[. . . ] The GUITAR channel has a "FAT" switch to boost the gain, especially at low frequencies. It is equipped with all-tube generated reverb and vibrato which, unlike many old amps, works in both channels. The speaker in the "Custom" Vibrasonic is an Eminence ultrahigh power driver with exceptional sound and fidelity for electric or pedal steel guitar. [. . . ] STEEL CHANNEL VOLUME CONTROL - Adjusts the overall loudness of the STEEL channel. TREBLE CONTROL - Adjusts the amount of high frequency boost (accentuation) or cut (attenuation) in the STEEL channel. MIDDLE CONTROL - Adjusts the amount of mid-range frequency boost or cut in the STEEL channel. FAT SWITCH - This switch provides an extra boost to the low frequency response of the GUITAR channel. K. GUITAR CHANNEL VOLUME CONTROL - Adjusts the overall loudness of GUITAR channel. TREBLE CONTROL - Adjusts the amount of high frequency boost or cut in the GUITAR channel. D. M. MIDDLE CONTROL - Adjusts the amount of mid-range frequency boost or cut in the GUITAR channel. BASS CONTROL - Adjusts the amount of low frequency boost or cut in the GUITAR channel. Note: If all tone controls are full counter-clockwise, there will be no sound. REVERB CONTROL - Adjusts the amount of reverberated signal that is mixed in with the original dry signal. Turning the control full counter-clockwise turns the REVERB feature off. The REVERB feature can also be turned on and off using the footswitch. E. F. G. BASS CONTROL - Adjusts the amount of low frequency boost or cut in the STEEL channel. Note: If all tone controls are full counter-clockwise, there will be no sound. [. . . ] A very light soapy solution on a sponge may be used to remove dirt and residue that may accumulate in the grain. Be careful not to let any liquid come in contact with operating surfaces. DO NOT have the amplifier plugged into a power outlet when cleaning. TROUBLESHOOTER`S CHECKLIST · · · · · · · · · If the amp is set up but does not function, check the following items: Is the amp power cord properly plugged into an electrical outlet? [. . . ]