Meters not showing any signal
Has the input gain been set correctly? (see above.)
Is the source connected to the appropriate input socket for the level of signal?
Do you have something connecetd on the Inserts, and is that external device switched on?
Are the Master faders set at max., are input faders set high enough and is the channel routed to the output being monitored? Is the MUTE switch released on the relevant channels?
Is the appropriate monitor select switch pressed?
Is there a PFL/AFL pressed on another channel?
No Mix output
Check that the Mix Master Fader is up?
No Monitor output
Is a headphone jack plugged in?
Are the Monitor + Phones controls set high enough?
Is the appropriate monitor select switch pressed?
Headphones Distorting
Are the headphones less than 200Ω impedance?
Is the Phones level set too high?
Optional External Power Supply
Although the GB4 has its own internal power supply, an external backup power supply
16 | GB4 User Guide |