Grado Stylus Upgrade

For a noticeable upgrade in SQ, you need to move up to the Grado Gold. I'm assuming you haven't experienced any hum with your Thorens, so the Gold would be the way to go. The Grado Black and Gold carts are not insulated so they can pick up motor noise from certain brands of TTs.

As long as your current TT setup does not hum when the tonearm moves toward the center of the record, then you can move up the Grado line.

http://www.needledoctor.com/Grado-Gold1-Prestige-Series-Phono-Cartridge?sc=7&category=926

The Ortofon 2M Blue is in the same league as the Grado Gold, and is very widely respected. It has a different sonic signature, not as warm as the Grados. Either cart would take your analogue setup to a higher level considering your budget.
One more...a Denon high output MC cart may be the best bang for the buck. It's output gain will match a MM phono stage.

If you change to a different brand, you'll need to take into consideration the compliance of the cart. IOW, you need match the mass of the tonearm with a cart of the proper size.

There are also many MM cartridges that will better the performance of a Grado Black. Many also have more advanced stylus profiles. The Black's stylus has the subtlety of a brick, I've seen knitting needles with finer points. ;-)

Check out Raul's endless (11K posts and counting) thread on MM vs. MC for recommendations.

When you say the old cartridge sounded better, in what sense?

I owned the Grado and Thorens combo played through a Rega Elex and it sounded a bit overly warm and lethargic with my vintage B&W speakers. all good components bult too much of a good thing.

I think my old Thorens came OE with an At95e which was cleaner and more precise sounding. I love the Grado sound but it works better on my Technics 1200 than my Thorens. I would get a cleaner tighter cartridge like the Ortofon 2M series or even an MC as others have suggested.

Thanks for all the advise.