Difference between CWT 550AD and ADP?

Hi, I'm considering picking up the Channel Well Power supply because I heard the ADP is the exact same as the Antec 550 TruePower series. The problem is I don't know the difference between the Two.

-AD
http://www.cwt.com.tw/product/ATX/A/cwt-550ad.htm
-ADP
http://www.cwt.com.tw/product/ATX/A/cwt-550adp.htm

It seems that the ADP is a 230Vac which wouldn't work too tell in North America . But others in the forum say they have the ADP, so maybe it's not 230Vac and it's something like a Active PFC opposed to Passive?

Any insight here woudl be greatly appreaciated

Thank you.

The P is indeed relating to PFC... either one will power your system fine. The A series is pretty much identical to the Truepowers - the D in the model number refers to dual fan... there are single fan versions too IIRC (AS or ASP).

Thanks for the info, so I assume the ADP version = Active PFC
while the AD version is Passive PFC, surely no PFC at all?

I believe it denotes active PFC - not sure if the non "p" models have passive, but it won't hurt performance if it has none at all. It's nice to have for efficiency's sake, but I don't think it's a requirement yet in the US or Canada.