I can use any thread I like on my 15000 - even cheap thread from India and China, provided I check that it is wound tightly - a few spools from some of the batches are pants - then I just stick a red headed pin in the reel so I know to check stitching on my other machines before using.
"With all its sham, drudgery and broken dreams,
it is still a beautiful world. Be cheerful. Strive to be happy." Max Ehrmann