The PSU offers you seven IDE plugs, two FDD plugs, ATX12V, AUX and 20-pin ATX connectors. Most of the cables have an 18AWG section – that’s the norm for a good 300W PSU.
As I have mentioned previously, this device features active correction of the power factor. It allows reaching a power factor of 95-98% against 70-75% in PSUs without such correction or with passive correction.
The oscillogram of the output +5V voltage looks reassuring: the wave peaks don’t exceed 20mV in average. Short peaks only appear when switching transistors change their status, but such peaks are nearly unrecognizable by the oscilloscope I use.
It’s nearly the same with the +12V power rail, only the swing is higher, but the maximum acceptable swing on this rail is also higher, according to the standard.
I can’t say this is the ideal picture as I saw PSUs with no noise at the output at all, but the noise we have here is acceptable and is not a problem at all.
The unit shows excellent voltage stability. For example, 7% instability of the +12V voltage is considered a good result, and 10% instability is downright poor, so the 6.3% shown by the ZM300A-APF is simply an excellent result.
The test graph shows that the unit produced no significant artifacts like a too-long time it takes the output voltage to stabilize after a sudden load change (if the voltage regulator is bad, the voltage needs 0.5-1s to get stable changing by 100-200 millivolts in the process). Such voltage surges here boast small amplitude and do not last long.
So the ZM300A-APF should without doubt be placed among the best PSUs we have tested so far in out labs as it shows a high quality of manufacture and excellent characteristics (well, these things usually go along together). I can’t call this unit perfectly noiseless, but it uses a good fan and a rotational speed control to make this noise as quiet as possible.