and a smooth, musical sounding response. A separate 5 band equalizer is provided for each the TUBE and the FET
channels. This fully active EQ has a wide range, so generally, a little EQ goes a long way.
Low Frequency - 80 Hz and below
Low-Mid Frequency - 250 Hz
Mid Frequency – 650 Hz
Global Signal Shaping Switches and Controls
— There are 3 separate shaping filters on the GBE 1200. The “L.F.
EXTEND” (low frequency extend) lowers the low frequency roll-off response of the preamp (between 30 and 45 Hz)
to allow the full effect of 5+ string and extended scale instruments. The amount of extension is adjustable depending
on the setting of the corresponding control. Use this function with care due to the power of this amplifier. The “MID
SCOOP” function introduces a midrange scoop at approximately 450 Hz, with a lower “Q” than typical equalization
provides. The amount of scoop is adjustable with the corresponding control. The “H.F. ATTACK” (high frequency
attack) function increases brightness and sparkle (approximately 4 KHz) of the signal, allowing exaggeration of
percussive effects and string sound. The amount of attack is adjustable with the corresponding control. All 3 filters are
footswitchable with the 5 button footswitch. A bright blue LED located above each switch indicates when the filter has
been selected. All switches must be in the out position in order for the 5 button footswitch to work properly.
Master Volume
— The “master volume” adjusts the signal level sent to the power amplifier. Best results are usually
obtained when this control is set between the 9 o’clock and 3 o’clock positions.
Output Limiter
— The “output limit ” switch engages the internal power amplifier’s soft clip limiter. This limiter allows
simulation of tube output stage saturation as the amplifier nears its maximum power. The limiting action is particularly
musical sounding, even when driven hard. A bright blue LED located above the switch indicates when this feature has
been selected.
Master Section Status Indicators
—
• The “POWER JEWEL LIGHT” indicates that the amplifier is on and the low voltage power supplies are active.
• The red “PROTECT LED” indicates that the amplifier is in “protect” mode and the output relay is de-energized. This
LED will illuminate for approximately 3 seconds during power switch-on and switch-off. It is normal for this LED to glow
while continuing to monitor the internal conditions for a few seconds after the protection relay has closed. It will also
illuminate during any internal fault condition. If this happens, turn the amp off and consult a repair technician.
• The red “THERMAL LED” indicates that the amplifier has overheated, engaged the protection circuit, and shut down.
This circuit is self-resetting when the offending condition (blocked air vents, foreign body stuck in fan, etc) is corrected.
• The amber “2 OHM LED” indicates that the power amplifier’s 2 ohm POWERFLEX mode has been selected. This
LED monitors the operation of the high voltage power supplies.
• The blue “SIGNAL LED” indicates that the power amplifier is receiving signal (over several watts output) and all is
well!
• The red “CLIP-LIMIT LED” indicates that the power amplifier is near its maximum power and/or the limiter threshold
has been crossed. Driving approximately 6dB beyond this point with the “OUTPUT LIMITER” engaged will cause the
amplifier to gradually begin to clip.
4
High-Mid Frequency – 1650 Hz
High Frequency - 4000 Hz and above
