I have a fender Princeton amp that has a problem with the chassis. It's an intermittent problem and the speaker is fine. I have another amp that could use an extension cab. My question is can an amp be turned into an amp cab? If so how. The amp I want to make into a cab is a fender Princeton dsp 65. It has a power amp in? Not sure if I can plug another amp into this and instant cab?
You should be able to unplug the speaker from your princeton at the chassis. It should have a 1/4" jack. The 65 may be hardwired. You'd need to unsolder it and attack a new wire with a 1/4" jack to plug into the Princeton. Preferable use speaker cable. Just cut the jack off one end and solder the bare wires to the 65's speaker terminals.
It would probably be better to just get the Princeton fixed. I can't imagine that the speaker in the 65 is of great quality.