Fosi Audio V3 Mono Amplifier Review

[Bleib]

I have a Topping E70 would this be a suitable pairing for the Fosi Audio V3 Mono.

As long as this doesn't happen

Topping E70 randomly went to MAX volume..

Not sure what happened but all the sudden the E70 went from -30db or so to 0db. Basically blew out my ears for a few seconds and it was stuck on 0db, I couldn't even lower it. Tried spinning the volume control on the E70 for a few seconds, it was locked at 0db. Afraid to put my windows volume...

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I'd purchase a pre-amp

 

[Nyarlathotep]

I have a Topping E70 would this be a suitable pairing for the Fosi Audio V3 Mono.

I have been using my pair of V3 monos with a E70 Velvet for the past couple months (via XLR cables). Seems to work really well for me, definitely happy with the performance.

I had heard of the concern @Bleib mentioned above. I have not experienced it on either this set or the E70 Velvet at work (connected with a pair of Outlaw 2220's). But always cognizant that this could be a bug in the firmware.

 

[xiedd1234]

thanks， i just bought it on Taobao

 

[LukeA]

Finally received my V3 Mono. Got it powering two 12" subwoofers @ 2ohm. Sounds fantastic.

 

[kingkoolkris]

This review just made me buy the Set of 2xV3s with the 48V/10a (split) power brick for 264$ on their website.
Excited to try them with my ADW Duettas.

 

[kingkoolkris]

Another possibility. Costs a bit more but has balanced outputs and a headphone amp and remote. This, along with a WiiM mini, a $20 Sony blu ray transport and a pair of B&W 601 v3 speakers makes up my entire system… including the v3 monos of course.

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Is there anything comparable with a configurable sub-out? Wouldnt need the headphone amp or Bluetooth.

 

[DavidM1]

Is there anything comparable with a configurable sub-out? Wouldnt need the headphone amp or Bluetooth.

I don’t know of any. There are a lot of good DACs but a sub-out is typically from a preamp.

 

[rvsixer]

Is there anything comparable with a configurable sub-out? Wouldnt need the headphone amp or Bluetooth.

I think the closest you can get to is one of the miniDSP FLEX/SHD lineup. Completely configurable (and multiple) subouts, but also with additional preamp functionality (a plus in my book considering the only other thing you need is the Fosi's).

 

[antcollinet]

I think the closest you can get to is one of the miniDSP FLEX/SHD lineup. Completely configurable and multiple subouts, but also with additional preamp functionality (a plus in my book considering the only other thing you need is the Fosi's).

Perhaps something like this...

Tangent PreAmp II (Black)

Shop for Tangent PreAmp II (Black) Stereo Pre-Amplifier with Richer Sounds for expert advice and Lowest Prices Guaranteed

www.richersounds.com

 

[Lux_ury]

Quick question on the monos'.
Everything is running to spec but turning the unit off on one side creates a low hum to the speaker that's still on. So I've got to switch both off simultaneously?
Also who is running two bricks and are you running two DC filters
Realising I need a single DC extension cable if I was to use the DC filter?
By the way after 1.5hrs it never got above 41.3C on both units at max recording temps centre top. Ambient 22C

 

[Kalium]

Long time lurker finally creating an account making my first post. Never had anything useful to add to the discussions here until now.
Ordered a pair Fosi V3 Mono from Swedish Amazon, paid 2999.99SEK (~€260/$290) for it. Including 2 V3 Mono, 1 10A power supply, and 1 DC filter. Shipping was a little longer than usual, a little over a week. Setup was super easy and straightforward.

I have MiniDSP as streamer/pre-amp and using XLR cables to connect the power amplifiers. Previously I've had a pair of Emotiva UPA-1 monoblocks so I am really happy that this new setup is a lot more compacty and "living room friendly" so to speak. The auto on/off feature has worked flawlessly so far the last couple of days. There is an audibly relay click sound from the amplifiers when they turn on/off but I can't really hear any noise coming from the speakers, just the relays. With no music playing they are very quiet. I have to put my ear within 10cm from the tweeter to hear a faint hissing noise. The tweeter is Morel CAT408 with 89dB/w sensitivity. My old Emotiva amplifiers were not this quiet, they had a faint humming noise that could be heard from the listening position.

Sound wise I can't say much really. I don't have golden ears but I can at least say that they are definitely not any worse than my old Emotiva. However I would guess that the V3 Mono would beat the Emotiva in all measurements except maybe power output. Power output shouldn't really be a problem for me though, 89db/w speakers and a quite small living room and mostly listening at low/moderate sound levels. I am planning a new speaker build with high efficiency compression drivers and 10" PA mid-woofers and for those power output of the V3 Mono will definitely not be an issue.

Thermals... These do run pretty hot, to the point where they are almost a little uncomfortable to touch. Hopefully this will not cause any long term issues.

I also noticed that the gain seems to be lower than on my Emotivas. Previously I achieved a good sound level at around -35db to -40db on my SHD. Now I need to go to around -25db to -35db to reach about the same SPL. Not really a problem, just something I noticed.

So far I'm happy with my purchase. Sold the Emotivas today for 5500SEK, almost twice of what I paid for the V3 Mono. Sound is equally good or better. Background noise is gone now. The new power amplifier setup is like 15-20x smaller than my old one.

 

[Lux_ury]

Just used two 48v power bricks sorted out the Hum and popping when on and off.
That YouTube chap who said to use two bricks was right (Laugh emjoi) No DC filter inline. The auto functionality works flawless on mine no delays signal triggers the relay fine.

 

[Guddu]

 

[rvsixer]

Perhaps something like this...

Tangent PreAmp II (Black)

Shop for Tangent PreAmp II (Black) Stereo Pre-Amplifier with Richer Sounds for expert advice and Lowest Prices Guaranteed

www.richersounds.com

Good find.
I'm not the one who was looking, but looking at the datasheet/user manual specs there are none for the sub out. So I kind of doubt the original requestors configurable subout criteria is met (most lower cost devices I have seen/used simply have a full range mono signal for "sub out"). And like the miniDSP suggestion I had put forth, there's the superfluous preamp section the requestor did not need.

 

[Stoutblock]

So none of the Fosi information releases specify different polarity between SE (RCA) and Balanced (XLR)? So were both originally incorrect and now fixed? Or is one or the other originally incorrect and now corrected? Anyone in possession of the new revised version? Curious if they just reversed the output wires to the speaker terminals? If so, we should be able to assume both SE and Balanced were originally incorrect?

Here is a photo from the Fosi FB group that shows new vs old.

 

[Bleib]

View attachment 386594

Seems they should specify in more detail which are fixed and if it's both XLR and RCA. Serialnumbers usually are a good way as purchase dates will be quickly forgotten by most.

 

[Sokel]

fosi has to urgently make sure that PR has some short of connection and understanding with the engineer guy they have there.
I mean...

When someone doesn't know which is which (as the above),how can people expect to get out of this polarity mess?

 

[antcollinet]

Also who is running two bricks and are you running two DC filters

The filter is only needed if you run two amps from one PSU.

 

[antcollinet]

So were both originally incorrect and now fixed? Or is one or the other originally incorrect and now corrected?

We still don't know. because @Fosi Audio IS CONSISTENTLY FAILING TO PROVIDE CLEAR INFORMATION. (Sorry for shouting, but this is getting ridiculous now.

I simply don't understand why.

My recommendation to anyone thinking about purchasing to hold off until this is rectified.

 

[rvsixer]

Pre purchase decision here:
Between the larger 10A brick AND the filter, I am just not seeing the touted more compact/cleaner installation vs. two of the smaller 5A supplies. Is it just me?

I also just sent their support staff the following polarity question, will not purchase before answered satisfactorily:

I would like to purchase your Fosi Mono V3 amps before the 20% off discount code expires. Please advise on the new Fosi Mono V3 units produced after 8/2/2024 (with polarity fix), that switching between RCA and XLR inputs WILL NOT switch speaker output polarity.

In my specific use case of a 2.1 system with a subwoofer (with built-in plate amp):
1) User has a 2.1 system
2) Right and left main speakers are driven by Fosi Mono V3 amps
3) Subwoofer is driven by its own internal amp
4) User selects RCA input on Fosi Mono V3 amps
5) Fosi Mono V3 amps and subwoofer amp are setup to have correctly matched relative polarity (i.e. no severe dip at crossover frequency etc.)
6) User selects XLR input on Fosi Mono V3 amps
7) Fosi Mono V3 and subwoofer amp CONTINUE to have correctly matched relative polarities (i.e. phase between mains and sub are NOT reversed from Fosi RCA input configuration)