I have a Janome 9000 about the same age, and I don't think it matters what you use as long as it's good thread and bobbin and needle have the same thread. I've just bought some Aurafil because so many people here have suggested it. Qshop owner said it really is good because it doesn't make "fuzzies" in your machine. I was there to have my Janome adjusted for some tension problems which I might have caused when I was cleaning out the thread bunnies under the bobbin case.