Fosi V3 Monoblock

[Gray]

Unfortunately my hearing is very dodgy these days, but I’ll see how it goes!

Mine's far from perfect.
But just the fact that you identified the same general traits as I did on the stereo V3.....that's good enough for me, thanks 👍

 

[Witterings]

in this V3 mono has cured the speaker load dependency issue,

What effect does speaker load dependency have on the listening experience?

 

[Gray]

What effect does speaker load dependency have on the listening experience?

It's said to audibly affect the HF performance, depending on the speaker load.

The specific feedback arrangement in the V3 Monoblocks is supposed to have eliminated the issue 🤔

 

[Gray]

Those considering the V3 Monoblocks might like to know that Swiss company Goldmund has a new mono power amp out.

It is likely to sound better* than the V3....but then it's 1,566 times more expensive at £235,000.

Talk about diminished return 🤪

*Wouldn't a genuinely blind test be interesting? 🤔

 

[Witterings]

*Wouldn't a genuinely blind test be interesting? 🤔

Yes it would .... I've often thought that about comparing streamers as well.

 

[manicm]

The V3 Mono's are not a miracle worker - some reviews have suggested that they don't have the widest soundstage, and in certain circumstances they can run out of steam. They represent excellent value, but such a small box can only do so much.

 

[Gray]

The V3 Mono's are not a miracle worker

Well that's true (as it is of all hi-fi).
As for 'running out of steam', I wouldn't mind betting the V3 Monoblock has more than enough steam for most domestic situations.

That Goldmund Telos 4800 has much less chance of running out of steam of course and maybe it has a wider soundstage.
But it still won't be a miracle worker - and, at the price of a house, most would argue that it should be.

 

[martinus]

The Fosi monoblocks are indeed no miracle workers. For my desk set up they are doing marvelous. Notable is the stereo separation. The sound is fast and punchy. As for running 'running out of steam' there is no question of it. You could make steam with the amps, they become hot. I do cool them with a small fan. On the web side of Fosi they offer a cooling solution. For now I am enjoying the amps every day. For the price, I bought them with a discount, they are great. For what is worth, you can upgrade the amps with other / better op amps.

 

[martinus]

Fosi's heating problem monoblock v3 solved...

 

[Gray]

No doubt the fan does it's cooling job 👍
But, however quiet it may be, it will still be making some noise.

My laptop has had the hard drive swapped for an SSD - to eliminate some noise.
But it's still got a fan - which is why I keep it out of my listening room.

Chances are that people don't hear fans when music's playing - just like you can't hear hiss and low level hum when music is playing.
But, if you can hear it when the music stops....then, like it or not, it's part of your music.

Bottom line for me is that if a fan really was necessary with the V3....it would stop me buying a V3. (OK if the pair were behind the front wall in another room).

 

[martinus]

No doubt the fan does it's cooling job 👍
But, however quiet it may be, it will still be making some noise.

My laptop has had the hard drive swapped for an SSD - to eliminate some noise.
But it's still got a fan - which is why I keep it out of my listening room.

Chances are that people don't hear fans when music's playing - just like you can't hear hiss and low level hum when music is playing.
But, if you can hear it when the music stops....then, like it or not, it's part of your music.

Bottom line for me is that if a fan really was necessary with the V3....it would stop me buying a V3. (OK if the pair were behind the front wall in another room).

The fans has a pwm regulator. At the lowest level there is hardly no noise and the amps are cool. Not bulletproof but for now a fine solution

 

[nopiano]

No doubt the fan does it's cooling job 👍
But, however quiet it may be, it will still be making some noise.

My laptop has had the hard drive swapped for an SSD - to eliminate some noise.
But it's still got a fan - which is why I keep it out of my listening room.

Chances are that people don't hear fans when music's playing - just like you can't hear hiss and low level hum when music is playing.
But, if you can hear it when the music stops....then, like it or not, it's part of your music.

Bottom line for me is that if a fan really was necessary with the V3....it would stop me buying a V3. (OK if the pair were behind the front wall in another room).

I’ve measured mine with a medical thermometer that doubles as a room/item thermometer with a setting option. In our typical 22C ambient room the maximum I’ve measured on the Monos is 39.4C.

They are noticeably warmer than the V3 stereo that I still own, and the ZA3 stereo that I sold on. It’s not entirely clear to me why they run warmer. It might be the casing is better at carrying the heat from the chip. It’s conceivable the chip is being driven harder, but there are no measurements I’ve seen to support that.

A few users, especially in warmer countries have resorted to fans, and Fosi themselves have now made some available. Personally, I think it’s impossible to know if the greater case temperature will affect long-term reliability.

The Auto Off-On setting is a boon, as my preamp effectively controls the Fosi pair without my needing to touch them. They turn off after about 10 minutes with no signal. But - and it’s quite a big but - they seem to consume about ten watts on standby. I’m not sure that even meets EU regs, but I recognise it’s not sold from here, and 0.5watts may not be strictly applicable to auto-sensing devices. The Regs are complex and not my forte.

Most importantly, to my ears they’re a distinct step up in sound quality from the stereo, which was a pleasant surprise. Essentially they seem a bit better all round - cleaner, clearer, larger and more effortless.

Ordered direct from Fosi, and shipped onwards from a UK handler thus avoiding import duties, I paid c £205 for the pair inc two 48volt/5amp power supplies.

 

[nopiano]

A picture:-




I have installed them on an old Quadraspire bamboo turntable platform. This sits on a sheet of leathercloth that protects my Pass Labs power amp.

The balanced connections are Linn Silvers (a silly name for pure copper cables) and the speaker wires are Atlas Hyper 3.5, my usual ones. Best not to say that the RRP of the cables exceed the price of the amps! I did get the Atlas and Linns at less than half price by buying used.

 

[Gray]

Best not to say that the RRP of the cables exceed the price of the amps!

🙂 No, but it certainly highlights the Fosi value.

I've read about the 10 watt standby consumption. It is somewhat surprising - and I wouldn't have thought there'd be any exemption in auto-sensing cases 🤔.
Still, compared to class A, it's nothing (as I know you know!)

 

[nopiano]

🙂 No, but it certainly highlights the Fosi value.

I've read about the 10 watt standby consumption. It is somewhat surprising - and I wouldn't have thought there'd be any exemption in auto-sensing cases 🤔.
Still, compared to class A, it's nothing (as I know you know!)

Yes it is weird, and they measure about 29C in a 21C room, measured early morning after in standby overnight. As you say, not much in the scheme of things.

[My Linn streamer is old school (compared with its successor the Selekt) and draws 20 watts in standby, so the case it always warm. That was according to my smart meter. Recently I found a consumption table from Linn which confirms it. In fact they quote 26-27 watts yet only 30 when operating. Not much point in turning to standby!]