Well, it seems you answered your own question. Replace your stylus. If that doesn't solve your problem, the issue might be your RCA cables or tonearm.

What many people don't understand is that it takes ALOT to wear out a record. I mean, you would have to play a record about a good 1000 times before you'll see any sort of real wear/tear on it. Why do you think they last so long? Besides, record wear doesn't sound like that. With TRUE record wear you'll experience lots of skipping from your stylus, as the grooves have worn down. Also, you'll get alot of pan issues, where the sound goes in/out left/right side. The grooves of a record are a V shape, and the left side of the V carries the left signal, and the right side carries the right signal. With record wear, usually 1 side will wear out quicker than the other, and that's why you'll get inconsistencies with sound.

Unless you play the same record over and over again for the past few years, you wont see this kind of wear.

Replace your stylus first, then have your RCA cables and tonearm checked. Try cleaning out your tonearm with 99.9% PURE ISOPROPYL ALCOHOL and see if that does anything.

Good luck

DJ PRO LAB

you say the problem happens on both tables and on the same song
if it was the needle or cartridge i would suspect only one to have the problem so im going to go with record deterioration, try a new Record!