In 2002 I bought a beatup Rick M12 amp. It is a 40 watt via two 6L6 power tubes. The amp had been through the mill and was made around 1959. The carying handle was a dog collar!
http://i36.photobucket.com/albums/e5/ao ... km12-1.jpghttp://i36.photobucket.com/albums/e5/ao ... ntrols.jpgIn 2005 I sent it to Kendrick Amps for a complete rebuild. It needed tubes, rectifier, and an OT. They recovered it and replaced the grill cloth.
http://i36.photobucket.com/albums/e5/ao ... ckm122.jpgIt sounded great! In Jan 2010 I had Jeff Andrews at Andrews Amp Labs in Atlanta tweek it up a bit. He put in a weaker preamp tube as it would dime out at 4:00 on the vol. Now the vol control is much smoother and it doesn't dime out so soon. During a phone call with Jeff I mentioned that I wanted to add a 15" cab to the 12" speakers. Jeff told me that it had 10" speakers in it. Well, the M12 came with two 12" Jensen speakers so I assumed that Jeff was mistaken.
When I got the amp back I measured the speakers. Sure enough, it had 10" speakers in it just as Jeff had told me but the front grill openings were for 12" speakers. Strange.
After a little investigating I discovers the truth. Someone had installed a SECOND baffel board with 10" opening to the orginal baffel board. It was screwed and glued in place. I pulled the baffle and the speakers.
http://i36.photobucket.com/albums/e5/ao ... hholes.jpgAfter removing the screws the second baffelboard was securely glued in place. I used a regular steam iron to heat up the baffel board and use a putty knife to work the second baffel board free. After about 45 minutes I got it free.
http://i36.photobucket.com/albums/e5/ao ... hholes.jpgThe 10" speakers in it were made in 1975 by Eminence. My guess that sometime in the 70's, someone did an "upgrade" to the M12 and replaced the speakers with 10" instead of the factory 12" size.
The Rickenbacker M12 came with Jensen 12" P12Q speakers. I decided to restore the amp to the orginal speaker specs so I ordered a pair of Weber 12A125-A 16 ohm. These are vintage correct P12Q speakers. Wired in parallel that would give an 8 ohm load and with a 15" Weber 8 ohm external speaker that would bring the total load to 4 ohms.
http://i36.photobucket.com/albums/e5/ao ... eakers.jpgPutting the amp back together, I installed the 12" Webers and gave them a go. They sound great, much better than the 10" Eminence speakers that were there.
I had J Design Speakers make me a matching 15" external cabinet and I ordered a Weber 15" California speaker for it. Sounds great and looks perfect.
Here's the rear view of the amp and cab:
http://i36.photobucket.com/albums/e5/ao ... ckrear.jpgNow for the front.
http://i36.photobucket.com/albums/e5/ao ... deview.jpgI've only had a few hours playing the stack but it sounds sweet!. The speakers need more time to be broken in but I am very happy with this '59 Rickenbacker M12.