The TRS input jack is wired in parallel to the TRS jack 'OUT-b' and the female xlr connector 'IN-a' on the connector panel of the frame. This feature allows direct connection of the instrument to an amplifier without additional y cables.
If the input is driven from the output of a power amplifier, the input pad should be used to avoid distortion due to the high output levels. With pad, the input impedance is > 20 kOhms.
unbalanced or balanced Mode
The input defaults to unbalanced mode and can the altered to balanced mode by the BAL swtich. With balanced mode, the + phase (hot) is connected to the tip and the - phase (cold) is connected to the ring of the input TRS connector. With unbalanced mode, ring and sleeve is connected.
Independent of the operation mode (unbalanced or balanced) the input is normally connected to the internal ground. The Ground Lift switch disconnects the internal ground from the ground of the input jack on the front panel. With unbalanced mode, there ring and sleeve are still connected.
bThe GROUND LIFT SWITCH does not disconnect the ground of the TRS connectors on the connector panel of the frame that are wired in parallel to the input jack on the face plate. If amplifiers are installed on one of these connectors, humming can be caused by this ground connection. If this is the case, please use the xlr connector 'IN-a' instead. The pin 1 of this connector is also disconnected from the internal ground by the ground-lift switch.