In a very large saucepan, melt the butter with the olive oil and garlic. Stir. Stir in the clams, broth, wine, salt, black pepper, and red-pepper flakes. Simmer for 10 minutes, allowing some of the liquid to evaporate.
While the sauce is simmering, cook the linguini in salted water until al dente, drain, and add to the clam sauce, along with the parsley. Toss well and serve immediately, with the Parmesan cheese on top or on the side.