I'm waiting on a Tiny Terror combo to arrive atm, and a thought just popped into my head which raised a few questions.

Firstly, am I right in thinking the combo is a Tiny Terror head + a 12" speaker enclosed in one box. It's not an inferior amp or anything?

And if so, were I to buy a cab later down the line, would I be able to plug that into the combo and use the amp as though it didn't have a speaker attached, or would I have to buy a separate amp?

ESP LTD EC-1000 Vintage Black - Orange Tiny Terror Combo

Tama Superstar Custom Hyperdrive w/ Sabian Cymbals
If it's got a speaker out, then yes, you can stick a cab on it at a later date. If it doesn't you can still attach a cab, you just cut the wire to the speaker, wire a jack and socket to it, and if you want to attach a cabinet (turn off the amp) just switch the cable from the internal speaker to the cabinet.

All combos really are is a head and cabinet in the same box. Some people mod their combos by removing the head unit, putting it in a custom box, and modding the speaker cab into a seperate cabinet.
Peavey Rage 158
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the combo is the head and speaker in one unit. And yes you can run an external cab with it but you'll have to unplug the speaker in the combo if you don't want it to work.