Thoughts re: cartridge/interconnects

My "system" is about 10 years young and comprises a Linn LP12 with Sumiko Premier FT3 with a Linn K18 cartride; CP SA-3000 & SA12, Vandersteen 2C's, interconnects are MI 330's. Because I live in a small market which has only one store which carries cartriges, your recommendations/suggestions would be appreciated. I'm not enthralled with the cartridge. Thoughts about a cartridge under $500 for the system. The local dealer carries only Krado. Secondly, the interconnects and tubes in the amps are from the original date of purchase. Any recommendations on (1)better interconnects and (2) replacing the tubes in the amp. The SA12 works; no tubes are blown, should they be changed just because they are "OLD"? My girlfriend may want to change me. Thanks for your feedback.
first upgrade your interconnects. i would suggest the walker interconnect. expensive but they are still a bargin. i also can't say enough about walker's high def links. these thing literally transformed my system into music. after then address your other concerns: cart/tubes. good luck. mike
I fear I disagree with Mrug on this one. Interconnects really shouldn't change a whit over time, barring physical injury and corrosion at the jack. And in any event, except for either really bad IC's or really sensitive systems, the sonic difference in changing IC's is probably going to be remarkable only for its sublety. I don't recall anyone suggesting the MI 330s were particularly bad, so....

I can't recommend a cartridge, but it would be the second thing I looked to, AFTER testing and re-biasing your tubes (or replacing them, if the tests show they're done; and the re-biasing assumes the CP allows/requires such). But if your tubes check out, and the pre- and amp are functioning properly, then you'll know whether the cartridge is really what is making you unhappy, and proceed accordingly. (Bonus points - if you do the tubes first, other sources will sound better too!)

Priority #1 Get the tubes first. You are probably loosing so much with 10 year old tubes.It is where you start. You can't hear what anything else is doing, till you do.
Sorry; should have given you a listening "test" to see how good the tubes are. Play something with lots of dynamics,and bass, sort of loud. Even if your system passes this you are likely loosing in other areas. Your tubes don't die from age / just hrs. of use.
Thanks to all for your responses. Have ordered new tubes from "Kevin." After they are replaced will make decisions re: the cartridge.Again, thanks.
Golf- I had a pair of early MI 330 IC that did show noticeable corrosion when I opened them up. This may have been a unique problem, but I wouldn't rule out the very worthwhile improvement of more current cable designs. Do the tubes, then the cables (I'd recommend the Coincident Speaker Technology IC and speaker cables), and then the cartridge upgrade if desired. Just my .02.