Power Cables and Affects on Timing (and speed)?

Yes, just as true of the trailing edge. You will need a room that is clear of excessive reflections as this will blur the effect that these sorts of improvements make. In a less optimized system you may get much less impact

@dave_b  Very interesting and what a great story/lesson. 

@randy-11 Thank you for the link. I'm aware of archimago's work.

@folkfreak  I got very lucky with my room. It does need some treatment which will happen in the near future. At my normal listening levels the room is not a factor, and is surprisingly well balanced per my preferences. 

David my guest timing is more connected to speed and transient, tonal balance my guest is not connected to timing but it might help though.

I made the same mistake once again, but remembered I had forgotten to swap out the power cord from the Lyric Audio Ti 140 MkII to the Pass XA-30.8 much sooner this time.

On this occasion, I also had the good fortune of having a fellow audiophile and friend on hand evaluating Single Ended IC cables (for the Lyric amp) with me.

The differences between the two cables were clear and our preference for my normally used cable was clear as day. Since both of us were ’critically evaluating’ the system, the differences we picked up on went far beyond just an improvement in timing.

(In case the question comes up...the power cables were powering the Pass XA-30.8 via a PI Audio UberBUSS....and were Audio Art and Triode Wire Labs)