Interconnect Connectors

KLEI Pure®Harmony RCA Plug - Turtable Review

If you’ve read the reviews of the KLE Innovations products on this site, it should be no surprise that I would at some point in time get around to installing the KLEI Pure®Harmony RCA Plug onto the one-piece silver litz loom installed in my Audiomods tone-arm that supports a Denon DL-103 moving coil cartridge.

Pure Harmony RGB
Turntable Background:

My Turntable started its life 32 years ago as a Rega Planar II, but over the years, after applying a series of modifications and upgrades (please see Turntable Mod's and Denon DL 103 Tweak for details) it has been transformed into a device with outstanding performance characteristics.

The only things left over from the old Rega turntable is the lid and the on/off switch.

Call me sentimental. Happy


The installation of the KLEI Pure®Harmony RCA Plug was very simple; the most difficult part of the operation was removing the stock RCA plugs, which had a crimped cable strain relief, but soldering the extremely light gauge wires was a doddle, thanks to its redesigned signal and neutral tabs.

Once installed, all that was left to do is burn them in - for 200 hours –
c’mon KL, really?

That’s an awful lot of exercise, finding an album, changing sides, putting them back on the shelf. No wonder audio streaming is getting popular. Gasp

But in reality…

Well, 200 hours may be the optimal burn-in time recommended by KLE Innovations for ultimate playback quality to prevail.

However, for this particular application, it appears you don’t have to wait that long for some really mind blowing improvements to be heard from your treasured analogue rig.

Initially, the
KLEI Pure®Harmony RCA Plug has a tendency to be a little bright and more than a little edgy, at least on my system. It took around 20 hours for that to settle down and transform into a very smooth and incredibly detailed performance. Which was nice, because with 180 hours left on the clock, I was giving some serious thought to installing the RCA’s onto an interconnect and letting my streamer and DAC complete the burn-in process – a much less time consuming approach.

At around 30 hours I became very impressed with the performance improvements.
  • Dynamics were very fast and extremely crisp.
  • The image is deeper than before, but there is more spacing between the instruments both left to right and front to back, e.g. each “section” in the orchestra (i.e. violins, violas, cellos etc.) have significantly more width to them.
  • The timbre of instruments having more details sounded even more natural
  • The venue acoustics are outstanding and really immerse you into the performance
  • The improved clarity in complex orchestral tracks allowed them to be played louder without distortion – 1812 with digital cannons anyone?

But the one outstanding quality of the
KLEI Pure®Harmony RCA Plug was their transmission of incredibly fine micro-details that seemed to bring a “new reality” to my vinyl collection, especially some older live recordings.

It was apparent on the very first track I played,
Baby Please Don’t Go from the 1973 album Better Days by Paul Butterfield, featuring Ronnie Barron, Amos Garret, Geoff Muldaur, Christopher Parker and Billy Rich.
  • I dropped the arm and was returning to my chair, but I never made it. As soon as the track started playing I spun around to listen more intently, standing, the sound so totally different from any previous plays.
  • The extremely fine details of the bottleneck sliding on the strings was just downright eerie, like a ghost from the past. Many tracks sounded as though they were recorded in a gospel hall with two mikes and a stereo reel-to-reel. The natural reverberations are melded superbly with the musicians and their vocals and then reproduced in my system with a haunting reality.

For me, this was a complete jaw-dropper. I’d heard some very expensive systems that may have approached this level of reproduction, but I never expected my current configuration would be capable of such a refined and detailed presentation.

And all this was due to the KLEI Pure®Harmony RCA Plug? - You got it!

Some other albums that grabbed my attention, mainly because of the amazing reproduction of those extremely fine details include…

  • The Doctor, by Doc Powel - with his beautifully mellow jazz guitar, piano, drums and bass. But the outstanding instrument for me was the superb reproduction of the drums, especially the cymbals. Again, the reproduction of the natural reverberations from within the venue is a significant contribution to the reality portrayed.
  • Songs From The Wood by Jethro Tull (1977) – I’ve mentioned this album in previous reviews, where I found the vocal harmonies to be the most profound of Tull’s “signature sounds”, but after installing these RCA’s the reproduction of those vocals to this level of detail is astounding.
  • Boomers Story, by Ry Cooder (1972) – again, I ‘ve mentioned this album in previous reviews and again I mention the superb reproduction of his use of the bottleneck.

What’s a Bottleneck?...
  • A “bottleneck” is a tube of glass or metal that the musician slides on the strings over the fretboard.
  • Why am I so enamoured by this particular sound?
  • Having played guitar for over 40 years, many of which were spent dabbling in the art of Delta Blues, provides one with first hand experience of the very distinctive sounds the bottleneck makes,
  • e.g. just the vibration of the strings against the bottleneck when simply sliding it up the strings is a detail seldom reproduced in a believable manner.
  • But when it is - goosebumps! Happy

Moving forward a few years …
  • LEGEND: The Best Of, by Bob Marley and the Wailers (1984) – whilst not really in the same league as those above for it’s natural venue acoustics, the studio tracks are extremely well engineered and yields the widest image of my entire collection) – which now exceed the width of the speakers by a couple of feet.
  • Down to the Moon by Andreas Vollenweider (1986) – again – not a really natural sounding album, but exceptionally well-engineered. The outstanding feature of this album is it’s micro details and associated dynamics, i.e. those little details you hear when strings are plucked, like the fingernail catching the plucked string – as with a Harp. This album brought Harp music to the mainstream back then, but it has never lost it’s appeal and now with the vastly improved reproduction it can be enjoyed all over again, like a new album.
  • Raising Sand by Robert Plant and Alison Krauss (2007) – for me, this was one of those albums you regret buying. You know, you get it home and it just doesn’t do anything for you. But it stayed on my shelf, seldom played. Well, that was until I started to audition the KLE Innovations product line, after which the album perked up and things started to gel. It seems that before installing KLEI products I was missing so many details in many of my recordings. In this case the album sounded lackluster and had no excitement – not any more, it reproduces extremely fine details and vocal textures from these two exceptional artists are outstanding.

One last artist that really presents a challenge to any system, particularly where clarity is concerned, is Mike Oldfield, remember
Tubular bells? There’s also Omadawn, and Five Miles Out among others. But the one thing they all share is big sound, lots of multi-tracking instruments and incredible details, a lot of which can be lost. Well not any more – with the KLEI Pure®Harmony RCA Plugs in the system those details shine through with scintillating glockenspiels, astounding tubular bells, crisp distorted guitar licks and airy background woodwinds – absolutely stunning.

I haven’t mentioned any classical recording, mainly because it would lengthen this review considerably. However, it is worth mentioning that the
KLEI Pure®Harmony RCA Plugs conveys a reproduction where the venue in many orchestral tracks appears as cavernous as the actual space it was recorded in, with a precise placement of musicians in the overall image and a clarity that completely exceeded my expectations from such a simple RCA upgrade.

And the Pricing?

A set of the
KLEI Pure®Harmony RCA Plugs cost around US$120 for a set of four, but the improvements made in my system on this one component was as significant as replacing the cartridge costing substantially more than that, making it an extremely attractive investment.

What do you do with the two remaining plugs? – you find an analogue buddy and you blow his mind as well.

KLE Innovations actually sell a six pack for AUD$185 – so you could convert your turntable and upgrade the RCA’s on the interconnect from the phono stage to the amp

I’m not really sure why they don’t offer two packs just for this purpose, particularly on this model – perhaps they will reconsider after reading this review


The most significant improvement the
KLEI Pure®Harmony RCA Plugs made for me was the reality that is now conveyed, which is one of those ethereal qualities that is so hard to measure and even more difficult to describe. It is also subject to our own experiences.
  • The greatly improved reproduction of venue acoustics from my system following this particular upgrade, often triggers memories of my own experience of playing in bands in many different locations, from small village halls, to nightclubs, to medium sized venues, each with their own very unique acoustic signature.

The Denon DL103 moving coil cartridge has been around for a very long time and at $229 it is a steal. There are a couple of minor warts and there are a few outfits than can modify this cartridge to get it to perform much much better. But before you opt to have the cantilever replaced, or have the cartridge “nuded” or have it mounted into an alloy or wooden head-shell, try this modification first. You will be amazed by the improvement in detail and you don’t have to wait the 6-9 weeks that the other options will take.

The 200 hours burn-in time appeared to me to be substantially shorter and I have not heard any improvements in performance since around the 60 hour mark. That may be due in part to the WBT high content (4%) silver solder I used, which I have found to perform extremely well when installing the
KLEI Pure®Harmony RCA Plugs onto my interconnects also.

If you consider implementing this tweak, I would also strongly recommend for the phono stage to amp connection, either the
KLEI Zero3 Interconnect , or better still the KLEI ®gZero6 Interconnect to compliment this change, since together, they will provide the best possible pathway from cartridge to amp you could possibly have.

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

  • the KLEI gZero6 Interconnect and Speaker Cable products

page6_blog_entry55-page6_blog_entry52-page6_blog_entry40-two-thumbs-up-2This is definitely a “MUST HAVE” for turntable arms having a one piece continuous loom!

KLEI Pure®Harmony RCA Plug Review

Over the last few weeks I’ve had a chance to become accustomed to the tonal qualities of the KLEI Silver®Harmony RCA Plugs that were installed on my Stager Silver Solids Interconnects for the KLEI Silver®Harmony RCA Plug Review, but those interconnects were now the pipeline from my Simaudio Moon LP 5.3 RS phono stage to my Naim 5i integrated amp, the source being a modified Denon DL103 cartridge attached to an Audiomods Classic tonearm having a one piece silver litz cable.

As such, I have come to appreciate their extraordinary abilities of these RCA connectors, which includes extremely fast response to not only very fast highs generated by percussive instruments such as cymbals and tambourines, but also their superb control of bass details such as those generated by pipe organs and synthesizers.

Also, the image that the
Silver®Harmony RCA Plugs convey is wide, deep and very precise. But perhaps the best quality of all - they are very “spacious”.

What do I actually mean by “spacious”? - In this case, it’s the ability to convey the space around the musicians and the subtle reflections of sounds from of their instruments within the recording venue.


KLEI Pure®Harmony RCA Plug represents the pinnacle of the KLE Innovations Harmony®Plug range of RCA connectors and as such, should provide the best performance.

Their appearance is almost identical to the
KLEI Copper®Harmony and KLEI Silver®Harmony RCA Plugs except for the mauve colour of the logo stamped on the collar. But inside, the centre pin and neutral pins are made of solid silver in accordance with KL’s Signal/Ground formula, giving them an IACS conductivity rating of 106%

But I still had to wonder, after becoming accustomed to the already exceptional performance of the KLEI Silver®Harmony RCA Plugs which, due too its solid silver neutral conductor and the extra thick silver plating on the copper centre pin, has the same 106% rating. Exactly what was left to improve upon?

Thanks to the guys at KLE Innovations, they had saved me considerable time by sending a set of
KLEI Pure®Harmony RCA Plug which had already undergone the 150-200 hours burn-in normally required from new, so that period of time had now been reduced to around 24 hours hours.

Whilst waiting for the RCA’s to arrive I had selected several albums from my collection of vinyl which I thought might best demonstrate the improvements the
KLEI Pure®Harmony RCA Plug should bring to the party.

Since KLE Innovations is located in the “Land of Aus” (Oz) (aka Australia), what better album to select than
Business as Usual by Men at Work. The sound engineering on this album is superb. Details, such as the high frequency edginess of the the Sax and the crispness of the drums and guitar work to the more subtle changes in the textures of the various bass lines on the various tracks made it a very good album for the evaluation.

In very simple terms…
Everything got bigger, faster and cleaner!

The bass line now had added detail and texture, the cymbals were crisper and fuller, the mids were warmer, the dynamics were faster and the image just seemed more complete. There was an added “punch” to both the percussion and also to the hammering of the very muted guitar strings. Lastly, the vocal detailing is now very clear and very well isolated within the recording.

Songs from the Wood, by Jethro Tull, an album from my long distant past, has always been a favourite. It features some of the best harmonized and multi tracked vocals ever put onto vinyl. It was these vocals that the KLEI Pure®Harmony RCA Plug seemed to perform minor miracles with micro details, in order to separate each vocal into a clearly audible presentation.

For me, spatial integrity, i.e. how accurately the artists and instruments are represented in the space of the recording venue, is best portrayed by classical recordings, since most are recorded using very few microphones, which translates to less manipulation of the final product.

To this end, one of the best albums is from a bunch of very anal sound engineers that record on the Tacet label.

How anal you ask?

  • Side Two on the album Das Mikrofon Vol.II, contains 24 tracks, each track using a different microphone!
  • Side One contains some nice Jazz Happy

But it was Das Mikrofon Vol.I that I had selected to determine just how good the Pure®Harmony RCA Plug was at conveying some very large venues.
  • Track One on Side Two is Toccata Terzza in A, one of my favourite pipe organ tracks that I also use to determine how just well bass frequencies are reproduced, since with pipe organ music there are extremely complex low frequency textures produced by those massive pipes.
  • Not only did the KLEI Pure®Harmony RCA Plug convey the cavernous nature of the venue, but they displayed extremely fine control across the entire range of pipes from the smallest high pitched pipes to the low frequency behemoths.

How many albums/tracks can I list where the
KLEI Pure®Harmony RCA Plug made me sit up and listen? Pretty much all of them.

There are a few tracks where the improvements were more subtle…
  • such as the whispery textures of Diana Krall’s voice on her tribute to Nat King Cole album All For You.
  • The distinctive sound of the slide of a bottleneck on guitar strings of Ry Cooder on his album Boomer’s Story

Then there were improvements that leapt off the vinyl - the all-out in your face dynamics on albums such as..
  • the incredible percussion detailing and synth work on James Newton Howard & Friends - by James Newton Howard
  • some really deep synth and piecing guitar work on Under the Joshua Tree by U2
  • the explosive “rifle-crack” drums and excellent synth work on Back In The Highlife from Steve Winwood
  • the crispness of the guitar work on the album But Seriously Folks from Joe Walsh
  • And if you are a fan of Led Zepplin’s - Whole Lotta Love - you’ve never heard it like this - incredible!


Well, as I said above, while waiting for the
KLEI Pure®Harmony RCA Plug I wondered just what improvements would they provide. Was it going to be a serious case of “diminishing returns”?

The improvements I witnessed between my identical interconnects, one se
t with the KLEI Silver®Harmony RCA Plug and the second with the Pure®Harmony RCA Plug was immediately noticeable. Improvements in dynamics, clarity, image and bass extension, with a new “fullness” to the reproduction and a new “reality” in the performance.

I’ve experimented with cables of several types over the years and used a variety of connectors, including the Eichmann Silver Bullet, which I had rated very highly.

Then Keith Louis Eichmann requested I try his new
KLEI Copper®Harmony RCA Plug which performed even better. The KLEI Silver ®Harmony RCA Plug again proved to be a significant improvement over the Copper®Harmony, but the level of performance the KLEI Pure®Harmony RCA Plug has achieved is the new benchmark in RCA connector performance.

Achieving this level of performance simply with an RCA connector may sound unbelievable, almost “magical” and in my mind, makes the team at KLE Innovations…

“The Wizards of Aus”

If you like to dabble with making your own interconnect cables, then the
KLEI Harmony®Plug range of products are designed to fit your budget and perform exceedingly well.

The one thing the KLEI Harmony®Plug range is not...


There is no gold or rhodium plating, no carbon fibre casing, no cryo treatment

If you are after looks - select another product


If you want a serious product capable of the ultimate in RCA performance….

  • KLEI Pure®Harmony : pure genius, pure performance, pure magic!

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

ADDENDUM: especially for Turntable Enthusiasts - also see UPDATE: Pure®Harmony RCA Plug Review

KLEI Silver®Harmony RCA Plug Review

Well, it seems like the guys at Keith Louis Eichmann Innovations liked my
KLEI Copper®Harmony RCA Plug Review so much, that they sent a pack of their new KLEI Silver®Harmony RCA plug, which is the middle entry in their KLEI Harmony®Plug line.

Visually, the only thing to distinguish between the KLEI Copper®Harmony and the KLEI Silver®Harmony is the colour of the logo on the collar, as can be seen below.


Since I found the performance of the KLEI Copper®Harmony RCA Plug to be so good, I asked the question:
  • what would make the consumer opt for the more expensive KLEI Silver®Harmony RCA Plug?

The KLEI response:
KLEI™Copper Harmony plug
  • Proprietary mathematical modelling optimises mass, thickness, and composition of the conductive pins to enhance electron flow, incorporated in accordance with KL’s proprietary Copper Signal/Ground formula, where extrapolated results are even >102% IACS.
  • The conductive pins incorporate highly conductive materials, such as copper and silver.
KLEI™Silver Harmony plug
  • Proprietary mathematical modelling optimises mass, thickness, and composition of the conductive pins to enhance electron flow, incorporated in accordance with KL’s proprietary Silver Signal/Ground formula, where extrapolated results are even >105% IACS.
  • The conductive pins incorporate highly conductive materials, such as copper and silver.

What is IACS again ?
— it’s a measure of the conductivity of various metals relative to “Pure Copper”, a standard developed for copper wire producers, having a rating of 100%

- See
IACS Conductivity Ratings PDF for further details.

When I asked what performance improvements to expect from the Silver®Harmony, the KLEI response was:

  • They bring out even more of the details, dynamics and improved imaging obtained using the KLWI Copper®Harmony.
Now the KLEI Copper®Harmony had performed well above my expectations, improving on my original Eichman Silver Bullet RCA’s by a considerable margin and taking their place as my new reference standard, but were the KLEI Silver®Harmony RCA’s capable of repeating that level of performance improvement?

The Prep Work...
In preparation for this review I had taken KLEI at their word, that the KLEI Silver®Harmony would reveal more dynamics and details. So, whilst waiting for their arrival I decided that in order to perceive such benefits I might need to do a couple of things
  1. Upgrade the power cables on the source components and amplifier - a little extreme you think? Well, I was in the process of completing this when I received the first email from KLEI asking me to review the KLEI Copper®Harmony, so that was put on the back burner until the review was complete.
  2. Find some additional tracks that I thought might just reveal the performance improvements mentioned above

Thankfully, the KLEI Silver®Harmony took a little while to arrive, which gave me ample time to install and burn-in the new power cables, get accustomed to the new sound and select a few tracks that sounded that they might provide the required details and dynamics.

During this process it became quite apparent just how good the KLEI Copper®Harmony really are: their delivery of exquisite detailing, spacious imaging and very fast dynamic response was clearly audible in my system.

SIDEBAR: Some Third Party Feedback...
During the time the KLEi Silver®Harmony were in transit, I had the opportunity to exchange experiences with another person that had tried them.

Their initial findings (i.e. before complete burn-in) were completely different to my own experience with the KLEI Copper®Harmony, in that they thought the KLEI Silver®Harmony sounded “boring” which I took as “lacked in dynamics”, the upper frequencies appeared to “roll-off” very quickly and they did not experience the blooming of bass frequencies as I had.
  • I believe this is a good indication that the effects a person encounters during burn-in will vary when used on different cables.
  • They did confirm that after a longer burn-in period (100+ hours), the KLEI Silver®Harmony had outperformed the KLEI Copper®Harmony, citing better image, dynamics and details.

Cut To The Chase…
Well - the proof of the pudding is, as they say,
“in the eating”.

So once they arrived, I installed the KLEI Silver®Harmony onto one set of my Stager Silver Solid interconnects and started the burn-in process.

As with the KLEI Copper®Harmony, I allowed for approximately 150 hours burn-in time, with small mini-auditions performed at approximately 24 hour intervals.

What I experienced within the first hour was almost identical to what I had experienced with the KLEI Copper®Harmony:
  • Immediately, I notice a significant improvement in imaging and dynamics
  • mid-frequency details were initially very good - about on par with the KLEI Copper®Harmony after burn-in
  • high frequency details were much improved and extended
  • Again, there was a significant “blooming” of certain upper-bass frequencies
  • there was a new depth to the bass frequencies that was also very muddled and bordering on distorted

Just as with the KLEI Copper®Harmony, the character of the KLEI Silver®Harmony changed significantly for the better as burn-in progressed
  • On Eric Clapton’s album Clapton Unplugged, the stomping of his foot on stage started out even more nauseating, due to the extended depth to the lower bass frequencies. But just as before, after burn-in the bloating simply melded into the background and became an integral part a very good live album, which also displayed even more details, especially in the vocals. On tracks Running on Faith and Walkin’ Blues, where, thanks to the extended upper frequencies, the use of the bottleneck throughout the track is perhaps the most realistic reproduction I have ever heard.

  • On the track You Look Good To Me from the album We Get Requests by The Oscar Peterson Trio, not only could I hear Ray Brown humming his intro, but there was a significant improvement in the details, such as the vibrations the strings make against the fingerboard of the bass, which previously was quite muted and now the superb textures in the triangle at the beginning of the track were very audible.

  • The Cymbal work on Staple It Together, from the Jack Johnson album In Between Dreams had a much faster attack from the initial strike and the decay was longer than that experienced with the KLEI Copper®Harmony.

To challenge the dynamic presentation I selected some new tracks that I thought would be more revealing that those I had selected for the KLEI Copper®Harmony.

The first was
Precious, from the album Diva by Annie Lennox
  • Annie’s voice has a superb “brittleness” to it and the KLEI Silver®Harmony provided the edge required to highlight that trait.
  • The base line had a deeper presentation, but also an extended level of control that brought out never before heard texture and the improved dynamics gave the track some additional slam not perviously experienced.
  • The improved detailing also made the opening chord sequence on the electronic keyboard much more revealing of the textures that had been recorded.

Another track that made me sit up an listen was
Turtle Shoes, from the album Don’t Worry Be Happy by Bobby McFerrin.
  • For those of you unfamiliar with his work, Bobby McFerrin multi-tracks pretty much all the vocals himself, with some amazing sound engineering that captures his percussion line which is derived from him pounding and slapping on various body parts - he also has a very edgy vocal when deemed necessary and again KLEI Silver®Harmony allows those extremely fine details to be heard.
  • There is depth to the percussion line that is extremely textured, but since the focus is very much on the vocal performance you are also able to hear every delicate nuance of this talented performers considerable vocal talents.

From the album
The Police - Greatest Hits album I had selected Walking On The Moon
  • Primarily because I thought that the opening quitar chords would highlight the KLEI Silver®Harmony’s dynamic prowess and I was not wrong.
  • But better still, the details in Sting’s voice and the textures in his bass line reinforces the amazing abilities of this diminutive little RCA plug.

I’ve used words like “edgy” and “brittleness” to describe how the KLEI Silver®Harmony enhances micro details and combines its extremely fast dynamic abilities to reproduce those traits.

But initially, I had wondered if this new edginess was due to distortions that had not
“worked themselves out” during burn-in.
  • To verify that this was NOT the case, I returned to a track previously used in the Copper®Harmony review, the Violin Concerto no. 4 in D major KV 218 - Allegro by Marianne Thorsen / Trondheim Solistene.
  • If there were distortions in the signal, then the violin on this track would likely reveal them.
  • Instead, the violin came across smooth and extremely detailed with a more spacious image that is wider, deeper and with a more precise placement of the musicians within the space.
  • What you hear more of are the extremely fine higher frequency micro details, such as those found in the reproduction of cymbals, having a very fast attack of the initial strike, followed by a long decay, both of which has body and texture.
  • Sibilance now has considerably more texture and depth and is silky smooth.
  • The sound the KLEI Silver®Harmony conveys is full bodied and full range and is definitely NOT “thin” or “bright”.

Thinking back to the KLEI Copper®Harmony review, a track that I believed would demonstrate how much more revealing these RCA plugs are is
Iberia: Debussy - 3rd Mov’t - London Symphony, Andre Previn conductor.
  • The first thing I noticed was the extended width of the image, now considerably wider than the distance between the speakers.
  • There is without a doubt more details, particularly from the percussion section that is placed even further back in the image, but without loosing any clarity or volume.
  • The tambourine had much more pace to it and the castanets had a more life-like “clack” to them

One of my favourite newly selected review tracks is
With You In Mind from the album Blue Chip, by Acoustic Alchemy, selected because of the extraordinary sound engineering and musicianship. It’s a very easy track to listen to because there is not a cacophony of instruments vying for your attention and distracting you from the details.
  • Just a couple of guitars, a little subdued percussion and some nice melodic slide guitar way in the background. And that’s where the KLEI Silver®Harmony’s excelled, delivering a crystal clear reproduction containing the very subtle micro details of the strings being plucked and the buzzing of the strings on the fretboard and as their hands move up and down the neck the unmistakable rasping of fingers sliding over the “round-wound” strings.
  • Perhaps my playing guitars for many years has made my ears more “receptive” to these sounds, but it still takes a very adept system to reproduce them with such startling realism and clarity, which left me believing the KLEI Silver®Harmony has without a doubt made a significant contribution to my systems performance improvements.

At the other end of the frequency range is added depth in the lower bass frequencies with considerably more control. This was very evident on
Más, from the album Mi Plan by Nellie Furtado, which has some of the deepest synth work in my collection and another track from the same album, Vacación, where the thump of the bass drum is very deep and superbly controlled. In fact, the entire album highlights the amazing dexterity of the KLEI Silver®Harmony

My observations above were made while using the Interconnect to connect the analogue outputs from my DAC to my Amp. I then used the exact same interconnect to connect my phono stage to the amp and listened to several tracks from multiple albums.

To my surprise I found that there were even bigger improvements in image, dynamics and details. It seems that the KLEI Silver®Harmony are an even better match for my phono stage than the KLEI Copper®Harmony.

I have not found any downside in using the KLEI Silver®Harmony on my Stager Silver Solids Interconnects, other than a slightly longer burn-in period that approached 185 hours to reach their full potential. Across the board they perform exceptionally well, providing an image on orchestral tracks that is so deep that a little additional volume is required on some older recordings that were performed in very large venues.

The response from KLEI posted above was spot on - more of everything, but in a very balanced presentation that does not accentuate any part of the audible bandwidth.

In the case of the
KLEI Copper®Harmony I summed up their performance in one word - Clarity

With the KLEI Silver®Harmony, especially on acoustic tracks and classical ensemble tracks, it is like being at a live performance.
  • On live albums the applause has body, instead of sounding like a game show contestant getting the right answer.
  • When Eric Clapton talks between songs you just had to close your eyes and he was right there in the room.

A technique I often use to gauge how well my “tweaks” or “upgrades” are performing, is to stand or move around in the hallway outside my listening room.
  • Why? - it removes distractions such as “spatial image” from the equation and allows me focus solely on the acoustic attributes of the sound
  • I find the timbre of an instrument or the subtleties in an artists voice to be much more revealing and allows the realism in the recording shine.

In the case of the
KLEI Silver®Harmony they transcend clarity - they are simply - Transparent

The transparency of the KLEI Silver®Harmony makes them the closest thing to “3D glasses” for two channel audio I have experienced to date.

That is - until I review the
KLEI Pure®Harmony - stay tuned - coming soon Happy

The price of the Silver®Harmony? - $90 for a set of 4 (from Parts Connexion)

The details on the
Silver®Harmony, including Australian pricing, is available on their web site at...

They are also available in North America from
Parts Connexion


Ever get that
“smile of satisfaction when something very right is happening” ? - ME TOO! Happy

The KLEI Silver®Harmony RCA, when used with high performance interconnect cable, conveys an incredibly detailed analogue signal that results in a very realistic three dimensional reproduction of recorded music, regardless of whether it originates from an Analogue or Digital source.

One question that came up recently - Can the KLEI Harmony®RCA Plug range be used for Digital interconnects?

  • I have not tried them as yet, but plan on doing so soon.
  • I have read a review that cites exceptional performance improvements over one very expensive purpose built single ended digital cable.
  • I have also exchanged several emails with KLEI on this topic and it appears that due to the high impedance of the entire KLEI Harmony®RCA Plug range (i.e. >110 ohms), they do not degrade the transfer of a digital signal between components.
  • This however, can be a problem with the more conventional RCA designs, where, if not matched exactly to the impedance of the cable, can result in internal distortions and jitter, causing poor sound quality.

Until I actually try them, I can only offer an “opinion”, but having experienced the speed and dexterity of their analogue performance I would have to conclude that the KLEI Copper®Harmony or KLEI Silver®Harmony, when used for digital interconnects utilizing 50, 75, or 110 ohm cable, may well result in the near elimination of jitter caused specifically by interconnect-component interaction and component transmission & reception issues, resulting in a significant improvement in the analogue performance of most current day DAC designs.

In some quality digital products, performance may even transcend the
"digital realm" and possibly achieve the much sought after "soul of analogue".

And YES - the KLEI Silver®Harmony are my new reference RCA connector!

But it’s not farewell to the KLEI Copper®Harmony just yet - I’ll try them on a very good digital interconnect I have - so check back in a couple of weeks Happy

UPDATE: As planned, I transferred the KLEI Copper®Harmony to one cable in a pair of “The NAME”, a 75 ohm interconnect from Van den Hul.

Removing the existing RCA’s from “The NAME” revealed that they were in fact very well made RCA’s that appeared to have been matched ,from an impedance perspective, to that of the cable. Not that I can tell that for certain, but the construction approach appeared very similar to that of quality BNC connectors.

Attaching the KLEI Copper®Harmony to the much thicker centre conductor and the braided shield of of the 75 Ohm cable was a little more difficult than my 24 gauge solid silver interconnects, but much easier than the Silver Bullets and once the housing was in place and the small set screws were tightened onto the 7.3mm diameter cable it provided very good support.

To test the cable I reinstated my Pioneer Elite DV-45A DVD player with SACD capability, Unfortunately SACD playback is only available via the players analogue outputs, so the de facto digital standard for the purpose of this review was going to be the 16/44kHz digital stream via it’s s/pdif output, which in turn was connected to my Schiit Bifrost DAC

However I was able to easily perform an A/B comparison with the exact same tracks within my iTunes library on my iMac that is connected to the same Schiit Bifrost DAC via its USB-2 asynchronous interface. My iMac also uses Audirvana for final digital transfer to the DAC, in order to bypass the vastly inferior Apple audio routines that alter the digital content before transmission. So the “data” being transferred is what resides in the actual music file - nothing added!

Several tracks of varying musical styles were auditioned, several times each in fact and I can report that I could not tell any difference between
  • the digital stream from the DVD player’s s/pdif output using the Van den Hul “The NAME” interconnect with the KLEI Copper®Harmony RCA’s
  • the digital stream from the iMac via iTunes/Audirvana using a USB digital link.

I did also manage to play some music DVD’s that contain 24/96kHz tracks, but alas the DV-45A down samples to 16/48kHz, so that was the best sample rate I was able to test with.

There were no signs of jitter, and playback was very smooth, spacious, detailed and dynamic, which supports the claims of KLE Innovations, that the KLEI Copper®Harmony and KLEI Silver®Harmony are also very capable performers when used on digital interconnects.

I did switch over to the other Van den Hul interconnect that is terminated with VDH’s own RCA’s and by comparison. There was a very slight degradation in high frequency details, most noticeable in the smoothness of the presentation of cymbals and sibilance.

One reviewer, with a digital front end capable of higher sample rates than my own, was very surprised to find that a cable he constructed himself using the KLEI Harmony®RCA plug, performed better than a very expensive interconnect he owned.

So, if you find your digital components are not performing to your satisfaction, give the Harmony®RCA plugs a try.

You might be pleasantly surprised.

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

KLEI Copper®Harmony RCA Plug Review

To date, all of the reviews on this blog (i.e., prior to this one) pertain to products I have personally acquired and found to be exceptional performers.

Since I am not a
“professional reviewer”, I was very surprised to find and email in my inbox one day, requesting my participation in a review of a brand new product from a company called Keith Louis Eichmann Innovations.

The product is their KLEI Copper®Harmony RCA Plug, which is the entry level product in a family of high resolution RCA connectors, the others being the KLEI Silver®Harmony RCA Plug and the KLEI Pure®Harmony RCA Plug (more on those later)

So what is so special about
this RCA plug?

Copper 2

Well, its body is constructed from a very high melting point polymer, with a silver coated copper centre pin and in place of the large metal barrel found inside the outer housing on most “conventionally designed” RCA plugs, there is a smaller polymer collar with a small silver plated copper conductor imbedded into the inside of the outer collar (see photo below) to provide the contact point for the neutral connection.

The neutral pin also extends upwards from the collar such that, when used with the
optional metal housing, it serves as a grounding point.

NOTE: For this review, the KLEI Copper®Harmony RCA Plug used had the standard polymer housing.

Copper 1

Now this is not my first encounter with this style of RCA plug, since I currently have the
Silver Bullet RCA attached to the source end of the Stager Silver Solids interconnects that connect my Schiit Bifrost DAC and my Simaudio MOON LP5.3RS Phono Stage to my Naim 5i Integrated Amplifier, which employs silver plated Neutrik DIN Connectors.

Having used the Silver Bullet RCA’s for the last 10 months and being very satisfied with the details and dynamics they provided, I was very curious as to how much improvement an RCA plug utilizing very similar design principles (i.e., from a visual perspective) could bring to my system.

One thing for sure, connecting the KLEI Copper®Harmony to the solid silver interconnect conductors was very easy for two reasons:

1. The centre pin connection is offset to the opposite side from the neutral pin, making both leads very easy to connect.

  • Far better than any of the conventional style of RCA plugs I have used in the past.
2. The very high melting point polymer used allowed the pins to be heated up sufficiently to allow a very good solder joint, without melting into a puddle of plastic goop.

Once you remove the housing, one other thing that stands out about this RCA is the lack of any kind of cable strain relief support that is generally part of the barrel of most other RCA designs. But in this design, strain relief is actually provided for in the design of the housing of the RCA plug, which has two hex screws, that can be tightened onto the cable, eliminating stress on the solder joints.

NOTE: The maximum size of cable that can be accommodated is 9 mm.

In my case, the Stager Silver Solids conductor is quite thin compared to shielded types of cable, so I elected to construct a strain relief sleeve around the cable, which was adequately supported by the housing and set screws.

KLE Innovations are quite aware of the use of small diameter cables, so they supply with each plug a small end cap especially designed for small gauge cables e.g. such as those used on the very fine wiring harnesses for turntable tone-arms.

Cut To The Chase Please

So with the KLEI Copper®Harmony RCA’s in place, I connected the cables and started the “burn-in” process.

Since the cables were well used and due to the very small amount of metal used in the RCA, I had reasoned that the period of time required for complete burn-in would be less than other designs, but just to make sure, I had planned for around 150 hours, during which time I auditioned their progress several times.

My initial impression (i.e., within the first hour of listening) was that somehow, the team at KLE Innovations had discovered some magical metallurgical process in which electrons had been freed from their earthly bonds and allowed to proceed at faster than light speed to their final destination — not that my previous RCA’s are slow by any means — the KLEI Copper®Harmony RCA’s are just that much quicker!

The details had significantly improved, together with a noticeable improvement in dynamics and a deeper more spacious 3D image

And it was only going to better?

Well, there was a period of time at around 75 hours where something went a little “wobbly” - I can’t think of a technical term for it Happy
  • There was a definite change to the presentation of bass frequencies that had many tracks sounding unnaturally bloated.
  • On Eric Clapton’s album Clapton Unplugged, the stomping of his foot on stage became almost nauseating.
  • Several R & B tracks were skipped over because their bass was just too overpowering.

Fortunately, 24 hours later that particular phenomenon had abated completely and the bass had changed to a more deeper and far more detailed rendition, that appeared to be much more complete and natural, resulting in more realism.

And Eric’s loud foot tapping? — That was now just an integral part of the concert — thank goodness!

Now that the burn-in period is complete, the entire image has transformed into one having a very precise placement of instruments and artists each surrounded by their own individual venue specific (or well intentioned engineer inspired) signatures with a very dynamic presentation.

One very good example of that is on the Oscar Peterson Trio album
We Get Requests. The track You Look Good To Me starts with Ray Brown bowing his double bass and then continues with a bass lead-in, during which you can hear him humming the notes he is playing in the background. It was as if I had been transported into the recording venue — listening to it live — simply superb.

The Dynamics are now presenting a far more realistic presentation also...
  • Initially, the most noticeable improvement in dynamics were with drums, where rim shots has the immediacy of small calibre gunfire and bass drums seemed to punch through the air like a canon.
  • Electric bass also had significantly more slam to it and electric guitar chords were extremely crisp.
  • As burn in progressed the more subtle textural details of these instruments became more vivid, but the dynamics of their presentation remained unchanged.

The music had more body and was simply more complete!

On the upper end of the frequency range the most noticeable improvements in detail and dynamics were conveyed by instruments such as Cymbals, Triangles and Tambourines...
  • The initial attack of these instruments is now very crisp.
  • The decay of Cymbals and Triangles have extended significantly beyond their previous fall-off point due to the micro details now being revealed.
  • and again there was the delightful addition of texture that was previously missing, especially with Tambourines.
One of my favourite tracks for presenting some very natural sounding Cymbal work is on Staple It Together, from the Jack Johnson album In Between Dreams.

Also, on his album On & On, the crisp guitar work and the subdued bass line on Wasting Time, is dropped into a spacious image constructed by nicely applied reverb around the drum work.

Vocals also benefit significantly, in that the discernible vocal textures now have more clarity...
  • One of my all-time favourites, Diana Krall has revealed a whole new level of “s-e-x-y” with a smooth sibilance presentation and clearly audible textures in every whispery breath — the result is outstanding!
  • The reproduction of the raspy vocal tones of Xiomara Lougart on La Habana Joven is another testament to their ability to transfer micro details in a very dynamic manner.
  • Christy Baron’s whispery rendition of Ain’t No Sunshine, with a solitary bass for accompaniment draws you right into the recording.

And last but not least, the cavernous venues of classical recordings are reproduced with breathtaking reality…
  • One such recording is Iberia: Debussy - 3rd Mov’t - London Symphony, Andre Previn conductor that is presented with amazing clarity in the midst of a dizzying array of instruments that can now be clearly heard and located precisely within the image.
  • One of my favourite instruments is the Pipe organ, mainly for its many textures. The track Undring from the album HarmOrgan by Sigmund Groven & Iver Kleive is an excellent example of the depth of the sound stage that can be reproduced using these RCA’s - definitely cavernous!
  • One thing that did come to light with many orchestral tracks was the forward projection of the venue related acoustics to the point where they envelope the listener, but leaving the orchestra in the space behind the speakers — very engaging.
  • The reproduction of the Cello has improved significantly, allowing their very distinct and individual timbres to be distinguished
  • The upper frequency range of violins has actually become much smoother — the Violin Concerto no. 4 in D major KV 218 - Allegro by Marianne Thorsen / TrondheimSolistene is one such recording that highlights this particular capability of these RCA’s extremely well.

I’ve used many words that describes what the Copper®Harmony RCA Plug brings to the party...
  • Dynamic
  • Detailed
  • Cavernous
  • Engaging

But I think if I had to describe its outstanding performance in one word — it would have to be Clarity!

I cannot recall my modestly priced hi-fi ever reproducing music with such clarity.

Every instrument, every artist, every venue, every album, is being reproduced in a manner that would normally be attributed to spending thousands of dollars on significantly better components — not a $60 set of RCA plugs!

Even my oldest recordings are revealing details I’ve never before heard.

There is also a warmth that was previously missing, which is especially nice for digital playback, creating a more engaging rendition, with what appears to be a much larger “sweet spot” as a bonus.

So, just to make sure I was not hearing what my inner-self may have wanted my ears to hear - I switched to a second interconnect that is identical in every respect, except that it has the Silver Bullet RCA’s on the source end.

The Result…
  • Noticeably Flatter and thinner sounding
  • Less pace to the musical presentation
  • A little more vague
  • A little more muddied
  • Definitely less engaging

Don’t get me wrong, the old RCA’s are much better than the more
conventional RCA designs I’ve previously used.

But there’s a new guy in town — the KLEI Copper®Harmony RCA from KLE Innovations

Needless to say, the KLEI Copper®Harmony RCA’s are now my new RCA point of reference.

So Let’s talk Techie…

So how did the guys at KLE Innovations achieve such improvements?

Well, that’s proprietary and their gonna keep it that way, but they did share that they have a proprietary formula, i.e.,
KL’s Signal/Ground formula , which I believe (and I’m speculating here) specifies for each of their RCA plugs, design features like:
  • the metals used for the pins
  • the plating used for the pins and its density
  • the physical design of the pins

As an example of this, the KLEI Copper®Harmony RCA has high purity copper pins (IACS 101%) that are coated with a direct dense proprietary high purity hard silver plating (IACS 106%) — the rest they wouldn’t share — sorry Sad

What is IACS? — it’s a measure of the conductivity of various metals relative to “Pure Copper”, a standard developed for copper wire producers, having a rating of 100%

- See
IACS Conductivity Ratings PDF for further details.

I was sent significant literature so here is an extract from their Harmony RCA White Paper, highlighting some of the design features


The rest of the information, including Australian pricing, is available on their web site at:

They are also available in North America from
Parts Connexion

And Then There's...

KLEI Silver®Harmony RCA Plug and the KLEI Pure®Harmony RCA Plug.

What are their benefits? — Well, because I have not tried them as yet, I can only make comment, based on my communications from KLE Innovations.

To paraphrase: They bring out even more of the details, dynamics and improved imaging obtained using the Copper®Harmony.

Details and pricing of the
KLEI Silver®Harmony RCA Plug and KLEI Pure®Harmony RCA Plug is yet to be announced.

Future plans: KLE Innovations future plans include KLEI XLRs, Spades, Bananas, Binding Posts, RCA Sockets, Resonance Devices etc…(but not necessarily in that order)


Oh come on — after all that! — do ya really need one? - OK...

Well, without even taking into consideration their very competitive pricing, especially when compared to some of the much more expensive competition that exists out there, and simply based on their superb level of performance, I believe the KLEI Copper®Harmony RCA offers...

One of
the best “value for money” products in hi-fl today!

So go out and buy them!

UPDATE: the KLEI Silver®Harmony RCA Plug is now installed and going through the burn-in process as I type this - so keep an eye on this blog for updates Happy

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

RCA, XLR or DIN Connectors - Which is Best?

Please note: this post is an introduction only and does not cover everything pertaining to this subject, which can get very complex.

Before looking at the actual performance of these connectors I must first explain that RCA can only support a “single ended” electrical interface, DIN typically supports a single ended electrical interface and XLR typically supports a “balanced” interface.

A Single Ended Interface:
  • has a conductor for the signal and
  • a second conductor for the neutral (or ground)
  • with a “Coax cable” the shield performs double duty as the neutral conductor
  • A “balanced cable” having two identical conductors + shield can also be used for single ended cables
  • an RCA connector will carry the signal for the left or right channel only
  • a DIN connector can carry both left and right channels

A Balanced Interface:
  • has a conductor for the signal - referred to as "+", or "non-inverted",
  • a second identical conductor for an inverted copy of the signal - referred to as “-“, or "inverted"
  • a conductor for the neutral (or ground)
  • an XLR connector will carry the signal for the left or right channel only
  • the neutral or ground is not used for signal transfer - so ground loop hums are eliminated

What does Balanced buy me?
When the balanced signals are processed at the receiving component (e.g. the amp) they are combined by a process referred to as “subtraction”, which effectively
retrieves the original signal.

The subtraction process however has a couple of additional benefits:
  • it effectively doubles the strength of the signal, which allows for much longer cable runs to be used, and
  • cancels out any hum or noise picked up by the cables themselves

Alas - the circuitry in balanced components is more complex and in turn more expensive to manufacture.

There is also the possibility that the circuitry in the sending component is not perfectly matched in the receiving component - which can result in performance that is in fact lower quality than a single ended approach

So what are the actual connector differences - the obvious...
  • only has the ability to connect two conductors - a signal and a neutral/ground
  • originally used with Coax type cables - one centre conductor and a shield conductor
  • RF Noise will flow through the neutral side of the circuit
  • the barrel (i.e. the neutral side) is generally made from materials having a lower IACS conductivity rating, hence does not perform as well
  • use on cables longer than 30 ft can affect performance
  • has the ability to connect three conductors - signal, inverted signal and ground
  • generally used with "balanced cables" that have two centre conductors of the same gauge and a separate shield conductor
  • RF Noise is generally contained in completely separate shield/ground circuit
  • the pins are generally made from pure copper - with a superior IACS conductivity rating
  • can be used on cables longer that 30ft without an issue
  • is normally used in single ended designs
  • because it uses very small pins, then materials that have a high IACS conductivity rating are often used while keeping costs low
  • performance is better than many RCA connector designs

What is IACS? — it’s a measure of the conductivity of various metals relative to “Pure Copper”, a standard developed for copper wire producers, having a rating of 100%

- See
IACS Conductivity Ratings PDF for further details.

Have XLR connectors been used on components using a single ended design?
  • There are companies that have used XLR connectors on their components utilizing a single ended design
  • The manufacturer adapts the internal wiring such that it does not present a problem when connecting to components using balanced circuits

Can you connect a balanced output to a single ended input?
  • Yes, but you should only connect the non-inverted signal pin on the XLR to the signal pin on the RCA
  • you may experience additional noise and/or possibly a lower output level

Can you connect a single ended output to a balanced input?
  • NOT directly!
  • A conversion circuit would be required.

XLR's have always been a better "quality" connector that uses plated copper for the pins. But it has more component parts, resulting in it being more expensive to manufacture. Whereas RCA connectors were generally made from more "cost effective" materials like brass and far less complicated to manufacture.

Having said that there are many RCA connectors that are very highly priced - some, for no apparent reason.

A Better RCA Interconect...
To elevate the performance of interconnects using RCA connectors, i.e. from a noise perspective, in place of using a a coax cable, you can use a balanced cable (two identical centre conductors + shield) by connecting the two centre conductors to the signal and neutral, but connecting the shield to the neutral side of the RCA at only one end of the cable.
  • This end would always be connected to the component that was the origin, or source of the signal.
  • Provided that component was correctly grounded, any noise in the shield is not conveyed to the next level of amplification in the chain
  • This technique is called “floating shield” and it brought a very respectable level of performance back to the RCA connector

But there remains a serious problem with the RCA in that pure copper, because of it’s softness, is difficult to machine. Copper alloys were developed, but even those fall below the conductivity of pure copper, or even silver.

A Better RCA Connector...
KLE Innovations, had the foresight to develop a quality RCA connector that did not require the same manufacturing processes that in turn allowed pure copper and silver to be used. There is also more to the science of these connectors in that they focus the transmission of the electron flow resulting in a much improved transmission of the electrical signal and minimize electrical reactance within the RCA itself, resulting in improved dynamics, details and spacial image.

The performance of many RCA interconnect cables are now comparable to XLR interconnects

Because of the improved performance of high quality RCA interconnects and the development of the floating shield approach, the choice of which type of interconnect to use on components that have both types of connector implemented is not quite so clear cut these days, i.e. for shorter cable lengths.

So which interconnect type do you buy?
  • The obvious - If you have two components that have both types of connector - Buy XLR!
  • But you no longer need to limit you component choice to only those components with XLR connectors only
    • XLR to RCA cables are also available

So right about now you may be thinking that perhaps to move to the "next level" in performance you have to sell off all your RCA connected components and buy only those components with XLR Connectors!

Well, you can implement floating shield grounding strategy using interconnects with RCA connectors and balanced cables that will deal very effectively with RF interference in a system.

If you utilize the "Floating Shield" design for interconnects and power cables - and implement the component grounding strategy identified in
Hi-Fi & Grounding - the effectiveness at removing RF interference from the next level of amplification is second only to that of systems where every component adopts a balanced design.

Most RCA Interconnects are NOT constructed using floating shield techniques. Those that do will indicate this fact
by a ground-end marking sticker on the actual cable (e.g. Van Den Hul cables are marked in this manner) - this end ALWAYS connects to the source component

CAUTION: I have seen interconnects out there that have a little arrow indicating a "direction" - this is NOT always an indication that the cable has a floating shield, but more often indicates the direction in which the wire was extruded. Always ensure that both left and right channel cables are connected in the same direction.

UPDATE: since writing the original posting, I now use my own DIY interconnects

DIY Interconnect Cables - The "Helix Mark V"

These utilize an advanced helix architecture and can resolve to an extremely high level due to the materials used and their unconventional cable geometery.