WBT Topline or Nextgen RCAs for Pass X250

Probably neither will make much of a difference. But why not ask Mr Pass at the Passlabs forum. Cheers

I would go with topline 201E . pure 5N copper vs 99% copper alloy on the Nextgen.
One piece construction which is almost unbreakable ( vs the cheap plastic Nextgen.)
Eddie current effect on female connector? not sure if it even get a good contact when using Eichmann plug.

Any joy you might gain by a 1/2% improvement (doubtful) would be negated by the recovery from surgery to repair the slipped disc you'd get from moving this amp to the workbench. Any time you move a component, especially a heavy power amp, you risk a scratch, bent heat sink or worse. As we say in the south: "If it ain't broke, don't fix it". Sit back and enjoy the music.

Agree with Elgordo. Big amps are not light.