Fosi Audio V3 Mono Amplifier Review

[Rafaille]

That's the only upgrade that worth its money at this hobby.

That and room treatment/DSP

 

[louwii]

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.

 

[jbaumann]

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.

 

[SMen]

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...

 

[Sokel]

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...

Is your room,and will be the placement absolute symmetrical?Then yes.
It isn't? Then no.

 

[SMen]

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!

 

[Sokel]

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.

 

[SMen]

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!

 

[gwing]

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.

 

[Pulkass]

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.

 

[kingkoolkris]

Anyone got shipping updates? I ordered on Aug. 14th and it says it's being shipped from Aug. 28th. No shipping information yet.

 

[louwii]

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!

That's actually my plan. I will only upgrade my speakers once I move into a more suited environment, where I could enjoy them with peace of mind. Which might never happen given the real estate market.
That's also why I'm looking at a few upgrades I could do without blowing the bank. I'm also looking into getting some room correction going, which is probably the best choice, before getting new amp(s).

 

[SMen]

That's actually my plan. I will only upgrade my speakers once I move into a more suited environment, where I could enjoy them with peace of mind. Which might never happen given the real estate market.
That's also why I'm looking at a few upgrades I could do without blowing the bank. I'm also looking into getting some room correction going, which is probably the best choice, before getting new amp(s).

Maybe this the way to go: One of these Wiim's also has a 3255 amp module.

Optimizing Your Audio Experience: The Power of Room Correction & How to Use in the WiiM Home App (Updated - Available now for both Android and iOS users)

Enhance your sound system with room correction: adjust audio to your room's acoustics for clearer, accurate, and immersive listening.

www.blog.wiimhome.com

WiiM Amp Streaming Amplifier Review

This is a review and detailed measurements of the WiiM Amp streaming amplifier. It was sent to me by the company and costs US $299. I was pleasantly surprised by the good bit of weight this small box has. It will help it not slide with the weight of the speaker wires and such. Back panel shows...

www.audiosciencereview.com

 

[Mort]

I got my Fosi monoblocks yesterday and they are a bigger upgrade in power than I expected. I'm not sure why but naturally I'm happy.

Before I was using an AO300 from a Wiim Ultra on 2V as a pre amp. With the AO300 fully opened up to 60 (the top volume on the AO300) the AO300 would clip when the Wiim went over 35 (0-100). Over that 35blevel the AO300 would just shut off, presumably overloaded.

With the Fosi i can get the Wiim well over 60 and into volume territory where there is obvious distortion. I don't know if it would go to 100 (full 2 volts) but I got it over 75 and although it didn't sound good at that high a volume (distortion), the Fosi never shut off like the ao300.

I'm powering Philharmonic audio ceramic minis, large 4ohm bookshelf speakers that are not particularly hard to drive.

I'm not surprised the Fosi is better but I'm surprised by how much. Rated power is 165w for the AO300 and 240w for the Fosi. A 50% increase in power shouldn't more than double the output.

Of course I'm not the best at understanding audio engineering. I'm probably misunderstanding something. Why would the Fosi handle so much more?

 

[Deleted member 72219]

I got my Fosi monoblocks yesterday and they are a bigger upgrade in power than I expected. I'm not sure why but naturally I'm happy.

Before I was using an AO300 from a Wiim Ultra on 2V as a pre amp. With the AO300 fully opened up to 60 (the top volume on the AO300) the AO300 would clip when the Wiim went over 35 (0-100). Over that 35blevel the AO300 would just shut off, presumably overloaded.

With the Fosi i can get the Wiim well over 60 and into volume territory where there is obvious distortion. I don't know if it would go to 100 (full 2 volts) but I got it over 75 and although it didn't sound good at that high a volume (distortion), the Fosi never shut off like the ao300.

I'm powering Philharmonic audio ceramic minis, large 4ohm bookshelf speakers that are not particularly hard to drive.

I'm not surprised the Fosi is better but I'm surprised by how much. Rated power is 165w for the AO300 and 240w for the Fosi. A 50% increase in power shouldn't more than double the output.

Of course I'm not the best at understanding audio engineering. I'm probably misunderstanding something. Why would the Fosi handle so much more?

Power is not the only dictator of volume level. Gain is a separate specification. You can amplify with zero gain (unity gain). Your old amplifier and the V3 Monos have different gain based on what you’re saying. Gain is how much volume is increased, and power determines the amplifier’s ability to actually push attached speakers to the volume level you’re asking for. Sort of somewhat like torque versus horsepower.

-Ed

 

[Mort]

Power is not the only dictator of volume level. Gain is a separate specification. You can amplify with zero gain (unity gain). Your old amplifier and the V3 Monos have different gain based on what you’re saying. Gain is how much volume is increased, and power determines the amplifier’s ability to actually push attached speakers to the volume level you’re asking for. Sort of somewhat like torque versus horsepower.

-Ed

I can't find the gain numbers for the ao300 but this is probably it, yeah.

 

[harrym13]

Hi all, new user of this forum here. I've got a few Qs on the V3 monos:

I ordered direct from Fosi ($260 for the pair with the 10a supply) on 7th September. Anyone have any ideas when they might arrive? Shipping to the UK.

I'm planning on using both the RCA and XLR inputs (for two different sources) - RCA being driven from the preouts on my Arcam AVR360 (quite curious to see how the v3 monos compare to a reasonably high end AVR which claims 90wpc...). This will cover Film, TV and streamed music use through the AVR. How do people find the manual switches on the front? Robust? Any audible pops or clicks when switching? Should I worry about the RCA noise issue with the single 10a supply? How do people find the auto power switching? Is it useful/works as intended?

For the XLR inputs, I plan to run directly from my Pioneer XDJ-XZ mixer (I DJ as a hobby). Anyone got any experience running directly from a DJ mixer/controller into these monoblocks? I'm hoping I can run them quite loud without pushing the gain on the mixer too hard... As friends (and me!) DJing have a tendency to push towards the red when a party is rocking and they want a bit more oomph from the speakers...

One of the main reasons I ordered these monoblocks is I fairly regualry take my home audio setup (speakers are Tannoy Revolution XT8F - absolutely adore them, 91dB sensitivity and rated power handling up to 200w) and my DJ decks out to parties - but lugging the 16kg Arcam AVR is an extra pain (along with the heavy speakers and decks)... Plus the Arcam has cut out a couple of times due to thermal protection kicking in. So I'm hoping these little monoblocks paired with my Tannoys will provide suitable levels of reliable power to rock a party for extended periods of time. I considered spending similar money on a pro PA power amp for more power output, but the small class D format of the V3 monos appealed for being very portable and living room suitable (I.e. Not ugly and full of cooling fans!)

If anyone else has any experience using these V3 monos driving similar sensitivity 8ohm speakers fairly loudly for extended periods of time, I'd be keen to hear about it!

Cheers all and thanks for providing hours of reading on these forums!

 

[AudioSceptic]

Thanks for the review. Nice results. And a good price indeed.
Now I am waiting for the stereo version.

2 mono ones are small enough!

 

[Deleted member 72219]

Hi all, new user of this forum here. I've got a few Qs on the V3 monos:

I ordered direct from Fosi ($260 for the pair with the 10a supply) on 7th September. Anyone have any ideas when they might arrive? Shipping to the UK.

I'm planning on using both the RCA and XLR inputs (for two different sources) - RCA being driven from the preouts on my Arcam AVR360 (quite curious to see how the v3 monos compare to a reasonably high end AVR which claims 90wpc...). This will cover Film, TV and streamed music use through the AVR. How do people find the manual switches on the front? Robust? Any audible pops or clicks when switching? Should I worry about the RCA noise issue with the single 10a supply? How do people find the auto power switching? Is it useful/works as intended?

For the XLR inputs, I plan to run directly from my Pioneer XDJ-XZ mixer (I DJ as a hobby). Anyone got any experience running directly from a DJ mixer/controller into these monoblocks? I'm hoping I can run them quite loud without pushing the gain on the mixer too hard... As friends (and me!) DJing have a tendency to push towards the red when a party is rocking and they want a bit more oomph from the speakers...

One of the main reasons I ordered these monoblocks is I fairly regualry take my home audio setup (speakers are Tannoy Revolution XT8F - absolutely adore them, 91dB sensitivity and rated power handling up to 200w) and my DJ decks out to parties - but lugging the 16kg Arcam AVR is an extra pain (along with the heavy speakers and decks)... Plus the Arcam has cut out a couple of times due to thermal protection kicking in. So I'm hoping these little monoblocks paired with my Tannoys will provide suitable levels of reliable power to rock a party for extended periods of time. I considered spending similar money on a pro PA power amp for more power output, but the small class D format of the V3 monos appealed for being very portable and living room suitable (I.e. Not ugly and full of cooling fans!)

If anyone else has any experience using these V3 monos driving similar sensitivity 8ohm speakers fairly loudly for extended periods of time, I'd be keen to hear about it!

Cheers all and thanks for providing hours of reading on these forums!

I don’t recommend changing inputs while powered up—turn it off to switch inputs.

XLR input gain is the lowest, +20dB, compared to the two RCA options.

-Ed

 

[SMen]

Hi all, new user of this forum here. I've got a few Qs on the V3 monos:

I ordered direct from Fosi ($260 for the pair with the 10a supply) on 7th September. Anyone have any ideas when they might arrive? Shipping to the UK.

I'm planning on using both the RCA and XLR inputs (for two different sources) - RCA being driven from the preouts on my Arcam AVR360 (quite curious to see how the v3 monos compare to a reasonably high end AVR which claims 90wpc...). This will cover Film, TV and streamed music use through the AVR. How do people find the manual switches on the front? Robust? Any audible pops or clicks when switching? Should I worry about the RCA noise issue with the single 10a supply? How do people find the auto power switching? Is it useful/works as intended?

For the XLR inputs, I plan to run directly from my Pioneer XDJ-XZ mixer (I DJ as a hobby). Anyone got any experience running directly from a DJ mixer/controller into these monoblocks? I'm hoping I can run them quite loud without pushing the gain on the mixer too hard... As friends (and me!) DJing have a tendency to push towards the red when a party is rocking and they want a bit more oomph from the speakers...

One of the main reasons I ordered these monoblocks is I fairly regualry take my home audio setup (speakers are Tannoy Revolution XT8F - absolutely adore them, 91dB sensitivity and rated power handling up to 200w) and my DJ decks out to parties - but lugging the 16kg Arcam AVR is an extra pain (along with the heavy speakers and decks)... Plus the Arcam has cut out a couple of times due to thermal protection kicking in. So I'm hoping these little monoblocks paired with my Tannoys will provide suitable levels of reliable power to rock a party for extended periods of time. I considered spending similar money on a pro PA power amp for more power output, but the small class D format of the V3 monos appealed for being very portable and living room suitable (I.e. Not ugly and full of cooling fans!)

If anyone else has any experience using these V3 monos driving similar sensitivity 8ohm speakers fairly loudly for extended periods of time, I'd be keen to hear about it!

Cheers all and thanks for providing hours of reading on these forums!

Just a few of your questions:
I'm using 91 db Triangle speakers, 8ohm - the V3 monos are not 'forward' in anyway so this will depend on your mixer.

Balanced inputs going to full volume will depend very much on the maximum output of your mixer - whatever that is on full - I think 4v is enough balanced - both my balanced sources are 5v.

They will certainly go loud ... but partying "punch" ... I'm afraid you will have to report back on that one!

The manual switches are robust enough - feel good as expected - I don't mind the small clicking sound when the amps click on from standby. This feature works very effectively for me. As far as I know having both amps plugged in and on at the same time should be fine with the 10A. You will need decent lengths xlr I'd imagine and short speaker cables to tuck these monos in behind those Tannoys .... so no one steps on them while dancing or whatever!

You should have tracking with your order - mine took about a week from Fosi.

I think these are probably more 'hi fi' than you expect!