Test Setup

All measurements are performed utilizing ten electronic loads (seven Array 3711A, 300W each, and three Array 3710A, 150W each), which are able to deliver over 2500W of load and are controlled by a custom made software. We also use a Picoscope 3424 oscilloscope, a CHY 502 thermometer, a Fluke 175 multimeter and an Instek GPM-8212 power meter. Furthermore, in our setup we have included a wooden box, which along with a heating element is used as a Hot Box. Finally, we have at our disposal four more oscilloscopes (Rigol 1052E and VS5042, Stingray DS1M12 and a second Picoscope 3424) and a CEM DT-8852 sound level meter. In this article you will find more details about our equipment and the review methodology we follow. Finally, if the manufacturer states that the maximum operating temperature of the test unit is only 40°C then we try to stay near this temperature, otherwise we crank up the heat inside the hotbox up to 45-50°C.

Voltage Regulation Charts

The following charts show the voltage values of the two main rails, recorded throughout all load range.

Voltage Regulation Graph

The following graph illustrates the deviation that the main rails registered. The lower the deviation the better the voltage regulation, of course.

Efficiency Chart

In this chart you will find the efficiency of X-MAN 90W at at loads equal to 20-100% of the PSU's maximum rated load.

Voltage Regulation and Efficiency Measurements

The first set of tests reveals the stability and the efficiency of X-MAN 90W. The applied load equals to (approximately) 20%, 40%, 50%, 60%, 80% and 100%, of the maximum load that the PSU can handle.


Efficiency with 20% of max rated load starts rather low but afterwards it easily reaches the levels that Huntkey promises. It peaks with 60% load at 91.06%, a high enough reading. Here we should state that power adapters like this one generally have much higher efficiency compared to desktop PSUs, because they have only one DC output (in this case two) instead of the five that desktop PSUs have.
Voltage regulation at 19V is tight enough at 1.61% deviation and at 5V is a hair above 3%. Considering that 5V will be used only for charging devices, the registered voltage regulation is excellent for this rail. Also during our tests we noticed that the temperature of the X-MAN stayed at low levels, unlike other adapters we have seen/used.

5V Efficiency

ATX spec states that the 5VSB standby supply's efficiency should be as high as possible and recommends 50% or higher efficiency with 100mA load, 60% or higher with 250mA load and 70% or higher with 1A or more load.
In this case the X-MAN doesn't actually have a 5VSB rail since the 5V rail is only available when the PSU is operating (idle mode) thus the 19V are also available at the same time causing a negative effect to the overall efficiency of the 5V rail. However since the future buyers of the X-MAN most likely many times will utilize only its USB port to charge a device, we are going to test the 5V rail utilizing exactly the same procedures we use in normal PSUs with proper 5VSB rail. So we will take four measurements, three at 100 / 250 / 1000 mA and one with the full load that 5V rail can handle.


Since we couldn't test the 5V rail at standby we expected that the efficiency readings at idle would be low since 19V in this mode is active, too. It may not deliver any power but only the power that its voltage conversion circuit consumes is enough to affect the overall efficiency readings.
With only 0.1A and 0.25A load at 5V, efficiency is lower than 40% so it is not a good idea to charge your phone or camera with the adapter operating in idle (without powering/charging your notebook). If you charge a tablet pc and "pull" more than 1A out of the 5V rail then efficiency is way better.

Power Consumption in Idle

In the table below you will find the power consumption and the voltage value of the two rails when the PSU is in idle mode (On but without any load at its rails).


As you can see the X-MAN, even at idle, is ErP Lot 2010 compliant and this is very impressive taking into account that the 19V circuit is also active. Good job Huntkey!