Harman-Kardon GB4 Optional External Power Supply, Meters not showing any signal, No Mix output

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 (DPS-3) can be connected to provide a backup power supply. There is a dedicated connector on the rear connector panel.

16 GB4 User Guide