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The 20 amp version is Superb on the PS Audio P20 At Underwood we looked for two years looking for the right cable supplier. We finally found the source that makes cable for much of the industry. Our power cables are sold by other manufacturers for 5-10 times our retails. We sell them Internet Direct with low overhead and no dealer profits in an attempt to bring some sanity to the cable business.
The $1600.00 Diamond Xtreme uses twice the material as the $1100.00 Diamond and is designed for high and ultra high current devices. It uses 18 separate cores of 16 gauge 8N OFC copper plated with
70 microns of extruded pure silver. It is insulated with FEP Teflon. The custom weave we use is optimized for maximum performance, ie, inductance and capacitance. State of the art carbon fiber IEC power plugs are used. It is available in 20 amp or 15 amp versions. Both have 15 amp wall plugs. Both are available now at our Covid 19 sale at 40% off.
We have them in both 15 and 20 amp IEC's.
ln the Tone Audio review of the standard Diamond cord they said:
keeping with the current world situation, I commend Core Power for
offering a major deal at a time like this to keep you all rocking. I
suspect that if you audition one in your system, with familiar music,
you’ll want to keep it. We’re keeping the review sample and purchasing a
See the entire Tone audio review at: https://www.tonepublications.com/review/the-core-power-diamond-power-cord/
Positive Feedback said of the Diamond cord:
I keeping the Diamond Power Cord? I am. I think it is well built and
when I look at the other power cables I have on hand, it clearly is
built better than anything I have seen under anywhere near its price
Diamond Power Cord gets my recommendation if you are a believer that
after market power cords make a real difference. If you do, go try one, I
think you will likely end up keeping it."
The 6 foot Diamond Xtreme retails at $1600.00 in 20 amp form and $1500.00 with 15 amp IEC.
Either at $999.00 during this sale
1) Aloha Walter, I received the Deep Core and more recently received the
Here is some customer feedback on our new cable line:
Core Diamond AC cable. Today, I received the receipt - thank you. I
could not wait, I connected the Deep Core to the wall via the Diamond AC
cable and turned the system back on. I played music. Wow! The
outstanding system I had before became even better. Deeper more
detailed bass was my initial response. After a while a female vocalist
began singing and I was drawn into the room where the system resides.
Incredible detail and vocal nuances became evident in such intimate
detail. My system sounded good before but now, Grandiose!!!!
2) By the way, the 8 foot pair of the Core Power speaker cables I
purchased from you are the best I have ever heard on my system,
mirroring the same high quality as your other Deep Core products. They
have transformed my system from very good to magical!
Thanks for everything and your professional mannerism and expertice, JS
3) Wally, Yet another "Oh My Goodness", what have I been missing all these long years!
I thought the Mac 601 mono-blocks were just hyped old tech with pretty
blue dials. After getting the new Diamond Xtreme cords, it was as if a
window opened and the heavy curtains were pulled back, and the sun, the
birds, the whisper of the wind in the leaves, and the neighbors arguing 4
blocks away could now be heard in extreme detail. What I difference!
Really, really big change. Its like taking the cotton out of your ears
and hearing why you spent so much $$$$ on this addiction in the first
place. Like audio heroin!
I'm glad I've already paid for my daughter's education!
And, all this time I thought I knew what good stereo was. I'm already in audio heaven! How much better do it get? Bruce S.
4) Walter, These Gold power cables are great and not just for the
price. I put one in the office system and was blown away so i replaced
the $1000 dollar one on the Mcintosh in the main system and the Core is
better. I will try the interconnects this week.
5) Walter, I have been in this hobby since 1970 and a dealer for
certain products since the late 1990's. I have had many different power
cords with great results, but I never thought I could get the
performance that are offered by your cords at the prices you offer. I
feel they are equal to cords costing at least 5 or more times. I have
not had the opportunity to try all that is out there and could not
afford some even at dealer pricing. I have done preliminary listening
with all of your cords in my system and I am utterly amazed. I do not
know how you do it, but I am a believer. At this point I do not need to
go to any other cords. Cannot wait to hear what the Equi=Core and
Deep=Core will offer. I will talk to my customers and local audio
6) “I swapped my Nordost Baldur for the Power Core Diamond Speaker
cable about three weeks ago. I try to take note of my equipment
performance (for my own memory) - this is the first time I send an email
with my notes to someone else. I thought Walter deserved it. I had the
Nordost for the last 10 years, after a love affair with Audioquest. I
tried cables from other brands but ultimately went back to the Baldur.
My system is comprised of Sonus Faber Guarnieri, two subs Syzygy 10”,
Odyssey Stratos Monoblocks SE, PS Audio PW DAC and Transport and
Bluesound Node 2i. I spend
money wisely - I have three teenager kids and college is looming ahead. For example, I
kept the SF Guarnieri for over 20 years, because all my listening
sessions with other speakers did not bring substantial improvements
unless I would have to spend two-three times what I had spent on the SF.
I love music, but I avoid spending money for what I would only
consider “marginal improvements”.
In come the Diamond Speaker Cables. I bought them at about half the
price of what I had spent on my Baldurs years back - Walter’s claim of
providing a high multiple of their value tempted me.
Once swapped I was hit by initial strong microdinamics that impressed me
(in my definition: ability in the reproduction of music to change
rapidly to changes in the recorded performance tone, e.g. going from PPP
to FF and viceversa), but the sense of stage width and depth was not
better than my Baldurs, nor was I convincer of details retrieval. I
swapped back to the Baldurs, which confirmed my initial impressions. I
decided to persevere and let the Diamond break in for two weeks. This
weekend I gave it a serious listen:
Microdynamics were better than the Baldur’s - confirming my initial
impression - but now: details pulled out much more vividly than the
original listen, most importantly, there was an overall sense of
presence and scale that took me to a heightened level of performance.
No matter what the music. Billie Eilish “was in the room” with her
young sultry/rasping voice, Pink FLoyd Wish you Were Here guitar attack
popped out from the center right of the soundstage, the dynamics of
Bach’s Goldberg Variations were more present and “lifelike” - one step
closer to a real close up performance - Gould was humming along
passionately. The 2nd movement of Abbado’s Van B’s 3rd symphony was
more present than I heard before in my system, the sense of scale of the
orchestra was stretching outside the back wall of my listening room.
Enough said. Can a cable make such a difference in a system? It did
in mine. I am keeping the Diamond and my Baldur’s will soon hit e-bay -
anybody’s interested?” Angelo
7) Walter, These Core Power power cables are great and not just for the
price. I put one in the office system and was blown away so i
replaced the $1000 dollar one on the Mcintosh in the main system and the
Core is better. I will try the interconnects this week. Rick
8) Walter, just a few words on the C/P Diamonds. I now have 2 Diamond
Power Cables, and 1 Diamond XLR Interconnect. I will be buying more! As
you have said, they are THE BEST. Nothing but music, black background,
WIDE--TALL--DEEP soundstage. Treble, bass, and mids are perfect!
Layering 2 die 4!
I am hearing technicolor sound like never before! Each additional cable
has been like an expensive upgrade in hardware. And their ability to
convey the emotion of the music is magical. Just one final note...I had
been using some (HFC) High Fidelity Cables, ridiculously priced, you
know, the ones with the silly-ass magnets? Core Power Diamonds crushed
'em. Now I feel like a dummy having wasted my money on them---NEVER
AGAIN. From now on its Core Power, baby, YOU BETCHA! Thank you, Walter,
for bringing out another sensational deal.
9) Hi Walter, Thank you.
I’ve been thinking that needs to be said. The past few of days have been
a new step up in my listening experience, and are very much in line
with what I’ve been pursuing for years and years with one upgrade after
another. With the Equi=Core and Diamond power cables, the really telling
part is how much clarity there is even at the very lowest levels of
listening; there’s real bass coming from my 15” woofers at whisper-quiet
levels! And of course there’s even greater detail when the volume is
higher. Yesterday I stopped in my tracks when a classical harp piece was
playing and between movements I heard the harpist’s feet change pedals.
I have absolutely no idea how upgrading the power feed to my system can
have such a dramatic effect on the quality of the sound, but there’s no
denying what my wife and I are both hearing.
As I ponder that while we both sit wordlessly stuck in our seats
listening to one piece of music after another, I realize it’s because of
you and what a remarkable business you have. Your passion for great
sound is obvious, but also how much you want to share it with everyone
possible by making it as affordable as possible. Your website features
brands I’ve only seen mentioned in the high-end audio press, or that
I’ve never heard of, but all of which are clearly top-notch in the world
of audio, at price points that are much more accessible to those of us
who might not be as well-heeled as others. Emerald Physics? Wyred4Sound?
Deep=Core? Wywires? Wireworld cables? I certainly would have never
known any of these first-hand without Underwood Hi-Fi.
I know that I could have put together a pretty good system from other
vendors, both local and online, but to get to where we are now would
easily cost double or triple what you charge. And for that I thank you.
Oftentimes in the world of business too many good things are treated as
expected, and not recognized for how good they really are. I felt this
is my opportunity to rectify that at least just this once, and to let
you know how much I appreciate you and your company.
10) Finally got round to trying the Gold power cables and I gotta say
they are are amazing. Mind thoroughly blown! I might have to find some
cash for a few more. Pierre
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Brands carried: Ampsandsound tube electronics, Audio Alchemy, Audio Space tube electronics, Black Ice tube electronics, Bob Carver
tube amplifiers & loudspeakers, Burson Audio, Core Power Technologies A/V power conditioners and cables, DSPeaker room correction, EAT Turntables, Emerald Physics speakers &
amplifiers, Focal headphones, Gallo speakers,
Graham Slee, HifiMan headphones, Iso-Acoustics, LSA
speakers, turntables, headphones & electronics, Lehmann phono stages, Marantz Reference, Melco servers, Mofi
Electronics, MrSpeakers headphones, Musical Fidelity, Music Hall, Ortofon
cartridges, Outlaw Audio, Peachtree Audio, Project turntables, Pure
Audio Labs DAC's, Quad, Raal-Requisite headphones, Rethm speakers, Scansonic
speakers, Silverline Audio speakers, Soundsmith cartridges, Spread
Ampzilla amps & preamps, Sumiko cartridges, Sweet Vinyl pop &
click filters, Syzygy wireless subs w/room correction, Wireworld, Wywires, Wyred 4 Sound, Zesto Audio tube electronics