[. . . ] Furthermore, the Dwell, Mix and Tone knobs control the all-tube reverb allowing a "custom" designed reverb tone. Still, the footswitch offers the ability to remotely switch on and off both the Vibrato and Fat features. With the built-in effects loop, adding an external signal processor is a snap. [. . . ] INTENSITY - Adjusts the level of signal modulation of the Vibro-King's Vibrato feature. Turning this knob completely counter-clockwise turns the Vibrato feature off. Should this bulb burn out, turn off and unplug the amplifier, unscrew the pilot jewel and replace the lamp with a type T47 bulb. REAR PANEL FUNCTIONS A. LINE CORD - The Vibro-King is equipped with a grounding type supply cord to reduce the possibility of shock hazard. FUSE - The fuse is in the AC supply of the amplifier and will help to protect the amplifier in the event of an electrical fault or tube failure. If a fuse blows, replace it only with one of the same type and rating. (Refer to the specification page to determine the correct fuse type and rating for your amplifier). NEVER use a fuse with a higher current rating as this could damage the equipment and present a serious safety hazard. If the amplifier repeatedly blows fuses, it should be taken to an authorized Fender service center. When the amplifier is in the OFF position, the amplifier is completely shut down. STANDBY SWITCH - When the power switch and this switch are ON, your Vibro-King is ready to perform. In the STANDBY position, power is supplied ONLY to the tube filaments and sound will NOT come out of the amp. Using the STANDBY SWITCH during short breaks eliminates tube warmup time and will increase tube life. MAIN SPEAKER JACK - This is the main plug-in connection to the speakers and must always be used as their primary connection. F. [. . . ] (Eliminate any effects pedals and try another guitar cord. ) Check under all tube covers to see if the tube filaments are glowing. If, after checking all of the above, your amplifier is not performing correctly, consult your nearest authorized Fender service center. COVERING CARE Your Vibro-King is covered in genuine Tolex for long life and lasting good looks. To clean the Tolex covering, use a sponge and a light soapy water solution. [. . . ]