Fosi Audio V3 Mono Amplifier Review

[Deleted member 72219]

Let's not go that way. All potential obstacles to lower temperature have been eliminated. The amplifiers are not stacked, they have enough space around them

What speakers are you driving? Are they tough to drive?

-Ed

 

[Basilderat]

Let's not go that way. All potential obstacles to lower temperature have been eliminated. The amplifiers are not stacked, they have enough space around them

I can drive mine pretty hard for three or four hours, then place my hand on top of them immediately after shutdown and they are hot, but not alarmingly so. Not "I have to do something about this hot", and I can leave my hand on top of them no problem. They are noticeably hotter than my Topping PA7 amp driven for the same period at the same levels, but not by a huge margin.

 

[DavidM1]

I realize that locations and people's preferences vary, but those numbers are way too high for room temperature, especially if you're going to have electronics in there.

Whoah! I’m guessing this post is from someone who heats and cools their house a lot. 26C is not at all uncommon in most of Australia nor in Shenzhen where Fosi is based. I still don’t understand the fuss about amplifiers being quite warm to touch. It is to be expected, especially because the case is the heat sink.

 

[renoxd]

What speakers are you driving? Are they tough to drive?

-Ed

Heco Aurora 700 92 dB.

In standby mode they reach around 37. Turned ON but disconnected from speakers around 45 and when playing over 50

 

[Bleib]

Received my 2 units. Both are fixed, one of the units had a bit too little thermal paste so I changed both to the latest from Arctic (Cooling)

 

[antcollinet]

Let's not go that way. All potential obstacles to lower temperature have been eliminated. The amplifiers are not stacked, they have enough space around them

But your room is 5C warmer than typical. It is therefore normal that your amps are getting at least 5c warmer than others.

 

[Lux_ury]

But your room is 5C warmer than typical. It is therefore normal that your amps are getting at least 5c warmer than others.

That's what I was explaining that my ambient is 22C his is 26C which means 4C to 5C more than everyone else.
One thought I don't know what flat screen you have Renoxd, but heat from that could be affecting the readings?
But I'm doing what I said to deal with summer heat. I haven't tested the lower temps yet.

 

[renoxd]

But your room is 5C warmer than typical. It is therefore normal that your amps are getting at least 5c warmer than others.

I certainly don't have a vast knowledge of heat conduction, but I don't think that a room temperature difference between 22- 26C translate into same figure for the device when working at much higher temperature than ambient.

In addition, there are some people whose temperature barely reaches 41 degrees under load, and they don't have 19C in the room. Looking at the fact that my speakers are sensitive, and I don't listen music loud, I still believe that Over 50C is not right. 45C only when turned ON without any load is also not great.

I just got info from Fosi Team to check it with different power supply and socket "as an unstable power voltage may also contribute to these temperature differences". Well, I would, but I don't have any… at least not yet.

 

[Audiotone]

Guess I just won a pair...only had to like Audiophonics/Fosi Audio on Facebook...

Hello,
Congratulations, you have indeed won a pair of Fosi Audio V3 Mono amplifiers!

Next, we just need a postal address, a full name, and a phone number so that Fosi Audio can send your prize

 

[renoxd]

Congrats

 

[r3uba6HBHa2Ye7F]

I know it's class d but did it get hot playing music with lots of bass or Rick music? Thanks

 

[Killingbeans]

Astley or Rubin?

 

[MCH]

I certainly don't have a vast knowledge of heat conduction, but I don't think that a room temperature difference between 22- 26C translate into same figure for the device when working at much higher temperature than ambient.

within such small ranges, it certainly does, roughly.

 

[Lux_ury]

Ok after 4 hours of non stop playing I recorded a temperature of 41C when I first powered it up.
The second picture is the maximum temperature of 35.5C
Ambient 22.C-22.5C
lower temp of 5.5C after the passive radiator and thermal pad costing me U$6.00 dollars per 1C drop (Laugh emoji)

 

[antcollinet]

I certainly don't have a vast knowledge of heat conduction, but I don't think that a room temperature difference between 22- 26C translate into same figure for the device when working at much higher temperature than ambient.

It certainly does.

When you dump power into the enclosure of any device, that power (in the form of heat), must dissipate to the environment (room temperature air). It does this through the thermal resistance of the device to air interface.

This is the same for heatsinks, (or any device trying to get heat out of it into the air) Their key -performance specification is thermal resistance to air rated as degrees C per watt. That means the heatsink temperature is (Thermal resistance) X (power) above the heatsink ambient air temperature. This means that as the ambient temperature rises, so does the surface temperature of the heatsink/device - by the same amount - assuming power is constant.

 

[kelesh]

Whoah! I’m guessing this post is from someone who heats and cools their house a lot. 26C is not at all uncommon in most of Australia nor in Shenzhen where Fosi is based. I still don’t understand the fuss about amplifiers being quite warm to touch. It is to be expected, especially because the case is the heat sink.

"The American Heritage Dictionary of the English Language identifies room temperature as around 20–22 °C (68–72 °F),[1] while the Oxford English Dictionary states that it is "conventionally taken as about 20 °C (68 °F)".[2]"

That's a general consensus, from Wiki. I generally aim for 72-74 °F but, like I said, preferences vary. The point is that, these variations can and do affect the equipment temperature, and vice versa. If I turn on a just a few computers, my room temperature can rise by a few degrees. Class A amps, well, they are like heaters! So I don't think there is anything wrong with the OP's amps, it's all just physics (heat transfer).

 

[gwing]

"The American Heritage Dictionary of the English Language identifies room temperature as around 20–22 °C (68–72 °F),[1] while the Oxford English Dictionary states that it is "conventionally taken as about 20 °C (68 °F)".[2]"

That's a general consensus, from Wiki. I generally aim for 72-74 °F but, like I said, preferences vary. The point is that, these variations can and do affect the equipment temperature, and vice versa. If I turn on a just a few computers, my room temperature can rise by a few degrees. Class A amps, well, they are like heaters! So I don't think there is anything wrong with the OP's amps, it's all just physics (heat transfer).

The issue isn't really how much the amps heat up the room, that might an issue when playing my big class A valve amps in the summer but for any normal amp and in particular these little class D amps you can effectively ignore any contribution they make to room heating. Neither does the heat the case itself reaches matter unless it is dangerously hot to the touch.

The real heat issue is instead how hot the components inside the case get and how much that shortens their life. They are going to be mostly running at a higher temperature than the case itself and so need to be specified accordingly, or to have more effective cooling provided for them

 

[kelesh]

The real heat issue is instead how hot the components inside the case get and how much that shortens their life. They are going to be mostly running at a higher temperature than the case itself and so need to be specified accordingly, or to have more effective cooling provided for them

Longevity is always a valid point, hopefully Fosi have done their homework on this. More effective cooling would mean either a bigger heatsink/case for passive or forced air (fan) for active; and it is specifically the lack of these that's part of the appeal of these little amps IMO, so let's hope they last as they are. Owners are, of course, free to modify at will if they feel something needs to be added or changed. That said, I think I may have some peltiers lying around from the PC overclocking days ...

 

[A.wayne]

Its a Hot deal , The price sounds about right ....

 

[Nopiano]

Ok after 4 hours of non stop playing I recorded a temperature of 41C when I first powered it up.
The second picture is the maximum temperature of 35.5C
Ambient 22.C-22.5C
lower temp of 5.5C after the passive radiator and thermal pad costing me U$6.00 dollars per 1C drop (Laugh emoji)

Very similar findings here. Our room is usually between 20 and 22C ambient and I’ve checked the amps each day since last weekend when I first started using them. My highest reading is 39.1C.

I’m using a medical thermometer that has an object setting too. You can see a little kettle symbol in the window.

As much space as I can give the Monos, they are on an old Quadraspire bamboo turntable platform, and that’s sitting on my Pass Labs XA25 protected from inadvertent scratches by a rectangle of leather-cloth.