Newbie Issues: Grace F9 with Micro Seiki DD-40


Hey all - total newbie here. I’ve only been researching phono setups for a few months. I ran into some serious playback issues after trying to replace my cart. Wondering if anyone can tell me what is causing it?

A friend actually gave me a DD-40 with original MA 505 tonearm (14 g effective mass) and stock headshell. So I have been thrown into this (awesome) world of hifi in an effort to live up to this amazing gift. The DD-40 came with a Stanton 681eee cart and I immediately replaced the broken stylus with an LP Gear replica as a placeholder before upgrading. To my ears it sounds really really good after calibrating it properly (I am an entry level digital audiophile but this is my first analog experience). 

Because my setup is MM for now I have fixated on the Grace F9 series as my first cart upgrade. I bought a used F-9 L on ebay from someone with great reviews and an easy return policy. The problem is the playback is absolutely horrid:

- distorted muffled sound
- incessant skipping
- needle gets stuck between tracks

I have recalibrated and readjusted many many times including starting from scratch and calibrating the entire TT and tonearm setup. Every time it still sounds the same. While doing the same steps but going back to the Stanton cart works just fine. I even replaced headshell wires and have nice cables (Kimber Kable and Van den Hul) and a Furman power conditioner. It’s running through the phono input of a Pioneer SX 838. 

When I increase the tracking force beyond the recommended range for the Grace the skipping issue gets a bit better but not really. And the sound always remains distorted and muffled - that never improves.

Visibly the cart, cantilever and stylus look totally fine meaning not bent or broken. But again I’m just a newbie and have not put anything under a magnifying glass.  

So all that said, with the issues I described above, what do you all think is the problem?

1) Worn out needle?
2) Bad / bent cantilever?
3) Busted cart?
4) Bad newbie calibration?
5) Cartridge / tonearm mismatch?
6) Something else?

Any help would be greatly appreciated - thanks!

YL
hauie88
Post removed 
It wouldn’t be the first time in history that someone bought a used or vintage phono cartridge online that turned out to be grossly defective. That is my opinion based on reading your history. Don’t blame yourself; blame the seller. This is a not uncommon happening. Try to get your money back and return the cartridge. Although I think the Grace F9 is a wonderful sounding cartridge, when it works, It might not be the best idea to be buying used cartridges from anonymous persons on the Internet, for a beginner, or even for an experienced audiophile. My advice would be to buy a brand new cartridge from a reputable dealer. At that price point there are several very good candidates that will at least approach or equal or exceed the grace F9 in sound quality.
You might try to remove the stylus assembly and then reinsert it.  Sounds like a bad cart, but maybe the stylus isn't quite making contact. 
@lewm thanks I totally hear you. This seller has 100% positive and thousands of reviews and has already accepted my return so hopefully it goes well. Is there another MM cart you’d recommend given what I’ve written above?