Why does my vinyl sound so bright?

The wall shelf is mounted directly into the studs, however it is an inside wall as an exterior wall was not an option. Regardless, the wall shelf has made a significant difference as the system is on the second floor, previously when walking across the room the TT would bounce, now it is very solid and stable.

I'll look into the mutliple things given here and report back after some experimenting. Thanks everyone, for helping this vinyl imbecile without making me feel like more of one.

Okay, this is weird. I adjusted VTA a tad and validated VTF at 2.0 and now music sounds garbled and warbly coming out. I'm guessing the cartridge may have bit the dust or be biting the dust. Maybe the cantilever got damaged somehow when I moved it (although I had the arm secured and it was a pretty short and uneventful trip from rack to wall.)

Any further thoughts?

Cleaned the stylus, the mounting is visually good, and it measures properly. I'm going to take it (tonearm and all) tomorrow to a local shop to have it looked at, I'm relatively certain the stylus is damaged/significantly altered somehow. It sounds like rocks and water are running under it during playback, I don't know much, but I know this sounds like something much more than an alignment issue.

Thanks for all the help!

Thanks Tobias, and everyone who chimed in. I actually learned quite a bit yesterday from all of your replies, so I'm a few degrees less of an imbecile (about my vinyl rig anyway) and one step closer to having it up and running.

One more quick thought, as to the wall shelf. I didn't really clarify well on that point. I moved the table in December, it has played and sounded fine many times since the move. The brightness, now rocks and water sound, was new in the last week or so.

So assuming the Blackbird might be damaged, It appears a retip on these is fairly pricey, any thoughts in the direction of the value/dependability of a retip versus spending $5-700 for a new cartridge?

Cantilever appears straight and I don't have 50x of higher. I'm going to take it in to a place that does tomorrow. Yeah, I am NOT playing any LP's based on how this sounds. Chipped might make some sense as it would play, just terribly...