Wait, you purchased these cables ("they were manufactured that way..") or did you make them yourself?

CAT6 is much more difficult to make at home (to spec) so you have to pay close attention. If you are going to make them yourself (and are not experience in making cables), I would suggest EZ Jacks. About as fool proof as you can get.

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Denon 4520, EPIC80/500/VP180 Speakers