The Quick Answer
- You can use the line-out speaker jack on your combo amp to connect a speaker cable directly from your combo to the external cabinet.
- You can disconnect the speaker and head parts of your combo, and solder a jack onto the head unit cable to connect it an external cabinet.
Can you run a tube amp without the Cabinet?
you have to have a cab. The amp head MUST have a load connected to it, otherwise all the power generated by the power amp section has nowhere to go, so the output transformer will blow.
Can you use a solid state amp as a cab?
yes, you can use the MG's line-out without hooking a speaker cab up to it. SS state amps don't have an output transformer and are effectively loaded by the speaker cabinet, if the speaker cabinet is absent then the amp sees an 'infinite load' which still properly loads the amp.