Agree with others you likely have a problem somewhere. If you still have your old amp or can borrow one I’d definitely try that to rule out the Luxman as even new gear can have issues, and it sounds like you didn’t have this distortion problem until you started using the new amp or turntable — no? Also, blown speaker driver or crossover component — is the distortion from both speakers? If it is, I think it points further to a possible upstream problem. A bad cable or dirty connection somewhere could also be the culprit, so I’d try cleaning all your connections, which is a good thing to do anyway if you haven’t lately. I assume you’ve cleaned your records and stylus, but sounds like a dirty needle kinda sound you’re describing. You’ve got some great speakers, so if you still like their overall sound it’s worth a little frustrating troubleshooting.
That said, as an owner of speakers from a manufacturer no longer in business I could make a case to sell them before parts become an issue — no fun sitting on eggshells wondering when a speaker component might fail. Plus, it’s not exactly an unenjoyable chore to go out and listen to some new speaks even if you don’t end up buying. Toward that end and given you’re coming from Thiels, I’d recommend listening to Vandy Quatro, Joseph Audio Perspective 2, and Usher BE-10 if at all possible. Hope this helps, and best of luck.
That said, as an owner of speakers from a manufacturer no longer in business I could make a case to sell them before parts become an issue — no fun sitting on eggshells wondering when a speaker component might fail. Plus, it’s not exactly an unenjoyable chore to go out and listen to some new speaks even if you don’t end up buying. Toward that end and given you’re coming from Thiels, I’d recommend listening to Vandy Quatro, Joseph Audio Perspective 2, and Usher BE-10 if at all possible. Hope this helps, and best of luck.