There’s No Sound on the Speaker Output, What Can I Do? – Help Center

If there is no signal from the Speaker Output, the internal power amp protection circuit may have been triggered. Follow the steps below to resolve it.

Step 1 — Power Cycle the Unit

Turn off the unit.
Unplug the power cable from both the wall outlet and the rear of the unit.
Wait at least 2 minutes to allow the protection circuit to reset.
Reconnect the power cable and turn the unit back on.

Step 2 — Check Cabinet Connection & Impedance

Ensure the speaker cable is securely connected to the Speaker Output jack.
Confirm your cabinet’s impedance matches BIAS Head/Rack’s output: 4Ω, 8Ω, or 16Ω.
Do not connect the Speaker Out to powered speakers or grounded equipment.

Step 3 — Check the Cab Sim Switch

Verify the Cab Sim Switch is in the correct position for your setup. If using an external cabinet, the switch should be set to disengage cab simulation (LED off).

Step 4 — Factory Reset & Firmware Update

Back up your presets before resetting. Refer to How to Backup Amp Presets.

Perform a Factory Reset.
Update the firmware to the latest version and retest.

Still No Sound?

Open a support ticket. The power amp protection circuit may require a hardware inspection.