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Fosi Audio V3 Mono Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 13 1.8%
  • 2. Not terrible (postman panther)

    Votes: 23 3.2%
  • 3. Fine (happy panther)

    Votes: 139 19.4%
  • 4. Great (golfing panther)

    Votes: 540 75.5%

  • Total voters
    715
i dont have any balanced cables, so i cant try for myself.
if there is no benefit i will leave as it is
There are users of V3 monos who, for various reasons want to run long interconnect cables. That would be another reason you might find people using balanced cables for that particular use case (but this is not yours). They sound great, and I still can't quite get my head around the power vs size of these class D's. Fit beautifully under my tv.
 
New DC filter works.
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I'm a novice but super happy with the mono's. If cooling is a concern you can check out my solution using some AC infinity fans and temp controller. Stays happily with the 28C range.
 

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I'm a novice but super happy with the mono's. If cooling is a concern you can check out my solution using some AC infinity fans and temp controller. Stays happily with the 28C range.
looks neat.

i did not know there was a heat range , do they need to stay under 28c? that doesnt seem very hot.

i may just buy some slightly taller feet for mine, if i get any issues. (not the stupidly expensive snake oil type, i hasten to add ;))
 
There are users of V3 monos who, for various reasons want to run long interconnect cables. That would be another reason you might find people using balanced cables for that particular use case (but this is not yours). They sound great, and I still can't quite get my head around the power vs size of these class D's. Fit beautifully under my tv.
The way my room is set up I have 25’ cable runs to the speakers which I prefer to cover with balanced interconnects and a V3 at each speaker. Hum is also noticeably lower when I keep everything balanced.
Very much enjoying my V3s, such a bargain.
 
is this likely to improve anything?
Well the old one was defective and cross fed feedback noise, plus my work around was to run either two psu bricks(be inefficient), or split the old AC filter so it was filtering only just one power path.(not balanced)
So yes unless you want to run two PSUs or have only one speaker filtered then sure it's a moot point. They listened when I suggested they simply separate the feeds which they took a year to remanufacture, but credit due they supplied one for me with some serious reminders of a conversation I had a year ago with them.
 
Looking at getting one of these to power my car sub in my house. Was running off an old car amp that did 4ohm 200w, (although it was running at 1ohm, and has now died). Anyone know if this amp would handle 1ohm? Worst case i can wire my sub to 4ohms and hopefully get 250W from it?
 
^^^^^I wouldn't do that as that's asking a lot from the V3's; pushing them hard into a 4 ohm or less load. If you do decide to do it a small fan would be a good idea.
Fwiw I've also tried using car subs in the house many years ago and the results were not good. Your mileage may vary but I was not a fan of the number plate rattling one note bass they're designed to produce.
 
^^^^^I wouldn't do that as that's asking a lot from the V3's; pushing them hard into a 4 ohm or less load. If you do decide to do it a small fan would be a good idea.
Fwiw I've also tried using car subs in the house many years ago and the results were not good. Your mileage may vary but I was not a fan of the number plate rattling one note bass they're designed to produce.
I've been using the sub for a while with an amp that died and it's good with DSP in my room. It's a small sealed sub rather than the standard car ported ones. So that's not really an issue for me. I will probably eventually make a new enclosure tailored to the TS specs of the driver.

In terms of the fosi, I see that the tpa3255 is rated to 1.7ohm minimum. So I will probably have to run it at 4ohms. I am not opposed to 3d printing an adapter and sticking a pc fan on it if cooling is an issue.

I'm not sure what else I could use to power it. The other option is to get another car amp, but they go for similar prices to the fosi so I thought this would be a more elegant way of handling it.

Any suggestions for any other good subwoofer amps that aren't too expensive and will be good to drive this sub? I'm not against a small amp powerful amp board and making my own enclosure with cooling etc.
 
A car sub works with the "pressure chamber effect" of the small room of a car. You get with this about +15dB at 30Hz. But not at home so you have to EQ a lot and that needs lots of power from the amp.
Better take a real sub for homeuse.
1Ohm is overkill for V3. I use several at 2 Ohms without probs.
 
A car sub works with the "pressure chamber effect" of the small room of a car. You get with this about +15dB at 30Hz. But not at home so you have to EQ a lot and that needs lots of power from the amp.
Better take a real sub for homeuse.
1Ohm is overkill for V3. I use several at 2 Ohms without probs.
It depends on the specific driver and the enclosure design. In my case with this driver it is sufficient, as I am also using it in a small room at a desk for near field rather than a big home theater room etc.

Good to know that the V3 can do 2ohm stable, I will keep it in mind for my next builds. I may get one and try it at 4ohms with my car sub and see if it has enough power. If not then I will probably have to get a car amp or something like a irs2092 chip amp from wondom. I would also consider the behringer nx3000, however they are quite big for my small room.
 
Soundstream REF 800.4 is a four channel car amp. It is 2Ohm stable in bridge mode so you can make your sub 2x2Ohm and bridge the four amp channels. You get 2x +650W. Sometimes you get them very cheap on eb..
 
I'm not sure what else I could use to power it. The other option is to get another car amp, but they go for similar prices to the fosi so I thought this would be a more elegant way of handling it.
If it was my situation I'd be looking for a pro amp.......... behringer, qsc, crown etc. which are designed to run low impedance loads continuously. Yes the Fosi may be capable of running a 2 ohm load but for how long. Mine get rather warm with a 4 ohm load and no doubt they could fry an egg with a 2ohm car subwoofer load.
 
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Soundstream REF 800.4 is a four channel car amp. It is 2Ohm stable in bridge mode so you can make your sub 2x2Ohm and bridge the four amp channels. You get 2x +650W. Sometimes you get them very cheap on eb..
Can't find them for cheap here in the UK. There are some other car amps new for a similar price to the fosi that can do 1ohm and around 800w RMS.
If it was my situation I'd be looking for a pro amp.......... behringer, qsc, crown etc. which are designed to run low impedance loads continuously. Yes the Fosi may be capable of running a 2 ohm load but for how long. Mine get rather warm with a 4 ohm load and no doubt they could fry an egg with a 2ohm car subwoofer load.
If i was using the Fosi i would for sure run it with a 120mm PC fan strapped to it. I was thinking of the behringer nx3000 as its a similar price, but it is quite big and im wondering if i really need that kind of power.
 
Obviously, not all car audio subwoofers are the same. There are many models that are just as capable, if not more, of working perfectly in a home than dedicated subwoofers.

I have two Coral XL10 subwoofers (Peerless XL10s manufactured for Coral Electronics) that give me spectacular results.

I amplify one of the XL10s (4 ohms) with a ZA3 in mono, and I don't have any problems with it overheating. After hours of use, it's practically at room temperature.
 
Is it copacetic to feed four Fosi V3 mono amps from a single WiiM Pro Plus using an RCA splitter? For a backyard zone with four Def Tech speakers that are rated as "4-8 Ohms", the Fosi Mono's seem like a good solution, but I want to treat it as one zone. Would the split RCA need to be boosted? The other option is 2 WiiM Pro Pluses but I'd like to avoid the extra expense.
 
The WiiM Pro Plus analog RCA outputs have a max 2V rms output voltage with an output impedance of 10 ohms. The current (amps) drawn by the RCA outputs will depend on the impedance of the connected device. So the question is whether the Fosi amps can draw optimal amounts of current from a split RCA output.

The V3 Mono offers two gain settings for the RCA inputs: +25dB and +31dB. This allows for flexibility in matching the amplifier to different source devices.
Impedance: The input impedance for the RCA inputs is 5kΩ.

I've seen measurements where changes in input voltage make a significant difference in performance of an amplifier, and I'm not sure if that is relevant here. Also it generally seems like the split signal would be weaker, so I'm not sure if it still meets the requirements of the amp.
 
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Dzień dobry, w każdym razie Hypex lub Purifi będą miały wyższą moc wyjściową, zarówno pod względem mocy, jak i dynamiki. Piszę ten tekst mając zarówno : Purifi>Focal 926 (91,5db podane przez producenta, ale 88db zmierzone na audio.com.pl) oraz 2x Fosi V3 mono/48V-10A/ELAC DBR62. Pytanie brzmi, czy różnica jest warta dodatkowych
It would be nice if you could write in English
 
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