loud popping and hissing threw the whole system when I connected that V3 mono. So, check your cables

 

[Mr_Jman]

What I do find is that they run quite hot, almost not to touch after a few hours of background playing. Roomtemperature about 25°C

on a hot day mine got up to 43°C with a roomtemp of around 31°C and 40°C with roomtemp at 25°C so pretty stable i think nothing to crazy

 

[VTHokie83]

Just received mine as well, 3 V3 Monos with 3 5A PSUs, and a couple of op amps. I know there is some confusion on deliveries, but it's not overly surprising to me.....1900 orders and most were for multiple amplifiers, going from zero to delivering 1000 amps a week or so does not seem out of the norm to me. I won't be able to hook mine up for several weeks, so no input on SQ.....but the build quality seems excellent for such an inexpensive product

 

[Deleted member 72219]

....but the build quality seems excellent for such an inexpensive product

Agreed! Better than ZA3, which cost more yet multiple people I’ve seen had their RCA connectors come clean off. That’s a joke.

-Ed

 

[drmevo]

Mine just arrived out of nowhere! I never received any kind of shipping notification, or any communication at all, directly from Fosi (I did get all of the usual notifications from Kickstarter). So, anyone still waiting might have them show up at your doorstep randomly.

 

[Hot Mason]

How was the experience of purchasing and using it? I would like to purchase two units as well.

 

[Cardone]

Good morning, I tested my 2 mono with 2 5A for 2 hours on Saturday. No pops or other noises to be heard.
Good sound with lots of detail.

 

[Endibol]

Fosi promised me the delivery of 2 units + 10A power supply before the end of June. I just received the message below. As noticed before, they do have a problem with the power filter deliveries. I appreciate it they offer me a choice. I think this is proper communication, nothing to complain so far.

Hi

Thank you for your continued support of our project. Due to some delays, our power filters will not be available for shipping until after the 15th July. We would like to know if you prefer we ship your other items now, or wait and send everything together once the filters are ready. Your feedback is invaluable to us, and we appreciate your patience and understanding as we work to fulfill your order.

Looking forward to hearing back from you soon.

Fosi Audio Team

 

[StereoHz]

Just an update for those eagerly awaitng their amps, or those lacking any further communication from Fosi after the survey/address.
I am backer #173 and mine are in transit. I expect another week to get from Finland to Latvia. Nothing to do but wait.
"Patience, young Padawan".

 

[avdoc]

I'm extremely happy with my 2x V3 monos with 2x 5A power supplies! With the 5A power supplies, I have no turn-on pops through the speakers (I think it may a 10A PS problem). I'm using the V3 monos with RCA pre-outs from my Pioneer Elite SC-LX901 receiver (for those of you unaware, the Pioneer was the premier receiver a few years ago and uses class D ICE amplifiers) into my Magnepan 2.5R speakers using DH Labs silver sonic cabling (RCAs and speaker cables) in an extremely large open concept living area with 20 foot cathedral ceilings. Magnepans are extremely revealing and inefficient 4 ohm speakers which require quality amplification and high current. Regarding sound quality, the Pioneer has a hard edge to the sound which is unpleasant compared to the natural sounding V3s. Also, the sonic background of the V3 monos is completely silent whereas the Pioneer has low level noise. I blind A/B compared the V3 monos vs. the Pioneer with my wife who is not an audiophile and she corroborated my observations (I used an SPL meter to level match the Pioneer). The V3 monos do get hot, but no hotter than my Pioneer. It's not burn-your hand hot, but it's more than just warm. The V3 monos are currently being powered by a 15 amp line on the same circuit as all my other equipment (receiver, TV, blu-ray player, lights), so I'm particularly impressed with their performance on the sub-par electrical connection I currently have available (I'm planning to install a dedicated 20 amp outlet for them soon). Despite the large size of my room and the inefficiency of my Magnepans, the V3 monos are able to drive the speakers to room-filling levels with both music and movies. Regarding the output level of the V3 monos, I am running them at 25dB gain as I liked the sound vs the 31dB. Compared to the Pioneer, I had to turn the volume up 3.5dB to match the output. However, since the sound quality is better I was able to turn the volume down compared to how I normally listen so I'm very happy with the output. I have owned many high-end amplifiers in the past costing many, many times the price of the V3 monos and weighing exponentially more. I'm thrilled that sound like this can come out of such a small, light, and inexpensive component. Once they're available on Amazon, I'm planning to purchase enough to power my 7.2.4 system and a processor with balanced outputs, but given how good the V3 monos sound as is I'm more than content for now.

 

[Kayshot]

Mine just arrived out of nowhere! I never received any kind of shipping notification, or any communication at all, directly from Fosi (I did get all of the usual notifications from Kickstarter). So, anyone still waiting might have them show up at your doorstep randomly.

Did your reward status in Kickstarter change to delivered? Or does it still say "Not Provided"?

 

[Eron]

Just got mine today. Using them with my Lintons. Seems to have better imaging to my ears from the Dual A07 Max's.

Using the lower gain of 25.. Any recommendations on gain use here?

I guess I'll try em both, I more or less heard to only use high gain if you really need the extra volume. Is that so?

 

[Jefesix]

I know there is “debate” about some specifications, if they are really audible. But does anybody seen what is the Damping factor of the FOSI monos?, my intention is to use a couple to power two 8 inch subwoofers.