What Cables for Quad 11-12-21-22 ?Tubes Anyone?

Greetings fellow A'goners.I'm wondering what speaker cables you Quad dynamic speaker owners have tried & settled on?Did bi-wiring have an impact on the performance,positive OR negative?Is anyone driving them with pure tube front ends?Thanks for your input.
I have been using the Signal Cable Silver Resolutions since 2008 in bi-wire config. I have been very happy with Signal Cables. Used Nordost 4-flat bi-wires previously. The upgrade was significant. And yes, bi-wiring made a big difference for me, even when I was using the Nordost 4-flats.
I do not have experience with tubes and cannot comment on that.
Signal are very well made and spec'd cables, another no BS cable that is well made are those by Blue Jeans.