New to vinyl question

Get a copy of Little Feat The Last Record Album and play “Long Distance Love”. To assess bass tracking. It has a very strong bass line that should sound undistorted, unlike Cream albums, which while great music, were poorly recorded. And I’m going to stick up for Jimi Hendrix’ records…starting with Axis, they were excellent!  Rainbow Bridge is a great example. 
TBH, your problem sounds most like your VTF is too low, or you have a wad of accumulated dust interfering with groove contact, as JB opined up top. Keep it clean!

The Sphinx III has adjustable gain for the phono stage.  If the Sphinx II also has adjustable gain, I'd check to make sure it is set at low gain.  The high gain setting would be for a LOMC cart.  You may just be overdriving your preamp on the heavy bass passages?  Not the most likely source of your problem, but it sure would be nice if that's all it takes.

Just circling back to say thank you to all who offered suggestions and insight. I adjusted the VTF a bit, which seemed to help slightly. But I've since upgraded the Sphinx to an RP-5 preamp. The whole system really sings now and no distortion on the bass from my turntable. Thanks again to all. Happy listening. 

New LP Pressings are prone to a excessive Surface Noise and noticeable distortion.

In general I buy through Amazon as I can return a LP as often as I want without too much inconvenience, and I usually end up with a much improved pressing when using this returns option.

When buying Merchandise Only direct from a New and Evolving Group/Bands Marketing Methodology presented.

I am not so critical about the LP's Quality, I bought the 'Merch' to help the Group/Band get a better remuneration than a Streaming Service will provide to them, and hopefully put some revenues in the coffers to help them work towards a new material for release.

I find this purchasing method, more satisfying than searching out a access the their produced material for Pennies, and as a result increase the risk of seeing one more talented group of individuals fall away and get other types of work.  

In context, I would pay decent monies to see a Movie, that is really not of any great interest with Actors that are right for the Job, it is just a Gap Fill form of entertainment, but not really with a stimulus to the artistic talents being presented, that a Musician can present.

But yet it is quite possible to access the music at a Stupidly Cheap outlay, and have endless access, great stimulus and even a growing admiration, and this is all wanted on the Cheap, at the risk of the performers not being able to survive in their ambitions, due to constraints of no finances being remunerated of any real use.

To the OP. One more thing to check. Many turntables, especially ones with a springy suspension, have built in screws, usually hidden from view, that are tightened down for shipping. If your TT has such screws make sure they are not impeding the suspension, loosening usually requires only a screwdriver and a few counter clockwise turns. Check the owners manual.