Is LP distortion the record or the cartridge?

@mglik , What speakers are you using?
There are certainly times when the reissues are better than the original particularly when it comes to older popular music. The quality of the pressings was not near that of classical music and in the late 50's and 60's recording engineers doing popular music were not as experienced. As an example the early masters of Zappa's first 4 or five discs were terrible. The remasters are fabulous. The reissue of Weather Report's Sweetnighter is significantly superior to the original. I would rather have a good clean pressing at 9/10ths sound than a scratchy one at 10/10ths.

Dear @mglik  : "  I think the culprit is worn vinyl.
I do have a lot of used records. Guess I will flag the worst ones.
I think the greatly increased performance of my new Atma MP-1 just picks up and amplifies the wear issues. "

That could be true if your before phono stage was a " terrible " poor design to cover those kind of distortions.
Do you own or can put your hands in other cartridge just to make tests?
I asked before which phono stage was using and I would like to ask again. Could you share/disclose that phono stage?

Thank's in advance,
R.

I have Tetra 606 speakers. AMT with ATC dome midrange in an open baffle. and a 10” woofer in ported box. Very accurate. I don’t have another cartridge but am waiting for my Lyra Atlas SL.
My former phono stage was the John Curl one in my Audible Illusions preamp. My guess is that much of my current detail with the MP-1 is, in fact, picking up much more of what is actually in the groves.

Dear @mglik  : Assuming that the head-amp along the Audible Illusions you owned were in good condition both units are not so bad enough to not reproduce the kind distortions you are talking about.

Assuming that you are loading the Shilabe with same or very near impedance value than in your former units then what you are experienced/listened could be generated inside your new unit or if by coincidence when you connected the new unit the Shilabe started with a suspension " problem " or a stylus tip " problem .

If I was you I will look probably with an audio friend that permits to mount your Shilabe and listen to it and if not distortion at all then your new phono stage has a trouble and you need to know it even if with the Lyra does not happens. Is up to you.

R. 

The first thought is that the cartridge is not properly tracking. Am using a Miyajima Shalabi

@mglik How old is your cartridge?