Equipment Protection, Monitoring Electricity

I am not contradicting Elizabeth's advice, which may be right, but if you were really concerned about it, you'd have to hire an electrican and i would think you'd want somebody with experience with commercial ap't buildings- depending on the size and age of the wiring in your building and whether you can even access it (is this a house or a building?), your electrician might be able to poke around a litlte, and take some measurements. Sometimes, intermittent problems don't exhibit themselves- if your voltage is good at the outlet when the guy/girl measures, it may not be at other times. And, perhaps, look into those power regeneration devices. There's a ton of discussion about them here- and they may make sense in an apartment context where you have little control over the AC set up inside. There are also discussions about the relative merits of 'conditioners' and isolation transformers. And remember, none of us have any control over the AC power being delivered to us. That's why all these products.

I'm no electrician, and there are some very knowledgeable people on here who can really explain it, but let me understand the facts: a transformer of the utility company blew? And that is what you think fried your amp? Very possible. I think that's one reason why people have surge protectors, but I'm not sure a dinky little consumer appliance type surge protector could handle that. If I have the facts right, I would assume that the power company has now replaced the faulty equipment on their end. But, you don't have any idea what may be wrong in your apartment building. I would assume that the power company has responsbility up to the meter, and after that, if there is faulty equipment, or stuff that got fried when the transformer blew, it is the landlord's responsibility, which as you said, means nothing.
Perhaps you can: call the power company and ask them if a field person could come and inspect the line up to your building and take some measurements; maybe if the power company person is righteous they would help you out and check the power in your ap't- and big maybe, give you a clue whether your building is in violation of code or there is some obvious problem resulting from the transformer issue; find a local electician friend or pay one who would be willing to take a look at the current in your apt- it is pretty simple to measure with a meter, but you sound like you don't have a clue, and inconsistencies in power may be intermittent- usually worse during the day because of demand.... but in an apt, with everybody home at night, you may be having more issues then.
The other thing to explore by some searches here, and advice from people smarter than me, is whether any of the regeneration devices will work if the current going into them is really inconsistent. i don't know- the whole point is that they 'regenerate' the power so it's cleaner, but you'll probably have to pay a few thousand bucks for one and i'm not sure it will work.