Figure 4: MAX DF Setting
Please consult your authorized dealer on the most optimum DF setting for your system.
Fault indication
During the Power On cycle or while the amplifier is operating, if the Power LED goes off and the Mute LED
blinks fast red, then this is an indication of a fault, either a tube fault or power fault. Please check the Deck
LEDs next to each tube to see if you can locate a LED that is lit green. Follow the instructions in the following
sections to determine which type of fault has occurred.
Do not turn off the rocker switch in the back of
amplifier until you have determined which type of fault has occurred and the faulty tube is replaced.
Tube Fault
1. Tube red Fault - Mute LED blinking Red, deck LED green
When any output tube draws excessive current and cannot be controlled by the autobias system the amplifier will shut
down with a fault indication shown by the Mute LED blinking fast red and the Power and Mode LEDs off. The top
deck LED next to the faulty tube will be blinking green rapidly, with all other deck LEDs off.
MB-450 Series III Signature Monoblock Owner’s Manual
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