Amplifier shutting down

[S-fr]

I got this chinese xy-p40w amplifier powered up by 20v after step up and using it for 5.5 ohms speakers the issue is that its truns it self off and back onn when there is bass, what could be the problem if anyone can help

 

[rjenkinsgb]

The boost PSU module is likely nowhere near powerful enough for the amp. It would also need a large reservoir capacitor across the boost module output, to handle current peaks, even at relatively low average power.

What are you using as a power source and at what voltage? The amp info says a minimum of 2A at 20V, so over 40W from the external PSU?

 

[Nigel Goodwin]

Those boost modules are excellent, but I doubt they could feed a 40W amplifier, depending how imaginary the power output might be?. The boost module is 2A MAXIMUM and you're likely to be easily exceeding that on bass peaks.

Also, as rjenkinsgb asked, what supply are you feeding it?, and a large reservoir capacitor is likely to be required.

 

[Tony Stewart]

Consider a Laptop charger. typically 19.5V unless universal selectable, at least 65W ,preferably adjustable.

65W can drive 3.33 Ohms at 19.5V, whereas a 2A 20V boost can only drive 20/2= 10 ohms.
I wonder if boost or 40W is rated for 5.5 ohms but certainly it is an over-current problem.
It could also be your DC input failing from overtemp, whatever that is.

Your next problem will be a hot driver heatsink, then you need a 1U size 24V fan.

 

[S-fr]

The boost PSU module is likely nowhere near powerful enough for the amp. It would also need a large reservoir capacitor across the boost module output, to handle current peaks, even at relatively low average power.

What are you using as a power source and at what voltage? The amp info says a minimum of 2A at 20V, so over 40W from the external PSU?

I got 12v 4a power supply

 

[S-fr]

Those boost modules are excellent, but I doubt they could feed a 40W amplifier, depending how imaginary the power output might be?. The boost module is 2A MAXIMUM and you're likely to be easily exceeding that on bass peaks.

Also, as rjenkinsgb asked, what supply are you feeding it?, and a large reservoir capacitor is likely to be required.

Right now I'm using a 12v 4a supply, and i do have some 6800 uf capacitor ill use em, but does a capacitor reall makes a difference??

 

[S-fr]

Consider a Laptop charger. typically 19.5V unless universal selectable, at least 65W ,preferably adjustable.

65W can drive 3.33 Ohms at 19.5V, whereas a 2A 20V boost can only drive 20/2= 10 ohms.
I wonder if boost or 40W is rated for 5.5 ohms but certainly it is an over-current problem.
It could also be your DC input failing from overtemp, whatever that is.

Your next problem will be a hot driver heatsink, then you need a 1U size 24V fan.

I dont think heating is a real issue, the ic does gets hot but thats much is ig normal, i did tried to find the datasheet for it but i could find any

 

[Nigel Goodwin]

Right now I'm using a 12v 4a supply, and i do have some 6800 uf capacitor ill use em, but does a capacitor reall makes a difference??

Yes, it's the reservoir capacitor that provides high current pulses. You might try one on the power input of the amplifier (after the boost converter), but basically I suspect the boost converter is too small.

 

[S-fr]

Yes, it's the reservoir capacitor that provides high current pulses. You might try one on the power input of the amplifier (after the boost converter), but basically I suspect the boost converter is too small.

I do have a laptop power supply ig thats 19.5v, ill use that if that helps

 

[Tony Stewart]

I said "Your next problem will be a hot driver heatsink, then you need a 1U size 24V fan. "

That is if your Amp starts and stays on under full load.
Then you may want cooling, so the caps don't heat up.

 

[Tony Stewart]

Does a high velocity air fan help at all?

 

[S-fr]

Does a high velocity air fan help at all?

50/50,I mean a fan is a fan, if you want just circulation of air in a container or a box just make some Big wholes in it the air will circulate according to its surrounding environment or just add a small normal DC fan, but if you got something in that container or box thats getting really hot and it shouldn't be, then yeah you need a high velocity fan, for me it depends but i normally use a small one and focus on the airflow direction, confirming the cold air coming in the box is hitting the heat source before exiting.

 

[Tony Stewart]

My experience is PC box Fans are poor at cooling since the CPU heat circulates inside the box when it ought to be ducted to the box interface.

OCP threshold will have a low Rs sense resistor.

 

[S-fr]

My experience is PC box Fans are poor at cooling since the CPU heat circulates inside the box when it ought to be ducted to the box interface.

OCP threshold will have a low Rs sense resistor.
View attachment 144799

Well it depends if its an OEM, it will generally got 2 at best one either for air intake and one for the out., other one at heatsink, they gotta atleast put 3 for a proper airflow and then tbh i dont think either of them needs to be of high velocity fan, if there are 3,

 

[Tony Stewart]

Well it depends if its an OEM, it will generally got 2 at best one either for air intake and one for the out., other one at heatsink, they gotta atleast put 3 for a proper airflow and then tbh i dont think either of them needs to be of high velocity fan, if there are 3,

That design is suboptimal.
CPU fan with high velocity over dense fins produces noise from the sharp interface to the blades then just circulates the heat into the cabinet. The Noise is high and heat rises in the cabinet must then be removed. This can be eliminated with an inline duct fan that is laminar quiet and directly removes heat from the box while drawing in fresh air.

The fact is that hotspot rise is controlled by turbulent air velocity and box thermal control is simply based on volume of air exchanged and the temperature difference.

Yet converting CFM or cubic feet per minute to m/s depends on the blade/motor design and P/V chart from loading effects.

I successfully did a 19" rack-mount design for CMAC supplied to Lucent in a 1U high closed rack with an open frame 185W PSU. I chose a thermal sensor then epoxied to the hottest part, the transformer core to control the speed of dual 1U 1.75" fans to push out air to the side vents, while intake air was channeled with a mylar spoiler. I used a transistor to regulate an LDO to control the speed with the LM317 mounted to the case. It channeled the air in a laminar fashion then near the PSU with a spoiler to setup small eddy current's to force the air to circulate to the PCB and hotspots and prevent the air from just flying over the top., which is the path of least resistance.
This made a 20'C difference to temperature rise to the hotspot and only needed the fan at full power with a 45'C ambient.

 

[audioguru]

The cheap no-name-brand amplifier is missing a heatsink on the amplifier IC so of course it shuts down when playing loudly.
You feel the average IC temperature, not the internal momentary peak temperature.

 

[S-fr]

That design is suboptimal.
CPU fan with high velocity over dense fins produces noise from the sharp interface to the blades then just circulates the heat into the cabinet. The Noise is high and heat rises in the cabinet must then be removed. This can be eliminated with an inline duct fan that is laminar quiet and directly removes heat from the box while drawing in fresh air.

The fact is that hotspot rise is controlled by turbulent air velocity and box thermal control is simply based on volume of air exchanged and the temperature difference.

Yet converting CFM or cubic feet per minute to m/s depends on the blade/motor design and P/V chart from loading effects.

I successfully did a 19" rack-mount design for CMAC supplied to Lucent in a 1U high closed rack with an open frame 185W PSU. I chose a thermal sensor then epoxied to the hottest part, the transformer core to control the speed of dual 1U 1.75" fans to push out air to the side vents, while intake air was channeled with a mylar spoiler. I used a transistor to regulate an LDO to control the speed with the LM317 mounted to the case. It channeled the air in a laminar fashion then near the PSU with a spoiler to setup small eddy current's to force the air to circulate to the PCB and hotspots and prevent the air from just flying over the top., which is the path of least resistance.
This made a 20'C difference to temperature rise to the hotspot and only needed the fan at full power with a 45'C ambient.

That's what im saying, better airflow direction matters,
Then yeah adding measuring the temperature and fan spending according to the temperature is a next step too, but bro 1.75" fan seems a lil too small, im guessing its one of those high Ampere server fans, also adding even a small heatsink to you pcb board would help with great heat control, one more thing lm317 as far as i know is controlled manually with a potentiometer.., made an automatic one with heat measuring?? Cuz like obviously after a certain temperature the fan is at full speed but can you control that speed/temperature?? Are you using an Arduino board for that?

 

[Tony Stewart]

Use any 6W fan, regulate current with a power transistor or use a signal transistor to regulate R ratio on LM317 using simple thermocouple, and transistor on 6W heatsink. Been there, done that.

 

[christinescoms]

That design is suboptimal.
CPU fan with high velocity over dense fins produces noise from the sharp interface to the blades then just circulates the heat into the cabinet. The Noise is high and heat rises in the cabinet must then be removed. This can be eliminated with an inline duct fan that is laminar quiet and directly removes heat from the box while drawing in fresh air.

The fact is that hotspot rise is controlled by turbulent air velocity and box thermal control is simply based on volume of air exchanged and the temperature difference.

Yet converting CFM or cubic feet per minute to m/s depends on the blade/motor design and P/V chart from loading effects.

I successfully did a 19" rack-mount design for CMAC supplied to Lucent in a 1U high closed rack with an open frame 185W PSU. I chose a thermal sensor then epoxied to the hottest part, the transformer core to control the speed of dual 1U 1.75" fans to push out air to the side vents, while intake air was channeled with a mylar spoiler Bothell Deck Building Contractor. I used a transistor to regulate an LDO to control the speed with the LM317 mounted to the case. It channeled the air in a laminar fashion then near the PSU with a spoiler to setup small eddy current's to force the air to circulate to the PCB and hotspots and prevent the air from just flying over the top., which is the path of least resistance.
This made a 20'C difference to temperature rise to the hotspot and only needed the fan at full power with a 45'C ambient.

I just added an Emotiva BasX A3 to my Onkyo TX-RZ730. I really like the results. However, when I crank the volume way up near the max, the amp shuts down and goes into protection mode. I have a pair of Polk R700 towers and a Csi A4 for my center. Any suggestions on his to troubleshoot thus issue, or should I simply return the Emotiva?

 

[Nigel Goodwin]

I just added an Emotiva BasX A3 to my Onkyo TX-RZ730. I really like the results. However, when I crank the volume way up near the max, the amp shuts down and goes into protection mode. I have a pair of Polk R700 towers and a Csi A4 for my center. Any suggestions on his to troubleshoot thus issue, or should I simply return the Emotiva?

Don't crank it up too high then - how on earth can you be in the same room as 600W RMS of audio?. It sounds like you're simply over driving the amplifier?.