3 posts / 0 new
Last post
ejbsk8's picture

A MM 112 RD Fifty with Mid Shift on the distortion channel


I was given a road weary RD 112 Fifty. I've been cleaning it up and it sounds and functions well. The serial number is EN12575. I am trying to learn more about it, but instead of having a Limiter on the distortion channel it has a Mid Shift switch. I have not been able to locate definitive data or the manual for an RD fifty with the mid-shift switch as opposed to the limiter.

I little to no knowledge of electric guitar amps for I am primarily an acoustic guitar player. However, I am willing to learn! :)

I am guessing this is a 1983 model, mainly by the info gathered so far and the sticker on the back.

Any help or knowledge shared about this amp will be greatly appreciated.


PDF icon MusicMan 112 RD Pics.pdf381.25 KB

Nice amp

Hello Ed,

you have a revision E RD-50 amp. The limiter/distortion channel requires the use of a foot switch to be engaged. The mid-shift button changes the voicing of the channel (and only that channel).

Lars Verholt

ejbsk8's picture

Mid-shift switch


Thank you very much for the comment. It helps a lot. I got it in my head that the limiter was a separate function. The limiter clean switch is just a channel switch. The version I have requires the footswitch to activate the limiter/distortion channel and there is an extra feature, the mid-shift switch.

So far I've enjoyed the amp. I ran a Fender Champ 25 SE for years until it finally gave up the ghost. This amp is much better as an electric guitar amp. I've gutted the Fender Champ 25 SE and rewired the speaker. Now I am playing the amp through both the old Fender speaker and the Celestron. Loads of fun!


Log in or register to post comments