Brand New Vinyl Static and Pops

I would double-check that the stylus connection wires are properly seated and the stylus alignment is correct. The cartridge should have specs indicating what to set the anti-skate to. The blue might require a higher anti-skate setting. If everything checks out correctly and you’re discharging any static electric buildup before playback, I suggest swapping the cartridges to see if the problem goes away. If so, then the cartridge itself could be a bad cartridge.

If your brother just swapped out the cartridges, then I would double check what your turntable's settings are against the specs for the Blue.

Try a cartridge with a microline or Shibata stylus. Superior tracking IMHO.

I have never seen a cartridge that came with a written spec for anti-skate. And I doubt AS has anything to do with the JJ problem of ticks and pops. Of course if he’s applying way too much AS, that’s a problem per se.

It sounds like this is a combination of two things- a cartridge problem and perhaps also setup.

The cartridge could have been dropped and the magnet knocked out of alignment. This can cause all kinds of weird stuff while the cartridge looks fine. Since the muffled quality is in both channels this is a possibility.

I'm not sure how setup would cause the cartridge to sound muffled, but certainly it can cause mistracking, which manifests as ticks and pops in loud passages as the cartridge loses contact.

Am I missing something? It looks like the OP is not actually cleaning records, and is not subsequently cleaning a very dirty stylus.