Hi Maron6168,
I used a Markbass 121p for about 8 years, adding a Markbass speaker cab when needed—which was seldom.
Great little amp—until the speaker blew.
Markbass won’t sell you a new speaker—at least not in the US: you have to ship it to an authorized service center (which is very costly), then pay for the speaker ($$), as well as installation (more $$).
By the time you’re done, you may as well just buy a new amp.
I replaced my speaker with another suitable one, and continued to gig with it, but it never sounded as good.
Ultimately, I bought a Fender Rumble 800– a fantastic amp: it has a bit more power, 2-10” speakers, excellent tone controls; and while it’s a bit larger, the weight’s about the same—29lbs.
If I’d known then what I know now about the Markbass service policies, I would’ve bought a Rumble in the first place!