I agree with Rhaps - they work, but not without some fussing. I tried it early on and switched to 306 atty's in a hurry (the needle adapter wasn't readily available). I didn't care much for the native 510 cartos back then, either. But the newer 510 cartos such as the Boge LR's and the dual-coils work wonderfully - I really like them. I have about a bajillion KR8 cartos, but they'll just sit for a rainy day.