Power cord for tube preamp w/SF Cremona Auditors?

I've recently been agonizing on a power cord for my Apex Pinnacle Preamp/Headphone amp. As a preamp, the original Shunyata Anaconda Alphas are perfect, just mellowed out enough up top to take the brashness off my Sonus Faber Cremona Auditors' tweeters, making these speakers sound magical, and the bass is nice and controlled.
Unfortunately, the bass is too soft with this cord for headphone usage.

I have tried these cords, and none sound as perfect a match for the speakers as the Anaconda Alphas, as they all sound a bit fatiguing or forward or brash:
Shunyata Anaconda CX,
Stealth Dream (preamp version),
TG SLVR & 688s,
I think there is some synergy going on with the (same generation) Shunyata Anaconda VX on my EMM XDS1 cd player.
Query whether you wish to spend money on a diff cable...which may change the sound thru your Cremonas...or change headphones.
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.
You know what? that seems like a fantastic set up. You've done a great job...and enjoy it! What phones are you using? I like the Sennheiser 580, 600 series. You may as well. Super comfortable, natural sound...good luck and pls keep us posted.
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.
And the bass on those is too soft? hmmm...Grados (maybe)?
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.
As long as the power cord is rated to carry the maximum load from your component, and is properly wired, grounded and shielded, it should not Color the sound of it. Pop the cover off your unit and take a look at the power supply and the iec inlet. You'll be shocked to notice how unsubstantial it looks.

You would be better served by utilising a isolation transformer between the wall and your unit. Power cords really are a non issue. And a source of tremendous profits for the people that peddle in that mythology.
Try the Cardas Clear Beyond....
I would suggest trying the Cerious Technology power cord - Only $349 and guess what, blows away anything more than 5-6 times the price.  Bob is using graphene now and they are simply incredible. With a 30 day money back guaranty, a no brainer. 
The Cerious Technology does seem popular.