Darren Chan

Darren Chan


The Chronicle

Sound quality was my central obsession in the audio production days. It was in 2019 when I chanced upon cable rolling during the days of mixing and mastering for small local producers in Singapore. Coming from a high-end cable skeptic, I made my first DIY USB Cable. thinking that there should be almost little to no sonic difference— but only to find a noticeable difference in sound quality. 


Many stock USB cables at that time were not satisfactory in getting a consistent 90 ohm impedance. My first USB cable was the KYAN USB, sleeved in the same red tubular braid as the RUBI Series. Months of research went into the different types of dielectrics, twisted-pair geometry, shielding, and conductors. In the end, I managed to obtain 90 ±6 ohms of tolerance despite the cable being hand-made. The RUBI USB then came about as a more technologically advanced refinement of the KYAN USB. This resulted in greater textural/timbre detail, neutrality, and coherence without listening fatigue. 


The ethos of an engineering-centric design, coupled with such a sound signature laid the ground for the entire RUBI Series lineup.




Grounding of a cable is an important aspect of audio cables that helps to minimize signal noise, interference, distortions, and transient response.

The proper grounding of a cable can significantly impact the sound quality even at radio frequencies that are much higher than our hearing capability. Most grounding schemes in cable incorporate the shield as a single ground path to drain out EMI. An issue with this is the formation of signal reflections and standing waves at MHz frequencies, which create resonances within the cable that worsen and distort EMI.

VGround strategically eliminates resonances in ground wires by propagating EM waves across different signal pathways. This cancels out resonant behavior at specific ranges of frequencies depending on how we design the stranding geometry. The result is a flat impedance and low resonance cable across the spectrum.


Since the inception of the RUBI series, we have found that a star-quad design is fundamentally one of the most well-known and best geometries for analog interconnects.

The four wires in a star-quad cable are arranged in a star and twisted in a specific way to:

  • Reduce Common Mode noise which manifests on both conductors at the same time
  • Improve magnetic immunity against magnetic interferences from system components
  • Reduce magnetic field emissions that interfere with sensitive lines
  • Lower inductance due to the smaller magnetic field, resulting in improved transients and dynamics

the QUADEX design in RUBI line interconnects is based of the star-quad geometry. Star-quad cables are known for their high level of noise rejection due to two concepts: Magnetic immunity and High common-mode rejection.

Magnetic Immunity

The twists in the QUADEX star-quad structure are position so that electromagnetic fields from external sources are more effectively cancelled out. This is because the four conductors are arranged with each conductor positioned at a different point of the star. This geometry helps to distribute the magnetic fields from external sources evenly across the conductors, which results in more effective cancellation of the induced voltages and better common-mode noise rejection. This can help to improve the overall signal-to-noise ratio and reduce the level of noise in the audio signal by an additional 20-30dB resulting in a low noise floor and perhaps, a perceived ‘darker background’.

Field Cancellation

The fact that each conductor in the star-quad cable is positioned at a different point means that the current flowing through each conductor is not flowing in the same direction. Thus the magnetic fields generated by each conductor are oriented in different directions, which further helps to reduce the inductance of the circuit. This phenomenon is known as field cancellation.


The benefits of effective field cancellation are: better noise rejection, smaller magnetic field emissions, reduced proximity effect and loop inductance. Since magnetic fields generated by a star-quad cable are generally considered to be smaller than those generated by a twisted pair cable, using such cables to transmit low frequencies can be beneficial, especially near components that are sensitive to magnetic interference.


What makes QUADEX special is, in addition to the star-quad geometry, a special medium between each wire is used to control magnetic field interactions between each conductor, further reducing proximity effect. Therefore, the low inductance and proximity effect in QUADEX Star-quad design methods produces better transient response, resulting in a more natural and expressive sound.


In the bronze age of Greek archery, KAIROS refers to the right moment when an archer finds the perfect opening to shoot his arrow and strike the target at the right time and place.

This is a metaphor for the alignment of TIME in analog and digital audio signal cables. An important parameter in cable design that relates to the arrival time of an electrical signal is the Velocity of Propagation (VP). VP changes depending on the inductance and capacitance of the cable—but it also slows down drastically as you go down from 20kHz to 20Hz. This is true for analog interconnects with driving a high impedance load. This means more phase shift as the frequency lowers. This, combined with the variation of phase in stereo pairs of cables means smeared imaging. 

A way to combat this is to design cables with dielectrics that offer linear capacitance across frequency, and tightly regulate the dielectric thickness with advanced manufacturing techniques, which is why we chose PTFE (or Teflon) as the dielectric for its stable performance in RUBI cables. As a result, the phase shift is reduced down the audio frequencies, improving imaging and refinement of the sound sources in the imaging.

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