The LP should sound as good or better than the CD.
With the stylus in the groove check to make sure the botttom of the cartridge looks to be close to parallel with record from the side and isn't tilted when looking from the front. If the tracking force is close and it's not twisted way left or right in the headshell looking from the top then it should sound way better than you describe even if it's not optimized.
Perhaps you got burned with a defective cartridge. I wouldn't trust a used cartridge from anybody. Is the cantilever straight? Is the stylus broken off?
You could buy an entry level cartridge to test with.
With the stylus in the groove check to make sure the botttom of the cartridge looks to be close to parallel with record from the side and isn't tilted when looking from the front. If the tracking force is close and it's not twisted way left or right in the headshell looking from the top then it should sound way better than you describe even if it's not optimized.
Perhaps you got burned with a defective cartridge. I wouldn't trust a used cartridge from anybody. Is the cantilever straight? Is the stylus broken off?
You could buy an entry level cartridge to test with.