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Topping PA5 II running hot on idle

cptsantos

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Mar 21, 2024
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Hi guys,

I just bought a Topping PA5 II and have been testing it for the last 3 days. I’m surprised to find it runs very hot even on idle and even at zero knob volume. Weren’t this class D amplifiers supposed to be very energy efficient? The PA5 runs hotter on idle than my Sonos Connect Amp (ZP120) playing at high volume.

Is this normal? I’m thinking about sending it back just because I think at this temperature it will not last long. Is anyone also experiencing this?
 
I have the same problem when using PA5 II with Polk TSi200 Bookshelf (8 ohms). But it is only warm when using it with ELAC Uni-Fi UB5 (4 ohms).
 
@cptsantos Where did you buy from?

@kunkurus from the things you write you seem to have a problem of hight temperature on idle with both Polk AND Elacs!?
 
Hi guys,

I just bought a Topping PA5 II and have been testing it for the last 3 days. I’m surprised to find it runs very hot even on idle and even at zero knob volume. Weren’t this class D amplifiers supposed to be very energy efficient? The PA5 runs hotter on idle than my Sonos Connect Amp (ZP120) playing at high volume.

Is this normal? I’m thinking about sending it back just because I think at this temperature it will not last long. Is anyone also experiencing this?
What exactly does “hot” mean?
Without specifying the temperature, it can be anything from 30° - 70°.
By the way, amplifiers require a basic temperature for a stable operating point.
 
With the Elacs I just measured 36 degrees Celsius at idle (23 degrees ambient temp). I have no measurement for the Polks, but I'm pretty sure it was more than 40.
 
What exactly does “hot” mean?
Without specifying the temperature, it can be anything from 30° - 70°.
By the way, amplifiers require a basic temperature for a stable operating point.
Hot means very warm to the touch. It’s possible to touch it and keep your hand there but a few more degrees and it would be too hot to keep your hand.
 
Hot means very warm to the touch. It’s possible to touch it and keep your hand there but a few more degrees and it would be too hot to keep your hand.
Unfortunately, this is also far too imprecise, as everyone has a different perception of heat. But based on what you said, I would assume 30° - 40°, which would be normal.
You don't need to worry about the service life at such temperatures.
 
A few rules I have with my PA5 II Plus
1. Don't stack units on top of each other, no DAC underneath it either
2. Raise the unit a bit so cool air an come underneath the unit
 
A few rules I have with my PA5 II Plus
1. Don't stack units on top of each other, no DAC underneath it either
2. Raise the unit a bit so cool air an come underneath the unit
It always makes sense to not place any device on top of an amplifier, but there is no problem with the original feet underneath.
The air circulates thanks to the heat anyway and thereby cools the device. The warmer the device gets, the more air circulates.
But it doesn't hurt to lift your feet either.
 
Using a PA5 II (bought from Audiophonics) in an active system driving one Tangband WB-1772 (8 Ohm - FR 250hz-20khz) per channel at full power output, volume regulated from the DAC , usually - 25 dB, until now the amp runs cold to the touch.
 
Using a PA5 II (bought from Audiophonics) in an active system driving one Tangband WB-1772 (8 Ohm - FR 250hz-20khz) per channel at full power output, volume regulated from the DAC , usually - 25 dB, until now the amp runs cold to the touch.
And that is exactly the problem.
Without specifying the exact temperature, we are moving in a range of at least +/-10°, or more.
If you push two people into 30° water, one of us will say "that's pleasant" and the other will say "that's cold".
Then there is the experience with other devices. Most A/B amplifiers are in a temperature range of 35°-55°, class A even at 60-70°. Based on this, a PA5(II) will feel rather cool. But someone without that experience might find that hot.
 
Using a PA5 II (bought from Audiophonics) in an active system driving one Tangband WB-1772 (8 Ohm - FR 250hz-20khz) per channel at full power output, volume regulated from the DAC , usually - 25 dB, until now the amp runs cold to the touch.
Thanks.

That’s similar to my setup. WiiM Pro Plus > PA II > Wharfedale Diamond 220s 8ohm. Volume controller by the WiiM.
 
And that is exactly the problem.
Without specifying the exact temperature, we are moving in a range of at least +/-10°, or more.
If you push two people into 30° water, one of us will say "that's pleasant" and the other will say "that's cold".
Then there is the experience with other devices. Most A/B amplifiers are in a temperature range of 35°-55°, class A even at 60-70°. Based on this, a PA5(II) will feel rather cool. But someone without that experience might find that hot.
A little common sense please.

@DTTOM37 said “cold to the touch”.
I don’t need to measure the exact temperature in degrees to know that my PA5 II is definitely not “cold to the touch”.
I’m also pretty sure @DTTOM37 or any other person wouldn’t consider it “cold to the touch” if he/she touched it.
 
A little common sense please.

@DTTOM37 said “cold to the touch”.
I don’t need to measure the exact temperature in degrees to know that my PA5 II is definitely not “cold to the touch”.
I’m also pretty sure @DTTOM37 or any other person wouldn’t consider it “cold to the touch” if he/she touched it.
Exactly, because then no PA5(II) can feel cold, at least not at normal room temperature.
The only exception would be a defective device.

A large part of the heat when a PA5(II) is switched on and unused is generated by the voltage regulators, which have to bring the 36v to 12v. Therefore, each of these devices must noticeably warm up as soon as it is switched on. This is simple physics.
 
Mine came on Monday from France.
It sounds very nice...
I did left the amp powered on idle. I'd say it stays lukewarm.
With 21 C degrees in the room, when switched on, the shell has the room's temp and feels a bit cold to the touch.
After 30min and up to 6 hours later, it's only lukewam to touch.
I don't have an infrared temp gun to measure it, but surely is no hot.
 
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I have a PA5II and a PA5II Plus. Both get comparatively hot as described by the OP - "very warm" but touchable. So much so that I have a bad feeling having the PA5II on top of a stack of amplifiers for an active system. All other Class D Amps I have get a lot less warm over time (and have a bigger enclosure). I assume it has to do with small case and implementation of the Amp.
 
I have a PA5II and a PA5II Plus. Both get comparatively hot as described by the OP - "very warm" but touchable. So much so that I have a bad feeling having the PA5II on top of a stack of amplifiers for an active system. All other Class D Amps I have get a lot less warm over time (and have a bigger enclosure). I assume it has to do with small case and implementation of the Amp.
Today used free air next to no other devices and not playing low leveles for an hour the Amp got just warm. However under same conditions other Class D would not get warm at all.
 
I have a PA5II and a PA5II Plus. Both get comparatively hot as described by the OP - "very warm" but touchable. So much so that I have a bad feeling having the PA5II on top of a stack of amplifiers for an active system. All other Class D Amps I have get a lot less warm over time (and have a bigger enclosure). I assume it has to do with small case and implementation of the Amp.
PA5 II and Plus are the same devices and only differ in the power supply.

Without a specification of the temperature of the amplifier and the ambient temperature, your statement is all or nothing. At least it says nothing. People's perception of heat is really very different.

I recently measured 3 Class D amplifiers at a friend's house, and he said that 2 of them were too hot. These two amps were both around 35°, the third cooler one was around 28°. But when I measured the circuit board of the cooler one directly through the cooling slots, some of the components were over 40°, some even at 45°.

The ambient temperature is also important. At around 21-22° my PA5 II and my A30a are around 35.4°, at 26° both are around 37°. Even under high load both stay under 40°, which speaks for a very good cooling concept.

The fact that the housings of your other Class D amplifiers feel cooler when idling says nothing about the temperature of the components, nor about the power consumption. In fact, both can be higher.
Maybe you are just a victim of the heat hysteria when it comes to amplifiers.
 
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