This special made tube board can take a lot of different tubes.

These tubes have been tested with the V1.08a board: IN-16, IN-14, IN-8-2, CD66, CD61, GN6, ZM1080, ZM1170, ZM1172, ZM1174, ZM1230, ZM1232, ZM1175, ZM570, XN3, Z573M, Z574M. Of course there are much more tubes that can be soldered directly to the tube board.

It will fit directly on the clock pcb V1.08 as a sandwich construction or via a cable connection.