Think its in the loft, comes with a great story ...
I got it on ebay from south wales (500 miles away but was visiting the area the following weekend). I got there to collect it and it had been the guys father in laws, part of a collection he had as he was into 'hifi'. Quite a nice feeling beeing able to say its going to a good home. Anyway he was really pleased and said " I have another philips its broke and was going to the skip - but seen as you are into this stuff maybe you can take it and fix it ?"
"yes sure I can at least try"
he then left the room and brought me a nice shiny CD100 with all the manuals And let me have it - for nothing at all.
From a search on google 1542 looks like a filter - though I can only guess why they used it, surely cant be cheaper than a couple cheap opamps and resistors. Haven't seen the datasheet so perhaps its quite good performance wise for simple implementation, I doubt they were worrying about sound quality with this CD though !