it's an SL-5200. I've gone back and read some online material, and have done my best to set the proper alignment (using the free protractor tool), counter-weight, anti-skate, and tonearm height. I think right now the tone-arm height needs the most refining. Should the stylus tip be completely vertical, or will it always have a slight pitch.

The sound quality problem only seems to crop its head on select LPs - my newer and better-conditioned LPs seem to have little problem. I am thinking that a major factor of the sound quality may simply be the quality of vinyl. Which is unfortunate, as I like to buy bargain stuff.

Also to clarify, I have historically used the carbon-fiber brush before every play, but now I clean each record with the wet discwasher solution once.