Yes Mathias, as Chr said, the amp can be disconnected from the bottom. The speaker column actually sits on top of the amp section, and 5 long threaded rods go through the base, amp, and speaker to hold the sections together. If you unscrew the 5 nuts underneath, you can slide the pieces apart. You'd then need to get some shorter threaded rods and slide just the base back unto the speaker, without the amp between them.
I have my own hope of someday building a class-A amp and powering my pentas with that!
Austin