Have never heard any of the Wyetech amps, but can tell you that after more than 5 years of ownership, the Opal pre is one of the most amazing, satisfying components I have owned in more than 35 years of this mania. It is the one component in my system I never even think of changing, and like many of us, I am constantly looking to "upgrade." It probably will outlast me! And Roger Hebert is a very responsive designer/owner if you ever have any problems (unlikely) or questions.
Neal
Neal