Choosing a cartridge for a vintage TT.


I have a Denon DP51F direct drive TT. It is aesthetically and functionally perfect. I'm currently using a Grado Red 2 cartridge and it sounds pretty good. I've replaced the stylus but I'm thinking it's time for an upgraded cartridge. I realize this not a high end table by today's standards. How far should I go with a new cartridge? What would be a good compliment for the tonearm, which is not conventional by today's standards? My amp has MM and MC phono stage.
Any suggestions would be appreciated. For further info My speakers are KEF R3s with the R400B sub and my amp is a Yamaha AS2100 integrated. I listen to mostly Jazz and classic rock.
chasda
A Denon 103R mc is a good recommendation and a step up in SQ! I added one to my new Pioneer PLX1000 TT. Contrary to the naysayers here Denon has been making excellent and affordable mc cartridges for decades! For $300 the 103R is a "best buy"!
roberjerman thank you for the insight. I have heard of that particular cartridge before and it does get good reviews. But it is a low output MC and I'll need to check the specs on my phone stage to make sure I have enough db for this cartridge. Thanks again.
I recently got a Tannoy Micro TM33 with an original Stanton 681EEE. I had to replace the stylus. I'm totally blown away by clarity, balance, separation and accuracy of this cartridge. Both the Tannoy and Stanton date from the 70's. A 681EEE can be had on eBay for around $150. I'd buy another in a heartbeat.