Are instrument cables used for high-impedance or low-impedance lines?
Generally, the source impedance is the determining factor in cable selection. Instrument cables are used for a wide range of sources. Many keyboard instruments, mixers, and signal processors have very low (50 to 600 ohm) source impedances. On the other hand, typical electric guitar or bass pickups are very inductive, very high impedance (20,000 ohms and above) sources. Typical load impedances are greater than 10,000 ohms, which limits the electrical current flow to a very small amount on the order of a few thousandths of an ampere (milliamps). How much power does an instrument cable have to carry? The voltages encountered range from a few millivolts, in the case of the electric guitar, to levels over ten volts delivered by line-level sources such as mixers. By Ohm’s Law this represents power levels of less than a thousandth of a watt. What kind of frequency response does an instrument cable need? What are the lowest and highest frequencies produced by the source? The bandwidth spans th
