I agree with Audiofeil and Buconero117: Keep the Denon. A sub $1K belt drive TT would be a lateral move at best. I recommend:
--Spend a little money on isolation--maybe platform the turntable on a butcher block cutting board with Vibrapods or gel pads under the cutting board
--Maybe try another turntable mat--perhaps a Herbie's Way Excellent in the same thickness as the Denon mat
--Upgrade your cartridge by replacing the Red stylus with a Blue. It's a little cheaper than buying a whole new cartridge. There's quite an improvement in transparency and detail when you go from a bonded to a nude stylus. For a bigger jump in quality (and price), go for an Audio Technica AT150MLX. They go for $300-350 if you know where to look (LPGear and audiocubes2.com).
--Spend most of your upgrade money on a better phono stage. Read up on the A-gon reviews of the ones in your price range. And in addition to the Graham Slee, look into the versatile and highly configurable Musical Surroundings Phonomena II at $600.
--Spend a little money on isolation--maybe platform the turntable on a butcher block cutting board with Vibrapods or gel pads under the cutting board
--Maybe try another turntable mat--perhaps a Herbie's Way Excellent in the same thickness as the Denon mat
--Upgrade your cartridge by replacing the Red stylus with a Blue. It's a little cheaper than buying a whole new cartridge. There's quite an improvement in transparency and detail when you go from a bonded to a nude stylus. For a bigger jump in quality (and price), go for an Audio Technica AT150MLX. They go for $300-350 if you know where to look (LPGear and audiocubes2.com).
--Spend most of your upgrade money on a better phono stage. Read up on the A-gon reviews of the ones in your price range. And in addition to the Graham Slee, look into the versatile and highly configurable Musical Surroundings Phonomena II at $600.