Power cord to add ease and tame treble.

My system comprise of a Ayre CX7; Hovland HP100; Pass X150.5 and JMLab Diva Be. All IC are Cardas GoldRef, SC are Ridge St Poeima. The IC & SC were chosen after extensive in home comparo.

The sys sound pretty good but there is slight brightness, nervousness at the treble. The resolution is excellent. I have tried trivista DAC which warmed up the sound but lost sig. detail, front to back spatial clues. A friend's Cary 303/100 fits in between and is quite nice. Is there a way to tame the treble while preserving the details & reolution using a power cord?
Have you applied any acoustic treatments to the room? That's where I'd look, rather than power cables. Just a suggestion....
Try harmonix studio master.
If you really think about power cord, I suggest you just get the shielded version like the CVH DIY cable for digital source.
Did you try the Cardas Golden Reference speaker cable? I ask because in my experiences the Cardas seems to be quite smooth. The Ridge Street, although quit revealing, was a bit thin, leading towards listener fatigue, IMHO. I should mention that my Ridge Street experiences were with the interconnects, I haven't tried the speaker cables.

As far as a power cord to smooth the treble, try a Shunyata Cobra/Viper/Python, at least on your Ayre cd player. If you're looking to spend less, try a Cardas Golden Reference power cord.
TG Audio 688 on the CDP plus some good isolation under it.
I second the Harmonix Studio Master
Sounds more like an AC issue. What do you have the system plugged into and how is the AC delivered to you system? I will be experimenting with some AC noise products that come off my fuse box prior to the AC coming to my dedicated AC lines and Porter outlets. At my friends home, fixing the AC took away the harshness in his system. Don't buy a power cord until you have fix the AC. There have been several posts about this subject and excellent comments from Sean, Psychicanimal and Lak. Look up their posts on this subject. I was chasing the same issues you were but this makes more sense before you spend money in another direction.

Happy Listening.
Two cords that help with removing treble harshness are Wolff's Carbon Cord and the Ridge Street Power Cords. Both are excellent and worth a try.
If you ask the wrong question you're bound to get the right answer for the wrong problem. Your problem is not the power cord...
Something else to consider looking at your system is that every review I've read about the Ayre CX7 stresses that it that it sounds dramatically better through the balanced outputs to the extent that it's been suggested that one not purchase the player unless intending to use it in balanced mode. Now from what I know of the Hovland pre it's single ended only, so you may have a mismatch right there. Remember it's not just the best components, it's their synergy together. Perhaps you could borrrow a balanced preamp or a different cd player and see how things sound. I'd recommend against using the band-aid approach of a power cord until you look at this issue as well as room treatments and ac issues. Good luck!
I'm with Psychic on this one. A new power cord will not solve your problem.
Try just adding a single Wolff Carbon Source AC cord or Grover/Wolff Empress IC...... very substantial reduction of digital grain/glare, trail periods available. Both cables sold here at Audiogon.

I see you don't have power conditioner, this can help give you smoothness you seek.......but also some can restrict dynamics so must choose carefully here, I like Audio Magic power conditioners but they are expensive.
Its quite a game isn't it?
After many ic and pc problems and yes I have gone the Cardas,JPS Labs,Blue Circle ,Audience route.I do believe cables make more of a difference than components, by quite a large margin.
Try line conditioning and some of the smaller cable guys like
Audio Magic ,and really worth a try "Z-squared" ,personal review soon.Very complete sound with their gear.FWIW
Peter D.
I would try a master pc for virtual dynamics. Install on the your Ayres and listen to your system transform to another level. Good listening!!
A recent posting regarding speaker toe-in reminded me that an easy way to tame a hot treble is to use less toe. The apparent reason: a tweeter's response declines as you move off its direct axis. A freebie tweak! Try it and see.
Like a few have mentioned... A power cord is not going to solve your problems.

Here's part of what I think your problem is...Your preamp is not a good match for your amp. I believe Stereophile reviewed your preamp and the most useful part of those reviews are the measurements. Take a look and I think you'll find that your Pass amp does not have the optimal input impedance to mate with the Hovland.

Also, you may find that your JMlabs are not the right choice for your taste and room. The BE tweeter is an impressive piece of technology, but sometimes great individual parts don't make a great whole - just like combining a bunch of "recommended" components doesn't always make a great system.
Thanks for your posts, guys. I mean it.

Mike in NC. No room treatment. Room has heavy curtains both side wall with couch & heavy rug on wood floor. I am happy with the midrange & base balance now. Room treatment has more effect on low midrange + base?

JMCgrogan. The ridge st. cable was no brighter than Au24, Kimber 3033, which are slightly warm. I really like this cable as it adds a lot of focus and front to back layering to the speakers. The diva be has silver-copper wiring so may have some synergy with silver speaker cables. ( Copper would do too if that is the logic.)

Bigkidz. Nice to hear from you. Its is a dedicated circuit that are shared with a few lights in living room which I turn off. Friend can bring a PS audio P300. Would give it a try.

Jond. Had cx-7 into pass x1 both xlr & rca. No sig. diff for me.

Tried the toe in & out. No fix there.

Guess i should try power conditioner or wolff pc or harmonix pc.

Bigkidz, may be i need an Audiologic MXL DAC.

Thanks guys
There will be no fix until you address power filtration...

I beleive my original question was, have you tried the Cardas Golden Reference speaker cable?

As Big_Kidz and The Psychic allured, you may very well be hearing what noisy untreated AC does to the sonics when the lines are not properly conditioned. But of course, everybody using electricity has dirty/noisy AC.

If you do not have dedicated circuits/lines, then you are also probably getting a double-dose of dirty AC since your digital source would be injecting much digital noise back into the AC (supposedly digital noise is bi-directional) and may very well be carrying over to the amp and/or preamp.

Even if you already have dedicated circuits/lines but no proper line conditioning, you still have AC noise coming into the house and the digital noise will still make it's way back to the service panel and then into your other components from there.

Lastly, I'm not familiar with the sonics of the interconnects or speaker cables you mention. But there are some to many otherwise decent ics and speaker cables that actually induce much grain and hash. So common is it, that this grain and hash is often times mistaken for digital hash from inferior cd recordings.

Other ics and speaker cables will minimize or eliminate this grain or hash leaving you with a much lowered noise-floor and a very pristine, articulate, and significantly improved musical presentation.

I would agree on at least some power conditioning for your digital. Another angle would be Walker Hi Definition Links.
I also agree that power filtration is very important. Once that is taken care of; I found that the Chris Venhaus Flavor 4 pc was a huge improvement when installed in my transport. The presentation became richer and fuller. I bought another one for my preamp. Very reasonably priced. Another great tweak for the digital nasties is ERS paper in the CDP. It takes some experimenting as to how much to use. You'll be pleasantly surprised with the results.
You mentioned that side walls do have curtains, does the treble quality worsens if you open them while listening?
Also do you have any treatment in the front wall, what's between your speakers?
If front wall is too reflective or have furniture in between speakers, that could be a contributing factor to what you hear. If this is the case try placing a blanket between speakers in front wall /furniture to find if this is causing you trouble. What happened? A deeper soundstage might be a pleasant bonus in doing this.
Your feedback.
JMCgrogan. I have not tried the golden ref speaker cables. How do they sound?

There is nothing betw the speakers. There is a fireplace and i am not allowed (family) to put cloth on the front wall.

What constitue proper AC filtration?

Thanks guys. Special Stehno & bigkidz.

Bigkidz, I will definitely try your method. Not much to lose.
They (Cardas Golden Reference) add ease and tame treble. I just mentioned it because it seems that's what you're looking for a power cord to do.
I do agree with the others that dedicated lines are a good place to start. This added a blacker background, improved imaging and solidified bass in my system.
You guys are absolutely right. With the PS audio P300, i'm right where i want it ( at least for now ).

Why does dirty AC affect the treble more than other frequencies?
try omiga audio http://www.omigaaudio.co.uk/. i was using nordost power cords (a mix of shiva and vishnu) and had a rather "obvious" trebble. i home demoed the omiga's and they cured the trebble, making it very natural and smooth, whilst seemingly adding an octave to the bass and increasing the detail levels, and to top it all off, they added an amazing sense of presense to the sound. a real "you are there" kind of feeling. perhaps the biggest step my system has taken. tony the proprietor is also a top guy. i have no conection to the company other than being a very happy customer!