Hypex FA 253 Plate Amp Getting Extremely Hot and Turning Off

[Trdat]

I have various Hypex amps, a NC502 and NC252 both in very large metal cases that barely get warm even when played for hours at loud volumes however my FA 253 that sits in a small wooden housing literally turns off with the its automatic mode when it gets warm within hours. The FA 253 is used for centre speaker duties.

I'm baffled why it would get hot, its made for subwoofers and internal housing, while in my case it has small air gaps that should allow for some air to breath. In saying this, the overall compartment is very small, nearly same size as the amp(with the two small breathing outlets top and bottom) like a shoebox size. This overheating only occurs in summer, but my room temperature only increases by a couple degrees Celsius.

Can the amp be faulty in some way?

Or can the wooden shoebox style housing really be the culprit? IF so do i put it in a proper metal case or just make the housing much larger?

 

[Palmspar]

I use FA501, FA502 and FA252 in small mdf housings in my diy subs no problems so far.
Are u sure the vent holes in the amps backplate can breathe?

 

[somebodyelse]

Is the plate vertical (front, sides or back of the box) or horizontal (top of the box)? What temperature is your room when it shuts down?

 

[pma]

however my FA 253 that sits in a small wooden housing literally turns off with the its automatic mode when it gets warm within hours.

Are you wondering that it gets hot in a small wooden housing? Really? Wood is not the best thermal conductor, indeed.

 

[somebodyelse]

Are you wondering that it gets hot in a small wooden housing? Really? Wood is not the best thermal conductor, indeed.

Most of the active speakers the FusionAmps power are also made of wood, so that part isn't unusual - see Ascilab A6B Active and SEAS KingRo4y for example. They follow the mounting orientation instructions, and I haven't seen reports of overheating in the KingRo4y build threads. That's why I asked about mounting and ambient temperature.

 

[Trdat]

I use FA501, FA502 and FA252 in small mdf housings in my diy subs no problems so far.
Are u sure the vent holes in the amps backplate can breathe?

How do I figure that out?

 

[Trdat]

Is the plate vertical (front, sides or back of the box) or horizontal (top of the box)? What temperature is your room when it shuts down?

26 Degrees Celsius. At 28 it shuts down pretty quick within 30 min.

 

[Trdat]

Are you wondering that it gets hot in a small wooden housing? Really? Wood is not the best thermal conductor, indeed.

How then would it breath in a subwoofer or speaker?

 

[DVDdoug]

How then would it breath in a subwoofer or speaker?

The plate, mounted in the speaker's back panel is acting as the heatsink and it should have normal ambient air circulation around it.

Some plate amps have heatsink fins, also on the outside of the speaker cabinet. Maybe this one isn't adequately heatsinked? Or there's simply something wrong with it?

I don't know about that amp but "extremely hot" seems unusual. And it's obviously too hot if it's shutting down! Of course it also depends on how hard you're pushing it.

...Shutting down is a lot better than permanently burning-out dying!

 

[respice finem]

How then would it breath in a subwoofer or speaker?

Subs / speakers are either ventilated by the BR port, or closed back ones may have external rear radiators.

An example of it (class AB but doesn't matter, heat is heat):

https://www.audiosciencereview.com/forum/index.php?attachments/neumann-kh310a-review-rear-panel-input-xlr-active-3-way-monitor-jpg.94737/

 

[raindance]

What's it driving? Could be driving a complex or low impedance load that places it's operating point right on the edge and the 2 degree rise pushes it over that edge.

 

[Palmspar]

How do I figure that out?

It looks like the amp lays flat horizontal?
Then there will be no air convection, best is mounted vertical.

 

[Trdat]

What's it driving? Could be driving a complex or low impedance load that places it's operating point right on the edge and the 2 degree rise pushes it over that edge.

Centre speaker and I know the woofer does drop below 4ohms.

 

[Trdat]

It looks like the amp lays flat horizontal?
Then there will be no air convection, best is mounted vertical.

Can that orientation make that much of a difference? I will try, thanks for the advice.

 

[Trdat]

Subs / speakers are either ventilated by the BR port, or closed back ones may have external rear radiators.

An example of it (class AB but doesn't matter, heat is heat):

https://www.audiosciencereview.com/forum/index.php?attachments/neumann-kh310a-review-rear-panel-input-xlr-active-3-way-monitor-jpg.94737/

From this comment it seems like I do have to put it in a proper metal housing like my other Hypex amps. I did try putting some metal on it to mimic heatsinks to help dissipate heat but it was only 2.5kg weight(dumbell weight) which got extremely hot, I think the weight itself wasn't dissipating the heat due to its cylindrical shape.

But my question is what could go wrong for it to heat up like that or it is unlikely faulty and more a ventilation issue? I am guessing that is the case...

 

[respice finem]

A dumbbell weight (iron) is not really a good radiator, aluminum would be better

Cooling Electronics With Thermal Radiation Heat Transfers

Thermal radiation heat transfers are an important part of the thermal management of certain electronic devices.

resources.system-analysis.cadence.com

You will also need some convection, so a box with holes is better than without.
IIRC, @pma had shown a good solution not long ago.

 

[Trdat]

So I just added drilled holes back, top, bottom and sides and so far it hasn't turned off but it's very hot at 45 degrees Celsius in literally 15 min of it being on.

Now, I don't know if that is considered hot but my NC502 at full crank for 2 hours barely gets warm but of course its in a large metal casing.

Is 45 degrees normal for long periods of time(I say this because its the centre speaker and I want to leave it on permanently) lets say if it doesn't switch off?

 

[somebodyelse]

Can that orientation make that much of a difference? I will try, thanks for the advice.

Yes. They put mounting requirements in the manual for a reason. Same goes for the ventilation holes towards the ends of the plate.

 

[Sokel]

So I just added drilled holes back, top, bottom and sides and so far it hasn't turned off but it's very hot at 45 degrees Celsius in literally 15 min of it being on.

Now, I don't know if that is considered hot but my NC502 at full crank for 2 hours barely gets warm but of course its in a large metal casing.

Is 45 degrees normal for long periods of time(I say this because its the centre speaker and I want to leave it on permanently) lets say if it doesn't switch off?

45° C, where?
At the heatshink? That's nothing for and amp.

The only thing I can think of (apart of the obvious other said above) is that maybe the amp has somehow loosen from its heatshink and the output devices do not convert heat properly. If not faulty in the first place of course.

(what are these thin cables at the back? Signal? you may want to twist them, the way they are is the most no-no there is)

 

[sigbergaudio]