An M-11 amp with 4 inputs?

[lhakim]

Hello,

I'm new here and would like to get some information about a 1960 Rickenbacker M-11 I recently got that seems to be a bit of an anomaly.

First of all, it has four inputs rather than the usual 3 you see on M-11's. It would appear that the fourth input was added by a later owner, as the chassis was clearly punched and silk-screened for the standard 3 inputs originally, but internally, the wiring, soldering and components look uniform which would suggest it either left the factory that way or someone went to considerable trouble to convert it to 5E3 specs. Interestingly someone on ebay was recently selling a 1950's M-9 that looked to be originally drilled for 4 inputs.

Secondly, the cabinet is wider than late 50's M-11's I've seen, and the speaker (a 1955 Jensen "Professional Series" P12R) is mounted in the center of the baffle board and not off-center.

I can't post pictures of the amp, but it should still be up on ebay under item # 2570026497.

I would really like to know if this a later version of the M-11 amp, and whether anyone here has seen or owned another one like it. Any other information anyone can provide such as how far into the 1960's Rickenbacker offered the M-11 would be greatly appreciated!

Larry