It's not certain, but that Sony may well be a Liteon in Sony clothing!
h**p://www.cdrinfo.com/Sections/Articles/Specific.asp?ArticleHeadline=52X+CD%2DRW+Roundup+Vol1&Series=0&index=1
Ok, it's the E1, and it's actually a firmware hack to ghet there, as it was unreleased at the time.
Sony often seem to deliver an "E1" for drives listed as "A1" - and the dismantled picture is copelling evidence of a Liteon core.
The board, in fact, says 32123S - but is clearly not using the "3S" chipset!