Well,if it has the octal socket it is an 8 not an 8b. The 8 was made between 1959-62. 30/watts vs. 35/watts in the later 8b's. The original price on a 8 was $250. The 8b was made from 1962-1966.Typically, matched up with the 10b tuner and the 7c pre amp(tube) 7T (solid state). Little known, there was a 7P that was a different tube version of the 7.Best of luck with your Marantz.
Olenorge
Olenorge