Marantz 8-8b question

I bought a one owner Marantz tube amp today. I went for the Quad 57's and ended up with the marantz too. I'm not very familiar with this amp and believe it to be an 8--thats what the model number says. However I just want to be sure that it's a 8 not an 8b. Is the 8b labeled a "b" or how else would I identify it? Thanks for the responses!

Your question has an easy answer.Turn the amp you bought around to the back side.On the left side is an octal socket(black),this was used to plug a Marantz mono preamp directly into the Marantz amp(because it needed high current).This feature only exists on the older less popular Marantz 8,the 8b does not have an octal outlet socket.Good luck,any other questions fire
i have to admit that i thought that even early 8b's had the octal socket. i also thought that the 8 said model 8 on it and the 8b, model 8b.... i could be wrong.....
This one has the octal outlet and says 8. Walks like a duck, quacks like a duck, probably a ... However, I've never seen 8b indicated on a amp and just want to be damn sure. Also replacing the two top filter caps at the sugguestion on my tech and would like to know where to buy originals or, more likely, repos. Thanks for the responses.
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.