Neito said:Thanks to everyone who's giving feedback; I now realize that even if I build a new cabinet, it won't give me the desired effect, so I've decided to buy a new head first, then embark on a cab-building adventure a little later.
Neito,
Nothing should stop you from building a cab now, it will come in handy later.
Also, check the manual for your amp- if it was intended to use an extension cab, your amp will put out more power with it connected. Connecting an extension cab will drop the impedance load on the amp, and dropping the impedance load on an amplifier allows it to produce more power. You will definitely get some benefits. Just keep within the impedance limits of the amp.