Power standards for electrical distribution were adopted many decades ago and haven’t changed significantly since. With the advent of sensitive electronic applications, electrically induced interference has become a matter of concern to engineers. When electrical interference is present in any sensitive electronics, equipment performance will be limited by the noise. The problem is critical in many areas of high-tech electronic engineering, among them, the sound recording and video industries. A very low noise level is crucial in these areas because literaly, the noise can be seen and heard.
The dynamic range of the entire electronic signal chain determines the quality of the final product in all recording environments. The presence of any electrical interference at all lowers the S/N ratio of the recording. This limits the subtle detail and realism of the sound or image. Low level signals are lost in the noise floor of the system.
Sound quality can also be affected by intermodulation distortion occurring as a result of the presence of ac noise in the audio or digital signal bandwidth. Even if the noise level is inaudible, it is likely that program material will be colored by the presence of electrical interference.
In more sophisticated areas of application, for example high-end digital signal processing (such as broadcast automation or even MDM recording), unacceptable error rates are often attributed to background electrical interference. Digital jitter is the “smoking gun” that points to high frequency AC noise. Digital jitter is caused in part by high frequency electrical interference approximating the bit stream rate of the digital signal.
Balanced power eliminates all of these problems because there is never ac interference present on the ground to invade signal circuits. Balanced power often increases the dynamic range of a recording system by 16db or more. When balanced power is applied, ground loops and hum problems, even subtle ac noise coloration becomes a thing of the past. The difference can be astonishing.