KLEI Absolute Harmony RCA Review

Absolute Harmony 2
As well as a pair of KLEI gZero10 Interconnect Cables that he sent for my review, Keith Louis Eichmann (KL) of KLE Innovations had also included a set of four KLEI Absolute®Harmony RCA Plugs for this review.

So I immediately installed the
KLEI Absolute®Harmony RCA Plugs onto on my own DIY Home-Brew silver/copper interconnect cables and proceeded with the burn-in process - since that was going to take around 150 hours.

I also had an identical set of my DIY Home-Brew Interconnects with a set of
KLEI Pure®Harmony RCA Plugs already installed and burned-in for comparison, so this assessment is all about how much better the new KLEI Absolute®Harmony RCA Plugs are compared to the KLEI Pure Harmony when installed on identical interconnect cables

So, what are the actual differences between the various Harmony RCA models...

Outwardly, each of the RCA models conform to KL’s latest design and as such, have an almost identical appearance, with the exception of the colour of the logo on the collar that grips the the RCA socket.
What are the other differences? - to the layman, mainly in the metals used for the Signal and Neutral pins...
  • KLEI Copper Harmony (Gold logo) - Signal (KLEI PureCopper) Neutral (KLEI PureCopper)
  • *KLEI Silver Harmony(Silver Logo) - Signal (KLEI PureCopper) Neutral (KLEI PureSilver)
  • KLEI Pure Harmony (Rose Logo) - Signal (KLEI PureSilver) Neutral (KLEI PureSilver)
  • KLEI Absolute Harmony (Blue Logo) Signal (**KLEI PureSilver) Neutral (KLEI PureSilver)

*KLEI Silver Harmony
- is the one anomaly in in the line-up in that the KLEI PureCopper Signal pin has an extra thick silver plating which makes it almost as good as solid silver from an IACS conductivity rating perspective.
**KLEI PureSilver - Each RCA has it's very own formula to enhance electron flow based on the materials used the thickness of those materials, the plating used and who knows what else.
  • But from the KLEI web site, the description for the Absolute Harmony states: "Signal/Ground pins utilize an even higher spec KLEI PureSilver™ with >106% IACS conductivity"

Also - for clarity, KLEI PureCopper and KLEI PureSilver are
"proprietary alloys" formulated by KLEI Innovations.

If you would like to read the official details of the Harmony RCA Plug line of products then I would encourage you to visit
KLEI Harmony Phono/RCA which also has a nice explanation of exactly what the IACS rating is all about.

Moving On ...

Now, I had only just finished my review of the
KLEI gZero10 Interconnect Cables (which utilizes the Absolute Harmony RCA's), so my ears were now accustomed to some very high definition musical performances.

I thought it best, if I first
"re-acclimated my ears" to the sound of my interconnects with the Pure Harmony RCA’s installed, so I plugged them in and had them playing for a couple of days.

During the acclimation period I was very surprised at just how good they sounded. No, they were not as good as the
KLEI gZero10 Interconnect Cables, but they were still, very adept performers!

For me, there were now two questions in my back of mind...
  • How good is the Absolute Harmony RCA Plug as a standalone product?
  • How much did it contribute to the excellent performance of the KLEI gZero10 Interconnect Cables?
The Change Over...

Now, I had only listened briefly to the interconnects with the
KLEI Absolute Harmony RCA’s installed when I first started their burn-in process and my initial impressions were very favourable. There were distinct improvements in dynamics, bass extension/control, imaging and details etc.

But now the interconnects with the
KLEI Pure Harmony RCA’s seemed to be sounding just as good - it had me wondering if I had suffered the "new component syndrome"
  • it generally happens when you install something more expensive - ergo, it must sound better.

Obviously, only way to address this was to change over to the interconnects with the
KLEI Absolute Harmony RCA’s installed on them and play a few tunes.

Right from the first track - it was like a flashback - to that first brief audition - but something was now quite different.
  • I didn't consciously discern the improvements in terms of the various metrics associated with performance evaluation, i.e. imaging, dynamics, details etc..., but, my level of enjoyment of the music had increased significantly.
  • The music just seemed more complete, with more vim & vigor. It was crisp, clean and bold and my foot seemed as though it was tapping with a mind of its own. Every now and again the goose-bumps kicked in - it was a very interesting and pleasing experience.

Once I recovered from that initial
"beguilement", I started selecting tracks that I believed would make the various metrics more discernible and therefore, be able to make a more tangible assessment.

Hey! - Maybe - "foot tapping" and "Goose-bumps" should be considered a metric? Happy

To evaluate details, one track in particular sprang to mind - "Bad" by U2, from The Best of 1980-1990 album. The opening bars of this track is two solitary guitars that were recorded with precision. One guitar is picked, like a high pitched
"chime", highlighting the clarity of the recording, with the second guitar gently strummed in the background.

  • This gentle strumming really demonstrated just how good the KLEI Absolute Harmony RCA was at conveying minute details, since you can actually hear the pick hitting the next string in a single strum
  • "Oh boy, what a..." - OK, so you must think I'm being incredibly anal here, after all, why would that particular facet stand out? - Well, after playing guitar for over 45 years that particular strumming sound is something my ears have become acutely accustomed too and when I hear it in a recording, it has a tendency to leap out at me.
  • Alas, the KLEI Pure Harmony RCA was not quite able to perform to this level of detail.

For dynamics, I simply selected "Walking on the Moon", by The police. Again, the opening sequence is overloaded with a powerful bass drum beat, incredibly fast rim shots on the snare drum, some nice cymbal work and piercing guitar chords.
  • The KLEI Absolute Harmony RCA conveyed these extremely crisp dynamics with amazing dexterity, clarity and exceptional detailing. This was by far the fastest, most detailed RCA I had ever heard.

To assess the imaging prowess of the
KLEI Absolute Harmony RCA, I selected a track "Fragilidad", from an album by Sting, i.e. "Sting: 1985-1994.
  • This track had produced a very wide and deep image with the KLEI Pure Harmony RCA, but the KLEI Absolute Harmony RCA was able to extend the depth of that image and provide a little better focus on the various instruments within it.
  • One other facet of this recording that stood out was the high frequency detail extension of the KLEI Absolute Harmony RCA, which enabled it to convey the very fine "whispery textures" of Stings voice.

About the only metric that was left to assess was low-end performance. For this I normally turn to various Pipe Organ tracks, since they normally contain excellent low frequency detailing.
  • Sure enough, Widor: Organ Syphony #5 in F Minor, Op.42/1-6. Toccata: Allegro, by Daniel Chorzempa was able to highlight the exceptional low end detailing provided by the KLEI Absolute Harmony RCA.
  • But just for fun, I had to include "Mas" from the album Mi Plan, by Nellie Furtado. Simply because it has some of the most detailed low-end synth work in my collection. This track confirmed that the KLEI Absolute Harmony RCA has the best low-end detailing of any RCA plug I have ever tried. The extended bass was bordering on subsonic, but the details and control within those very low frequencies was exceptional, providing textures only previously heard using the KLEI gZero10 Interconnect.

One last observation pertains to the
"smoothness" the KLEI Absolute Harmony RCA conveys...
  • It stands to reason that if an RCA is capable of resolving to an extremely high level then it would allow for waveforms across all frequencies to be reproduced with far greater sonic accuracy.
  • I found that the upper register of violins on classical tracks to be significantly smoother and far less shrill.
  • Also the reproduction of vocals had a much better control of sibilance that made for a smoother more natural sound.


So, after hours of listening, swapping and re-swapping of interconnects and replaying the same tracks many times, I think that a fair assessment might be...
  • The KLEI Pure Harmony RCA Plug is an exceptional and technically adept performer, that delivers fine details, dynamics, spatial imaging, and an extended bass performance, with amazing clarity and dexterity. Something many other RCA's can only aspire too.
  • The KLEI Absolute Harmony RCA however, transcends those "standard metrics" and delivers a performance which leaves you with a smile on your face, while tapping your feet and simply enjoying an incredibly rich musical performance.

So, back to my questions...

How good is the KLEI Absolute Harmony RCA Plug as a standalone product?...

  • The KLEI Absolute Harmony RCA alone will not elevate the performance of your interconnects to the level of the KLEI gZero10 Interconnect, but it will allow your interconnect to perform to the highest level it is capable of.

How much did it contribute to the excellent performance of the KLEI gZero10 Interconnect Cables? ...

  • I have absolutely no idea! - Yes, they allow the details to be transferred etc. etc. But the improvements the KLEI gZero10 Interconnect Cable brought to my system was exceptional. The only explanation I have is that the KLEI Absolute Harmony RCA is capable of conveying much more detail than my own interconnects are capable of.
  • The KLEI gZero architecture and materials however, capitalizes on the full capabilities of the KLEI Absolute Harmony RCA to achieve a significant improvement over my own interconnects.

So, why would you use the Absolute Harmony, as opposed to the Pure Harmony, or the Silver harmony or the Copper Harmony?

I use the Absolute Harmony because currently, I believe there is no other RCA plug capable of performing to the same level.
  • However, as with everything in life, one's budget can be a deciding factor, so the Harmony Range provides an RCA solution to fit several budgets. The Copper Harmony is an excellent performer and each successive model extends the abilities of its predecessor to provide a musical performance of the highest calibre.

So there you have it. If you are looking to replace your RCA's...
  • I would advise you to first consider the architecture and materials used in the construction of your interconnect.
  • After all, there is absolutely no point (i.e. from a cost perspective) in putting a Formula-One engine in a car that does not perform to the same level Happy
Just make sure you pick a product from the KLEI Harmony RCA Plug line-up!
And give it a full 150 hours of burn-in before assessing the performance

My Review System:

  • Custom turntable with Denon DL103(modified) phono cartridge on and Audiomods Arm with one piece silver litz cable + KLEI Pure®Harmony RCA’s

  • Simaudio MOON LP5.3 RS phono stage

  • Schiit Bifrost USB DAC with UBER analogue upgrade

  • NAIM 5i integrated amp (has a passive pre-section)

  • Gershman Acoustics Sonogram speakers

  • KLEI gZero6 Speaker Cables

page6_blog_entry52-page6_blog_entry40-two-thumbs-up-2 A highly recommended product!