Dear Needle, In your initiating post, you said that the system "sounds like" the tt is playing "slow". At that point, PBN and others offered a possible fix for that problem with your particular tt. But in this last post, you say that you checked the speed of the tt, and "all is right". If indeed you checked the speed with a reliable strobe device or other during this warm-up period and could detect no problem, then perhaps you should describe in more detail what you are hearing. Obviously your perception of the music as being slow does not tally with your data on tt speed. Bad tubes will not do this, either.
Whats wrong
Turntable seems like it playing slow for the first 10-15 minutes of play, after that all is fine. Turntable has about 600 hours on it. Hoping its the belts would appreciate any thoughts.