The next Generation of Bullet Plug

The KLEI™Harmony Phono/RCA Plug is a new revolutionary approach to KL’s (Keith Louis Eichmann) previous Bullet Plug design, which itself was a revolutionary approach to Phono/RCA connection. It represents a wholesale rethinking of something as basic as the venerable Phono/RCA plug; a connector designed over Sixty years ago by The Radio Corporation of America (RCA).

KL’s objectives for improving the humble RCA plug are… improved conductivity, enhanced signal integrity, higher resolution, and improved connection. These objectives are important and significant in critical areas of Electron Charge Flow and Signal Integrity for High Resolution audio performance and requires close attention to all areas of Connector design, as follows…

  • Geometry/Materials/Mass – KL’s (proprietary) Signal/Ground formula/architecture, ensures Optimum mass of Metals and Dielectrics are used to avoid skin effect, maintain structural Strength and Reliability, and minimise Reactive, EF, & EMF effects. Controlling these effects ensures that a complete, full, and extended Signal frequency range, and the harmonics, are transmitted from Component to Component, which further ensures that the listener enjoys a complete, full, extended, detailed, involving, and musical presentation.
  • Metallurgy – we/KLEI do not waste the effort gained in the other aspects of our designs by compromising with metals less conductive than Copper or Silver.
  • Metal Conductivity %IACS (IACS – International Annealed Copper Standard)
    • Silver – >105%
    • Copper – >100%
    • Silver (Machinable) – 92.5% ~ 96%
    • Tellurium Copper (Machinable) – 90% ~ 95%
    • Gold – 65 ~ 75%
    • Aluminum – 60 ~ 65%
    • Bronze – 15 ~ 48%
    • Beryllium (low/high copper content) – 17% ~ 43%
    • Rhodium – 35% ~ 38%
    • Brass (low/high copper content) – 25% ~ 37%
    • Tungsten – 31%
    • Nickel – 24%
    • Palladium – 16%
    • Platinum – 16%
    • Tin – 15%

KLEI™Harmony Phono/RCA Plug Architecture (since Sept 2014, began Feb 2014)

The conductive pins of the KLEI™Harmony Phono/RCA plugs are formed/manufactured using our proprietary high conductivity alloys, we believe having an IACS rating >101%, and even >106%, to ensure the highest levels of conductivity. When compared to a typical gold plated brass connector used in the vast majority of deluxe Phono/RCA plugs, the KLEI™Harmony Phono/RCA plug range, utilizing our proprietary high conductivity alloys, achieves improvements in conductivity exceeding 320%. Proven metallurgical choices result in improved signal transfer and electron flow, which is consistent with high resolution interconnect/digital cables.

Our proprietary high conductivity alloys vs ‘Pure annealed Copper/Silver’…

  • Our Extrapolation, Testing, and Reports, that we have received are confirming and allowing/permitting further evaluation and extrapolation, as follows…
  • Electrically, the proprietary high conductivity alloys utilised in the KLEI™Harmony Phono/RCA plugs are equivalent, and even superior, to ‘Pure annealed Copper/Silver’.
  • Pure annealed Copper/Silver (>=99.9999% purity)… >=100% and >=105% IACS conductivity, respectively.
  • KLEI™Harmony Phono/RCA plugs proprietary high conductivity alloys… we believe >101%, and even >106%, IACS conductivity.
  • Our evaluation is that our KLEI™Harmony Phono/RCA plugs proprietary high conductivity alloys are equivalent, and even superior, to ‘Pure annealed Copper/Silver’…
  • As such, we believe that our proprietary high conductivity alloys can be called PURE and equivalent to 99.9999% pure annealed Copper/Silver.
  • Further, we shall now refer to our proprietary high conductivity alloys, that we believe are IACS >101%, as KLEI™PureCopper or KLEI PureCopper™ or KLEIpureCopper™ or KLEIPureCopper™, and our proprietary high conductivity alloys, that we believe are IACS >106%, as KLEI™PureSilver or KLEI PureSilver™ or KLEIpureSilver™ or KLEIPureSilver™.
  • Mechanically, the KLEI™Harmony Phono/RCA plugs proprietary high conductivity alloys are much stronger than ‘Pure annealed Copper/Silver’ and nearly as strong as the Brass alternatives.
  • Sonically, we believe that the KLEI™Harmony Phono/RCA plugs proprietary high conductivity alloys are therefore superior to ‘Pure annealed Copper/Silver’, especially when designed in accordance with KL’s (proprietary) Signal/Ground formulae.
  • KL’s (proprietary) Signal/Ground formulae produces a purposeful metallurgical relationship between the Signal and Ground/Return conductors which we believe produces a superior Sonic performance, but ‘the proof is in the listening’.
  • Feedback and Impressions are welcome.

Conventional RCA’s are designed with a Metal Collar, which is prone to electron turbulence called Eddy Currents. In addition to this Capacitive Reactance and Micro-Arcing are additional artifacts of the metal collar architecture.

  • To combat this KL opted for a Single Point Ground contact similar to Star Ground/Earth in high-end electronics which in turn eliminates every vestige of Eddy Current Turbulence, Capacitive Reactance, and Micro-Arcing.
  • Further, with the KLEI™Harmony Phono/RCA Plugs design, KL has redesigned the Single Point Ground pin with an optimised shape, mass, and thickness.

Our proprietary high purity silver plating (>106% IACS) is applied directly to the conducting surfaces of the KLEI™Harmony Phono/RCA Plugs pins, as required. This produces the performance/sound characteristics of 4-nines pure silver (>106% IACS) and no additional plating is required to preserve signal quality.


KL believes he has, with this new KLEI™Harmony Phono/RCA Plug blueprint, solved a series of problems that collectively degrade audio/video performance and that do so in an additive manner. The importance of this innovation and redesign cannot be overstated. Its ramifications extend to every Phono/RCA interface in which high quality signal transfer is an issue. Extensive listening and critical comparisons played a major role in the evolution of the design, confirming at every juncture the audibility of properly applied science in even the area of Phono/RCA connection.

In Summary, the KLEI™Harmony Phono/RCA plug family, which can be viewed as The next Generation of Bullet Plug, is the Sonic culmination of KL’s (proprietary) Signal/Ground formulae when applied to the metallurgical relationship between the Signal and Ground/Return conductors. The Sonic results are the KLEI™Harmony Phono/RCA plug family, beginning with the KLEI™Classic Harmony Phono/RCA plug through to the KLEI™Absolute Harmony Phono/RCA plug, which is the highest Sonic performer of the family.