Unbalanced Instrument Cable
Most musical instrument sound pick-ups such as those in electric guitars are comprised of high impedance circuits driven by voltage, in other words by very small electrical current flow. Therefore, so-called MICROPHONICS (noise) becomes a critical problem. (Microphonics means noise that is generated when the cable is moved and or tapped when the cabling circuit is a high impedance link.) Guitar cables must be counter-measured against this, so, a conductive PVC layer is placed under the shield conductor in most cases even though it may have a bad affect on audio sound quality.
Therefore, the conductive PVC (black carbon PVC) layer must be removed together with the shielding conductor when wiring, otherwise we receive a strange claim that the cable is shorting.