Radial Engineering Relay XO Balanced AB Signal SwitcherThe Radial Relay Xo is a 1 in, 2 out balanced audio switcher designed to route the output of a microphone to two different audio inputs. This, for instance, enables a vocalist to switch his mic between the main PA system and the monitors so that he can discreetly communicate with other band members or the technical staff. This is of particular importance for artists that employ in ear monitors. You can also use the Relay Xo to send the output of a