KLE RCA plugs are the real deal!!

I ordered a set of KLE RCA Pure Harmony plugs to use for a pair of interconnects using Duelund 16ga wire. I previously built a set, with good results, using standard switchcraft plugs. The difference, even without break in, was staggering. Although the Switchcraft plugs sounded good themselves alone, however, when doing a direct comparison to the KLE's, the difference is clear. The cables using the SC plugs sounded harsher (especially on high end) when compared to the KLE. The cables seem to have a "free-er"(FLOABT) sound or more flow. Seemed as if the SC's were holding something back. 

As far as building the cables, the separated solder posts make things way easier. Everything is quite compact (especially for larger wires) in the SC plugs. The removable grommets are a nice feature if one wants to use thicker cable wraps, shrink tubing or shielding. 

One other area I think the KLE's are great for is trying wire combinations without soldering. With the "V" shaped solder posts, one could "wrap" the ends somewhat snug and use the wire locking screws. You would still have to be very delicate when hooking up...however this is something that is pretty much impossible with the SC's. 

As I plan to build my entire system's cables, KLE will be the plugs I use on everything. I highly recommend
I just made a set of ICs with the Pure Harmony connectors as well. After connecting the cables to RCA jacks about two times, the silver plating on the negative contact wore completely off on two out of the four connectors! It may have come off after one connection (I did not look at the negative contact closely until I was ready to permanently put the cable in my system).  I can now see the copper that is below the silver. And yes, the RCA jacks were cleaned/deoxidized and in perfect condition before connection.
I do not recommend not soldering. There is no way to secure the wire around the v-shaped terminal. I actually do not like the terminals on these. A terminal with a hole in it would be much more user friendly and let you create a good mechanical connection before soldering.
I was hoping to find something good here because the bullet style RCA's on my Origin Live arm are after several years giving me noise problems. But sadly the KLE's are the same poor design.

Its not just me by the way. Talking it over with Keith Herron he said the same thing, bullet RCA's can be a problem.

Might still be worth a try but then I looked at the price. RU serious?

I know a guy who for decades- at least 30 years- has been building all his own cables. Thirty years. Never once made one even half as good as what you could buy from Synergistic Research for less than the cost of these KLE plugs.

I guess people who build their own cables must just really be into tinkering?
Wow...sorry to hear about the issues. I was not suggesting NOT to solder. Just if you want to try experimenting with different wires to try out before actually doing a solder, the KLE's seem like a great way to do it.
The mid to lower end Synergistic research cables are typical of many brands. many say nothing special, some love them. I researched them a couple years back. I may have to give them a try sometime

I guess I feel that soldering is so easy you might as well do it even if it’s temporary.

Please check your negative contacts closely after you connect them to RCA jacks a couple of times. You will need good lighting and a magnifying glass if you don’t have really good vision, but it’s easy to see if the silver plating has worn off if you look for it. Honestly I’m not too worried about it. I can’t imagine that the sound of the cable will change in the absence of the incredibly thin coating of silver on that tiny contact. The fact that it wore off so quickly does indicate that they are pretty poorly made, though. I’m not happy about that, especially considering that a set is $60 something bucks.
These are easy to solder and hold up just fine. Just need the right technique. The thin coating will mark superficially easily but is a complete non issue. These are excellent low mass bullet plugs that make great shielded and unshielded RCA cables. They sound wonderful and just get out of the way with no editorializing.  Seems no product will please all, but it helps to know how to work with these. 

it helps to know how to work with these.

It has absolutely nothing to do with not knowing how to work with them. Simply pushing the connector onto an RCA jack two times COMPLETELY REMOVED the silver coating on the negative contacts. It is not just a "superficial mark" as you say. The silver coating, which KLEI puts on for a reason, is no longer there and able to do it’s job, whatever KLEI believes it may be.

These are easy to solder and hold up just fine.

I agree that they are easy to solder, but a nice mechanical connection prior to soldering is impossible due to the stupid v-shaped tab. A hole in the tab would be 100 times better than a "V". The "V" just makes no sense. These connectors do not hold up just fine as explained above. Why don’t you add a dealer disclaimer to your posts in threads like these? I know building cables is just a hobby for you, but it seems fair.
I accord with grannyring.  I've made ICs with these and can confirm that they sound great and hold up after many reinsertions.  For a solderless connection, the more expensive Bocchino RCAs are preferable, but with KLE it is still possible to make clean semi-solderless terminations by tacking a bit of solder at one end, tightly wrapping the fork with a few turns of bare wire, and tack at the end with solder.  To improve conductivity of the bare wire-wrapped section and block out oxidation, cover the wrap with a sealing coat of Perfect Path Total Contact graphene paste.  This cures to a hardshell finish.  
Agreed on the Total Contact paste.  Amazing stuff! Glad to see you are onto this wonderful tweak. 
I will assume that I got a defective set of connectors if at least five people actually remove their cables and closely inspect the negative contact for wear.  You need to look for it.  If you do not look for it with bright light and a magnifying glass like I said earlier, you will never know the coating has rubbed off.  That contact is tiny!  So LOOK for it.

So, if everyone can inspect all four connectors on a set it ICs, let us know how many times they have been inserted, and which connector you have (Classic, Copper, Silver, Pure, or Absolute), it would be helpful.  Until that happens, you need to assume that the coating wears off of all of them after a few insertions, because I might be the only person that has inspected them closely after multiple insertions.  I want to like these connectors, but it's hard when the coating rubs off so easily. 
I too use the KLE Harmony rca and are sonicly very good  But
their are 2 things myself and other dislike the rca portion is very short ,on some equipment does not hold well, also 
the front portion is 12 min diameter ,then it tapers downto only
9.5mm Which is stupid,for I had ordered excellent double Shielded 6-9s Neotech Copper Wire ,it was 10.5 mm. Meaning I had to cut the plastic body at the taper to fit.wbt,or Furutech not an issue.
irecommend only if under 9mm diameterwire.
I use the KLEI with 16 gauge twisted pair and a 1/4 inch copper braided shield.  Plenty of room.  

Lots of cable builders, including myself, use these and have never had an issue with the quality of the conductor used on the plugs. I make many cables weekly with KLEI bananas and RCAs and am thrilled with the ease of use and sound quality.  
Granny, what audioman is saying is that with the wire he chose, he could not get it to fit because of how the back near the set screws has a smaller ID than the rest of the body. If it did not taper down, the wire he chose would have fit without cutting the body. This is why he thinks it’s stupid that the body tapers down. Of course you can fit a totally different wire through it. That's irrelevant.
The KLE's are the only plugs that taper?
Goodness that opening is big enough to fit a 12 gauge twisted pair. I have done it .... with a shield! Most ICs are made with16gauge and thinner. That is my point. I even made a double run 16ga set using the Schroeder Method. Fits easily. Confused with this one for sure. However, I suppose if one starts adding Thicker synthetic coverings space could be an issue. I have found these types of coverings hurt the sound however.

I never use the screws as they are not enough strain relief IMHO. I always use a nice double wall adhesive lined heat shrink. 
I agree. Opening wide enough to run a water line thru it. I did use the screws on my first set with good results. I may heat shrink over the ends the next time around
Of course these plugs sound good.  You convinced yourself (based on online reviews) that the results were to be jaw-dropping and, or course they were.  Probably better to go to Monoprice or Amazon Basic and get the the wire with the connectors.  Likely that would be way cheaper, would sound as good and you would have matching equipment.
@grannyring  What did you think of the cables you made using the  Schroeder Method?  Any significant difference or improvement?
what is it some china made RCA  $3 JOB ?
what is it some china made RCA $3 JOB ?

Can this be translated into English, please?


I made an RCA set that both I and the customer felt sounded terrific. 
Dyna says " Probably better to go to Monoprice or Amazon Basic"
What wire did you actually use with the KLE's to come up with this?

OP, Have you tried the ETI silver bullet plugs? Just wondering how they compare to the KLE's. 
Sorry to interject but would like to post the following......TEO Audio, at one point, used the ETI plug in several of our cables but have since switched to KLE because we felt that it was a much better sounding plug.

Thanks taras22 / Good to know (it's less expensive also)

No! Lol

Yeah, I really don't get why you would ever consider using that stuff on a connection that was already soldered, just like every other connection in your preamp, amp, crossover, etc.
Treat all those connections.  I have.  Speaker crossover etc.,, Fantastic stuff.  Should try it before you knock it.  I would be willing to split the cost of a vile with one or two of you.  
Can you explain your process for treating a soldered connection? I think dgarretson was describing something different, but I would like to hear your method.
I compared Duelund Cu-Sn 16avg interconnects with KLEI Pure Harmony connectors and Duelund Gold connectors.KLEIs have better separation but Duelund Golds sound more natural in terms of tone. For example, high octaves of piano sound much more real with Duelund Golds.
At least, I can say, this sound suits better to my system with vintage Altec 604E. Most of modern speakers sound more open, bright and emphases high frequencies.
KLEI Pure Harmony tame harshness and make upper mid sound more polite. So, for most modern speakers KLEI may suite better. Also KLEI sound very clean and give you listen all melodic lines in music very well. Duelund RCA are not bad in this parameter too, but KLEI are notably better.

The total contact paste is really not a paste as the consistency helps it spread very easily and a little bit goes a long, long way. The kit comes with a nice painters style mini brush that is used to paint all connectors Etc...

I simply paint the surface of the solder connections and component lead outs on point to point wired crossovers and tube amps. I also paint the tops of capacitors and transformers.

One just needs to be very careful not to produce an unintended conductive bridge. Just use a very little amount on the brush as it spreads very thin, and as I said l, goes a long way. Do not apply so it’s thick and gloppy, but rather thin and spread evenly.

It also works wonders on power cord spades, speaker connectors, RCA male pins, tube pins etc...

While inside my speaker crossover I also pasted/painted the internal speaker wire connections where they solder to the drivers.

Many won’t go as far as I did as they are not comfortable working inside of gear and I understand that. However, a good place to start is certainly on all the various connectors in our system.
  • Here is a recent review.  Easily the best mod or tweak I have ever encountered in my 35 years of audio.  

OP: great thread. My digital IC and I believe most (if not all) of my Teo Audio IC's are terminated with these plugs.
Hi @grannyring ,

Contacts of RCA connectors, tube sockets, power plugs, tonearm headshell bayonets,...
are a big issue in audio.
Does Total Contact Enhancer solve all this issues?

I built a RCA cable pair with KLE RCA Pure Harmony and Duelund DCA20GA.
They work together very well. It is a very good match for my system.
I like this combination more than Pure Harmony + DCA16GA or Duelund Gold RCA + Duelund DCA20GA.
This thread is quite interesting....

There are the people that like/love the KLEI plugs 

And the people that think they are unworthy - mainly because the silver appears to wear off.

Has anyone considered that the problem may not be with the plug, but with the socket into which the plug is being inserted?

If the socket is even slightly larger than spec, it will exert additional force on the plug which will of course wear off the silver.

I say this because I have been using KLEI plugs for around 5 years and the only model of plug that I have experience the silver wearing off is the Copper Harmony - and even that was after several dozen insertions.

I have used these plugs on several different components, so there is a likelihood that at least one of them would wear off the silver coating, but I have to admit that on all my cables the silver is still intact

I now only use the Absolute Harmony because it is superior sound to all other models in every respect.

For the person that wondered how the Harmony plugs compared to the original Bullet plugs - even the copper harmony was superior to the Silver Bullet - and as I worked up the line the improvements kept coming.

Here's my review of the Copper Harmony vs. Silver Bullet

Happy Listening - Steve

Hi @williewonka ,
What is a difference in sound between Absolute and Pure Harmony?
Alex - the Absolute Harmony and the Pure Harmony both perform extremely well.

Perhaps the most telling evaluation was on my turntable which has one piece silver litz harness. The cartridge is a Soundsmith Mod’d Denon 103 with an optimized Countour Line Contact stylus on a ruby cantilever and the phono stage is a Simaudio Moon LP5.3

The following link will give you more details...

I also used the KLEI gZero20 IC’s which had the Absolute Harmony plugs on them for my digital rig and they provide the same outstanding quality.

I now use them on my own "home brew" Helix cables that allow these RCA’s to perform to their highest abilities. 

Hope that helps - Steve

Hi @williewonka ,

Thank you for answer.
Do you think the tonearm cable RCA connector is the most sensitive place in audio system?
I use Furutech 126(G) for my tonearm cable.

I used KLEI Pure Harmony with number of cable in my system.
It always sound very clean, clear and quiet. In some combinations (of cables, speakers and components) it sounds just right, but in some other combinations it can sound too polite in upper mid.
So I need try to use KLEI Pure Harmony instead of Furutech and than I will see how does it matches.

Do you think the tonearm cable RCA connector is the most sensitive place in audio system?
Yes and no...
- the amplitude of the signal is very small and therefore introduces the least amount of noise between the conductors within that cable.
- However, because the signal amplitude is so small it is amplified significantly more than the signals in other IC's within a system and any noise injected into the cable (e.g. from external RFI/EMI) can be quite noticeable

However - to get the very best out of a turntable a one piece harness, like those sold by Cardas, is perhaps the best approach, AND then install the best RCA you can afford - for me that is the Absolute Harmony.

I use Furutech 126(G) for my tonearm cable
I have used that very RCA in the past on my tonearm and other interconnects, but I now prefer the significantly finer details and dynamic performance that the Absolute Harmony plugs provide.

Hope that helps - Steve

Hi Steve,

I already have KLEI Pure Harmony. I can try them instead of Furutech 126 (G) in my tonearm cable.
I know that KLEI Absolute Harmony are even better. But I have to buy them.
If I like KLEI Pure Harmony much more than Furutech in this cable I will think about buying KLEI Absolute Harmony.

Alex, The improvements between the Absolute Harmony and the Pure Harmony are small and you really have to listen intently to hear them.

In my reviews I believed it was important to report on any improvements I heard (or not)  so that people could make a decision based on my observations. 

As a reviewer I have to have a "benchmark" to compare other products too. For me, that benchmark is the Absolute Harmony.

When I review a product it generally takes at least a couple of months of...
-  "acclimating" my ears to my baseline setup, 
- installing the new product, 
- allow sufficient time for burn-in/settlement 
- and then listening many times to around 200 tracks I have selected for their various "virtues".

But - In the "Real World" - where most people simply sit down to listen for a few hours - then I tend to temper my recommendations. 

So -  in real world terms - if you are thinking in terms of a quick A/B comparison,  I would  have to say you might not be able to discern the difference between these two RCA's. 

But if you are the type of person that has to have to have the best then the Absolute Harmony is your goal.

Since you have already purchased the Pure Harmony I think it would be more prudent to use them and simply enjoy the results and DO NOT let those "nagging thoughts" of having to own the absolute best (exscuse the pun) get the better of you.

If at some point in the future you happen to find yourself needing more RCA's, you could then try the Absolute Harmony, but I believe there is no need to replace the Pure Harmony you currently have. Just enjoy them :-)

Enjoy the music - Steve

Hi Steve,

I just soldered KLEI to the tonearm interconnect instead of Furutech 126 (G).
I use WBT solder. 
The first impression is: the sound more transparent, better separation, details low level details, better focus. The tone is OK.
What I didn't like - on some records, the sound is too calm, too polite.
I know I need more time for solder break-in and I need to listen more different kind of music and records.
The good thing - it is impossible to make quick A/B, because to exchange RCA - cable should be re-soldered :-)
So, in any case it will be a long term listening test.

Alex - also remember the RCA's need considerable burn-in time.

From new, I found small improvements still occurring after 300 hours.

If previously burned in - I would give them at lease 60 hours to sound their best.

Happy Listening 
I have found very, very little difference going from the Copper to Silver to Pure. I feel there are two real choices. Copper Harmony if cost is an issue and Absolute Harmony if you want the best. The other two add unneeded complexity to the line. My honest opinion.

These take 100-125 hours to burn in fully based on my evaluations.
Alex - RE:

What I didn’t like - on some records, the sound is too calm, too polite.
Maybe it’s the actual wire that sounds "too polite" ?

The RCA’s have always responded very well to the various wires I have tried

I have been messing with cables for over 5 years and it never ceases to amaze me how the wire, or RCA or the insulation and even the cable geometry can mess with the sound.

Also - humans tend to attribute a change in sound to the latest change made - in this case the RCA’s - when in fact the RCA’s could be highlighting a property of the wire or cable itself.

The degree of difference you can hear by installing these RCA’s is determined not only by the RCA, but also the wire + the geometry of the cable

So unless you have very good wire and an excellent cable geometry then you may not hear the true benefits of these RCA plugs, or even the differences between them

The Helix geometry is perhaps one of the most transparent out there.
- I use Mundorf Silver/gold solid wire for the signal wire on all IC’s, but Duelund wire is also very good.

See: http://image99.net/blog/files/category-002ahelix-interconnect-cable.html

If the DIY Helix cable is not to your liking, then I would recommend the KLE Innovations Interconnects. I have tried most of their earlier designs and they were all excellent performers. The gZero10 is very good. They seem to have dropped the gZero3/6/20 IC’s

I have not tried the QFLOW or zPURITY series, but I read good things about them

Happy Listening

@grannyring - re:

I have found very, very little difference going from the Copper to Silver to Pure. I feel there are two real choices. Copper Harmony if cost is an issue and Absolute Harmony if you want the best. The other two add unneeded complexity to the line. My honest opinion.
I tend to agree somewhat with this comment - with the exception that the Silver harmony is my starting point, simply because in my system the improvement over the Copper Harmony was most noticeable. Also, the silver does wear off of the Copper Harmony pins, but the Silver Harmony seems to wear much better.

And for the few extra bucks the Absolute Harmony cost (that is compared to the Pure Harmony), it makes sense to buy them in place of the Pure harmony, because otherwise you'll always be wondering just how much better they might be.

Regards - Steve