Power cord for tube preamp w/SF Cremona Auditors?

Good question Lloyd. Good point. I think I may just leave everything alone with the Cremona setup because when things are working well (which it goes w/o saying is very hard to do),
I am loathe to change things (as they really are magic, with these darn little speakers sounding way above their paygrade).
I really am shocked how good this setup sounds, after years of false starts. I heard TAD monitors with Atmasphere amps at the Axpona show recently (about best of show I thought) and my humble setup here somehow sounds better to me, more involving with no fatigue at all, just pure music with lots of resolution but not analytical, even on not-so-good popular recordings, sort of a miracle & much beyond my hopes when I cobbled this together.

For the record:
SF Cremona Auditors (Synergistic Resolution Ref 0.5 speaker cables),

EMM XDS1 (Shunyata Anaconda VX power cable, Stealth Sakra XLR ICs),

Apex Pinnacle preamp (Shunyata Anaconda power cable,

Stealth Indra IC RCA for output),

Luxman L507 used as a power amp (Shunyata Anaconda Helix power cable),

Shunyata V-Ray II (Shunyata Anaconda CX power cable).

And changing phones or trying another headphone amp is always a possibility.

Thanks for the kind words Lloyd, I appreciate it.
I do have 650s, but also HD800s and Beyers & Denons.
The 650s (& previously 600s) were my mainstay for several years.

Grados are just too raw-sounding for me.
These headphones have fine bass (and in fact all sound fine) with some of the other power cords. It's just that the only power cord that works really well with the speakers messes up the bass with the phones. That is why I was focusing on maybe finding a power cord that would be the best of both worlds.
Thanks again.