This balanced headphones cables is a parallel project with balanced headphones amplifier. Sennheiser HD6XX is a good performance headphones. It really love high power to drive it on it's true potential. This is because the impedance of this Sennheiser HD6XX is 300 ohm. Mostly for this high impedance headphones are use by the professional audio. For sure the power output from most digital audio player cannot drive well this headphones, thus not brings the true potential of this headphones either. That is why this balanced headphones cable for Sennheiser HD6XX project is come in before the amplifier. Approaching by using a balanced cable to Sennheiser HD6XX headphones is to double up the power since both polarity of signal wave are amplified. Another advantage from balanced headphones cable is by nature the noise should be reduced and better compares to the single ended cables.