The main purpose of a splitter
transformer is to isolate the shield
grounds between two portions of a
sound system. By using the setup
illustrated, the stage mic (or keyboard
mixer, guitar, etc.) is connected directly
to the monitor console input. At the
same time, the signal from the mic
goes through a transformer. The
transformer illustrated has two completely
separate Faraday shields
(electrostatic shields), one for the
primary and one for the secondary. The
primary shield is tied back to the
monitor console, while the secondary
shield is tied to the cable shield that
goes to the main house console. In this
way ground loop hum protection, and
phantom power continuity are maintained
for the stage mic (or instrument),
while full shielding is also
established between the split point and
the main house console.
The particular transformer shown
here is a Jensen model JE-MB-C,
selected due to its very low distortion,
low phase shift, wide bandwidth, and
isolated shields. Information on this