cd changer

Hi All
done a search on here and found very little although that does not mean its not here .
My cd changer has part number stc50432 on a label on the back and a round connection fitting .
All replacement units i have found have a square or oblong connector .
Does this mean my audio cd changer is old or non standard
The alpine head unit is from factory as i have the original hand book

thanks in advance
Mick

I had a CD player from my 1998 Disco, which was standard factory fit, but it bruk so I got rid of it, but in many ways I wish I still had it, bust though it was. Even though it only had a capacity of 6 discs.
So if anyone has an original one that is still working I might be in the market for one. Although I think I have slung all the connectors too, so it might be a nightmare reconnecting the two.
I then fitted a Blaupunkt head unit and changer but I liked the standard one and it also drove the subs which my new one don't without feckin about.
Also it had a fancy shock absorbing base which I stupidly got rid of and that I really do regret.