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Fosi Audio V3 Mono Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 9 1.5%
  • 2. Not terrible (postman panther)

    Votes: 18 3.0%
  • 3. Fine (happy panther)

    Votes: 121 20.0%
  • 4. Great (golfing panther)

    Votes: 458 75.6%

  • Total voters
    606
:D I have two splitter cables thanks to Fosi ... But if I understand you correctly, we could junk the DC filter and just have a better splitter cable.
So the problem was with the splitter cable? Thank heavens they sound good despite all this (the V3 monos)!
Try it!, but using the DC filter is what is separating the two paths of power.
Pre feed to one amp, and post feed after DC filter
 

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So anyone here "upgraded" from a WiiM Amp to these Monoblocks? From what Ive seen you get a bit more SNR and about 2db more max volume with the V3 Monos. On the other hand the Wiim Amp got better multitone and better intermodulation and ofc dsp more connections and a sub out.

While 200W on paper sounds great its really not much of difference in total db against the 120W of the Wiim Amp.

Any opinions or experiences?
I did, or rather I have both setups on the same speakers. For my purposes, nearfield listening into 4 ohm speakers with 88db sensitivity, I don't need more than the Wiim amp.

I'll be testing the monoblocks later this week, but I've been using an a0300 which is 165w into 4 ohms. (I don't know what its or the wiim amps input sensitivity is but it's presumably ~2v?)

I can get to 50 (nearfield) on the Wiim amp before it's loud and about 33 with the a0300. I predict it'll be about 25 with the monoblocks assuming diminishing returns as you point out.

My AVR is 125w over 5 channels for a bigger room and it gets loud although those speakers have higher sensitivity.
 
I did, or rather I have both setups on the same speakers. For my purposes, nearfield listening into 4 ohm speakers with 88db sensitivity, I don't need more than the Wiim amp.

I'll be testing the monoblocks later this week, but I've been using an a0300 which is 165w into 4 ohms. (I don't know what its or the wiim amps input sensitivity is but it's presumably ~2v?)

I can get to 50 (nearfield) on the Wiim amp before it's loud and about 33 with the a0300. I predict it'll be about 25 with the monoblocks assuming diminishing returns as you point out.

My AVR is 125w over 5 channels for a bigger room and it gets loud although those speakers have higher sensitivity.


I'm going to edit this and say although 33 with the AO300 was excellent, it turns out to be about the top reliable setting before the AO3000 clips. Not a lot of headroom there.

So yeah, I would probably need more than the Wiim Amp. I'm getting the Fosi monoblocks today. I'll report back
 
I'm currently driving my ELAC DBR62 with a Topping E50 and a Fosi BT20A Pro. I'm curious if switching to 2 Fosi v3 mono would make a significant change. I've never tried mono amps. And according to ASR, the BT20A Pro isn't as good as the v3. Any thoughts will be greatly appreciated.

I'm also unclear about a 2 things with those:
- I read about the reversed phases. Is that still a thing? Would I have to check upon receiving them?
- 1 PSU for 2 mono amps with a splitter, or 2 separate PSUs? Does it even matter?

Thanks
 
I'm currently driving my ELAC DBR62 with a Topping E50 and a Fosi BT20A Pro. I'm curious if switching to 2 Fosi v3 mono would make a significant change. I've never tried mono amps. And according to ASR, the BT20A Pro isn't as good as the v3. Any thoughts will be greatly appreciated.

I'm also unclear about a 2 things with those:
- I read about the reversed phases. Is that still a thing? Would I have to check upon receiving them?
- 1 PSU for 2 mono amps with a splitter, or 2 separate PSUs? Does it even matter?

Thanks
Regarding your 2 things:

  1. The reverse phase should be fixed so long as you verify with the supplier. Even if not, you would not need to worry with a stereo set up.
  2. There will be diverse views regarding the PSU but for me it is a question of how your kit is set up. Do you have power sockets near the speakers to run two power supplies to the amplifiers near the speakers, with short speaker cables, and do you connect with balanced cables to have a long interconnect run from the pre-amp / DAC. If not, and you run a compact desktop system, then the single power supply will be fine, and use up one power socket less.

Regarding making a significant change I don't own a BT20A.
I love my V3 monos. I'm connecting with balanced cables from source, through balanced volume pot to the amps. Your E50 should do a good job controlling the volume, and maybe going balanced with amps close to speakers is worth a go ... but the little BT20A Pro still seems a cracking little amp, and powerful with the 48v supply!

Short answer I suspect you can improve on the BT20A - unless you need the tone controls. For me vs the Aiyima A07 or A08 the V3 monos are much better (for me subjectively). There may be new stereo 3255 amps coming out soon too that might measure superbly - we shall see here I guess. 3e audio seem to have one or two pending. You don't necessarily have to go dual mono, but you might have fun doing so with those ELACs.
 
I'm currently driving my ELAC DBR62 with a Topping E50 and a Fosi BT20A Pro. I'm curious if switching to 2 Fosi v3 mono would make a significant change. I've never tried mono amps. And according to ASR, the BT20A Pro isn't as good as the v3. Any thoughts will be greatly appreciated.

I'm also unclear about a 2 things with those:
- I read about the reversed phases. Is that still a thing? Would I have to check upon receiving them?
- 1 PSU for 2 mono amps with a splitter, or 2 separate PSUs? Does it even matter?

Thanks
I'll give you another view.
Each time you have an urge to "upgrade" amps,DACs,preamps,etc take this money and hide it.Promise yourself you won't use it for thingies.

After doing it sometimes and when enough get nicer speakers.And I mean really nicer,going from a small two-way to a similar one doesn't cut it,next day's feeling will be the same.Go WAY nicer.
That's the only upgrade that worth its money at this hobby.
 
I'll give you another view.
Each time you have an urge to "upgrade" amps,DACs,preamps,etc take this money and hide it.Promise yourself you won't use it for thingies.

After doing it sometimes and when enough get nicer speakers.And I mean really nicer,going from a small two-way to a similar one doesn't cut it,next day's feeling will be the same.Go WAY nicer.
That's the only upgrade that worth its money at this hobby.
Magnepans?

The thing about the V3 monos (for me), is that I can't think of a speaker I could not match them with. There are some great 10 / 20 year old designs out there too (I'm using a pair of Triangles). But the BT20A Pro still seems a cracking little amp for desktop speakers in a desktop system...
 
Magnepans?
Can't tell you.What dictates speakers is first room and then taste if all else are in check.
About amps,I would get what gives me complete peace of mind at all aspects,safety and reliability been first.
But that's me,everyone's mind is different.
 
Can't tell you.What dictates speakers is first room and then taste if all else are in check.
About amps,I would get what gives me complete peace of mind at all aspects,safety and reliability been first.
But that's me,everyone's mind is different.
With these latest Class D's (and for me the 325*'s) they have moved the equation as you point out, towards the speakers.

It is the same with DAC's. The bar is so high now with both DAC's and these amps, that speakers that only a few years ago would have been out of picture are now well and truly in it. So I agree with you on this.
 
Thanks @Sokel & @SMen
Regarding your 2 things:

  1. The reverse phase should be fixed so long as you verify with the supplier. Even if not, you would not need to worry with a stereo set up.
  2. There will be diverse views regarding the PSU but for me it is a question of how your kit is set up. Do you have power sockets near the speakers to run two power supplies to the amplifiers near the speakers, with short speaker cables, and do you connect with balanced cables to have a long interconnect run from the pre-amp / DAC. If not, and you run a compact desktop system, then the single power supply will be fine, and use up one power socket less.

Regarding making a significant change I don't own a BT20A.
I love my V3 monos. I'm connecting with balanced cables from source, through balanced volume pot to the amps. Your E50 should do a good job controlling the volume, and maybe going balanced with amps close to speakers is worth a go ... but the little BT20A Pro still seems a cracking little amp, and powerful with the 48v supply!

Short answer I suspect you can improve on the BT20A - unless you need the tone controls. For me vs the Aiyima A07 or A08 the V3 monos are much better (for me subjectively). There may be new stereo 3255 amps coming out soon too that might measure superbly - we shall see here I guess. 3e audio seem to have one or two pending. You don't necessarily have to go dual mono, but you might have fun doing so with those ELACs.
The BT20A Pro is doing a good job but I never had anything to compare it with. Good point about the tone control, I did lower the bass very slightly to not piss off my neighbours as I live in an apartment. I know, it's a shame, but eh, gotta do what you gotta do. I'll try to bring it back to normal to see if it's really that bad first.


I'll give you another view.
Each time you have an urge to "upgrade" amps,DACs,preamps,etc take this money and hide it.Promise yourself you won't use it for thingies.

After doing it sometimes and when enough get nicer speakers.And I mean really nicer,going from a small two-way to a similar one doesn't cut it,next day's feeling will be the same.Go WAY nicer.
That's the only upgrade that worth its money at this hobby.
I'm still undecided to be honest. I know my setup is good as it is right now, but I like to have a look around from time to time to see if some element is worth upgrading. And I'm also curious to try different things. But that's a valid point, you can't beat an upgrade to way better speakers.
 
Magnepans?

The thing about the V3 monos (for me), is that I can't think of a speaker I could not match them with. There are some great 10 / 20 year old designs out there too (I'm using a pair of Triangles). But the BT20A Pro still seems a cracking little amp for desktop speakers in a desktop system...
I have Maggies, and I have a love/hate relationship with them. The sweet spot is extremely small, it is a pita to position them, they are large and clumsy, but oh, the sound…
My amp is a Jeff Rowland Concentra II which is able to drive them without any problems.

I tried a BT20a Pro as a replacement for the Concentra, and while it performed quite well it was audibly worse than the Concentra.

I also tried the V3 Mono, and imho they are comparable to the Concentra. Their sound is a bit different than the Concentra, but the Concentra is a class A/B so this is to be expected.

But whether the difference between the BT20a Pro and the V3 Mono is audible in your system, is extremely dependent on your loudspeakers.

TLDR; Yes, the V3 Mono are definitely better than the BT20a Pro.

Cheers, Joe
PS: Why am I experimenting with other amps? The Concentra is 20 years old and one of my worries is that it might die one day. And for that day I want a replacement, which for me are the V3 Mono (for an unbeatable price)
PPS: I find it utterly fascinating that with modern DACs and amplifiers the cost for a „first-class“ system has gone down massively. The determining factor today is the cost for the loudspeakers, and I would say (gut feeling), that you should invest 70-90% of your overall budget into them.
 
I have Maggies, and I have a love/hate relationship with them. The sweet spot is extremely small, it is a pita to position them, they are large and clumsy, but oh, the sound…
My amp is a Jeff Rowland Concentra II which is able to drive them without any problems.

I tried a BT20a Pro as a replacement for the Concentra, and while it performed quite well it was audibly worse than the Concentra.

I also tried the V3 Mono, and imho they are comparable to the Concentra. Their sound is a bit different than the Concentra, but the Concentra is a class A/B so this is to be expected.

But whether the difference between the BT20a Pro and the V3 Mono is audible in your system, is extremely dependent on your loudspeakers.

TLDR; Yes, the V3 Mono are definitely better than the BT20a Pro.

Cheers, Joe
PS: Why am I experimenting with other amps? The Concentra is 20 years old and one of my worries is that it might die one day. And for that day I want a replacement, which for me are the V3 Mono (for an unbeatable price)
PPS: I find it utterly fascinating that with modern DACs and amplifiers the cost for a „first-class“ system has gone down massively. The determining factor today is the cost for the loudspeakers, and I would say (gut feeling), that you should invest 70-90% of your overall budget into them.
That is a particularly "on point" post Joe!
I have always been curious about Maggies, and would and could now consider giving them a go... :D
 
That is a particularly "on point" post Joe!
I have always been curious about Maggies, and would and could now consider giving them a go... :D
Is your room,and will be the placement absolute symmetrical?Then yes.
It isn't? Then no.
 
Is your room,and will be the placement absolute symmetrical?Then yes.
It isn't? Then no.
I think the main 'takeaway' for @louwii , following @jbaumann 's and everyone's comments, is quite a constructive one. Would not have to be Magnepans, but he might need different neighborly conditions!
 
I think the main 'takeaway' for @louwii , following @jbaumann 's and everyone's comments, is quite a constructive one. Would not have to be Magnepans, but he might need different neighborly conditions!
My comment was about trying Maggies,that's how they shine.
 
My comment was about trying Maggies,that's how they shine.
Yes ok. I just liked the constructive combination of replies. I would certainly want a particular kind of room before putting in Magnepans!
 
Yes ok. I just liked the constructive combination of replies. I would certainly want a particular kind of room before putting in Magnepans!
They aren't that difficult to place but they need space to breath, in particular you need space behind them positioning them something like 1/3 of the way into the room so a largish and longer rather than squarer room is good. Don't push them right up against the side walls either.
 
Yes.



In terms of op-amps? Probably to leave the factory ones alone.

All of the measurements I've seen from different op-amps in products with sockets have shown sometimes marginal improvement (with doubtful audibilty), sometimes a sh¤tfest of added distortion, but mostly practically zero change. There's absolutely no correlation between performance and price/fancyness of the op-amps, since stability mostly rely on other factors. It's a complete dice throw, unless somebody has taken the time to actually verify the effect of a specific swap with measurements. And considering the data we see in this review, the chance of it being worth the trouble is slim to say the least.
Thanks. You solved my tweaks mania.
 
Anyone got shipping updates? I ordered on Aug. 14th and it says it's being shipped from Aug. 28th. No shipping information yet.
 
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