Edriz
AK Member
As MrMonster has suggested, the speed issue sounds like you received a wrong sized belt. Not that the speed adjustment has that great a range, but it should produce some difference, so I would make sure the belt is the proper size.
MrMonster also touches on something I've been meaning to write about.
Those felt washers in the suspension system of the 498/598/698. They provide that "piston" action that Empire describes, but I found that removing them improves the sound by more than an order of magnitude.
They provide a nice amount of damping, but since when my Uncle first got his 698 I noticed that the turntable didn't have the complete freedom other suspended tables had from vibration transmitted sounds like thumping on the plinth or acoustic feedback.
So in a fit of experimentation two years ago I removed the felts from my 598III and after readjusting it and all, I found not only is the turntable now completely impervious to any sort of influence from being tapped on, acoustic feedback etc, but a whole low layer of grunge and "haze" is no longer there. Plus, and I admit I cannot explain this, subjectively the bass seems to go deeper and with more authority than it did before the felt removal.
The downside is, naturally, that you need to have a really solid support for the thing now. That's not a concern for me, as my listening room floor is a concrete slab, but for others, doing this mod would make wall mounting almost mandatory. Plus you lose the ability to use the cueing facility as touching the cue lever causes the whole platter/arm to swing and jump up and down. (I rarely use it anyway. I've always been a "fingerlift" man.)
But if you can do it, I would at least try it. It does a LOT to help an already good sounding turntable sound even better.
The first belt I received was way too big but the seller sent me the right one the second time. Or as far as I can tell, its the correct one. Its slightly smaller then the one that came with the turntable. I'm guessing the original may have been worn.