How do we identify audio patch panels for the digital world?
Analog audio patch panels and AES/EBU digital audio patch panels should not be thought of as interchangeable. The AES/EBU signal is a 3 MHz SQUARE WAVE at about 3 volts peak. Therefore, it crosstalks a lot more than does analog audio. When one square wave crosstalks at a lower level into another, it has the apparent effect of “blurring” the leading and trailing edges (the rising and falling “walls”) of the square wave. This is called, among other things, “jitter”. The patch panel you buy for AES/EBU should be one of those designed for “low jitter”. So, the two should be in separate patch panels. Possibly with dissimilar plug sizes to prevent accidental interconnection. At NPR Headquarters, when we installed the System Technical Center (STC), which has a modest amount of AES/EBU signals, we chose ADC DAB3-14MKIINS patch panels for the AES signals. These use Bantam size jacks with 48 jacks wide by 2 jacks high in two rack units. this was in late 1993. Ours are serial numbers 18, 19 and 2
