Right, so if i buy the adslnation adsl faceplate, and i connect my phone extension to the back(filtered)and want to connect my adsl to the a and b terminals, which colour wires do i connect to a and b?
Also, with my faceplate upstairs (unfiltered) been a standard bt socket, how does my modem connect to this when it is rj-11?
When you take the front off the master socket faceplate make a careful note of which pairs and which colours are connected to which terminal numbers. Then replicate the same on the replacement but connect the extension that you'll be using for the router to the unfiltered terminals.
Connect your router to the extension faceplate by using a microfilter as a converter.
PS make sure you buy a disposable Krone tool (~£1) with the faceplate so that the connections are correctly made.
The wires for terminals 2 & 5 go on B & A respectively.