The ISO-2 is a passive audio isolator designed to be inserted into the signal chain to block hum and buzz caused by ground loops. The ISO-2 accepts unbalanced or balanced signals and is equally suitable for consumer electronics and professional line-level devices. The ISO-2 can be operated as a dual input and outputs, and since the circuit is passive, no power is required. Whether an unbalanced or balanced signal is connected, the ISO-2 will automatically convert the signal depending on the type of cable and connector plugged in.
The ISO-2 has two combination XLR/TRS input connectors, wired to the AES standard pin-1 ground, pin-2 hot (+), pin-3 cold (-). Balanced or unbalanced output signal can be connected to the input of ISO- 2; the isolated outputs will always be balanced signals. The balanced output of the ISO-2 is line level, meaning that it should be connected to the line input of a mixing console.
Suggestions about distance cable running: Unbalanced cables are much more susceptible to noise than their balanced counterparts, keeping unbalanced cables under 8 meters (25’) in length is good practice while balanced cables can easily extend to 100 meters (300’).
ELIMINATING HUM AND BUZZ AND THE GROUND LOOP
The ISO-2 is equipped with output isolation transformers to eliminate hum and buzz caused by stray DC voltage and ground loops. Computers, CD players and other consumer equipment can be noisy – this is particularly true when incorporating audio with a projector – so isolation transformers can be very useful when combating system noise. The independent Ground Lift switches on the outputs takes this one step further by lifting pin-1 on the XLRs. Computers are often the source for noise problems in audio systems, so greater care is certainly needed to keep things quiet.