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The front panel controls and their use – con’t – Ampeg B4R User Manual

Page 5

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5

The Front Panel Controls and Their Use – Con’t.

12. GRAPHIC EQ: This switch activates the graphic equaliz-
er. When a footswitch is used, this switch is disabled.

13. LIMIT DEFEAT: The B4R employs internal limiter circuits
to help keep the power amplifier’s output clean at extreme
volume levels. (All amplifiers may begin to clip their output
signals as they approach maximum output levels, resulting in
potentially speaker-damaging distortion.) These circuits may
be disabled by depressing this switch. This may result in an
increase in output power, but also increases the possibility of
distortion. Use discretion whenever playing with the Limit cir-
cuits off.

14. MASTER: This control sets the overall output level of the
amplifier. For the lowest possible noise level, adjust the Gain
control as described in #5 and use this control to obtain the
desired volume level.

15. LIMIT LED: This LED will flash any time the internal limit
circuit is called upon to keep the amplifier’s output signal
clean. This indicates that the amplifier is nearing full output
and the limiter is keeping it from clipping the output signal.

16. FREQUENCY: This control sets the crossover point
between the Biamp High and Biamp Low Outputs when
using the amplifier in the biamp mode.

17. BALANCE: This control adjusts the relative level
between the low and high frequency biamp signals when
using the amplifier in the biamp mode.

18. 9-BAND GRAPHIC EQ: These sliders control the ampli-
tude of the frequencies indicated above each control. The
center position of each control is flat: sliding the control
upward will increase the output level of that frequency; slid-
ing the control downward will decrease it.

The Graphic EQ can be used in two ways: 1) To fine tune your
sound, make small adjustments at the desired frequencies and
leave the EQ on throughout the entire session. (This is great for
adapting to varying room acoustics when going from club to club,
etc.) 2) For a completely different sound, make larger adjustments
and only activate the EQ when you want a “second channel” sound
(such as during bass solos).

19. LEVEL: This is the output volume control for the Graphic
EQ and only affects the signal when the EQ is engaged. If
the EQ’d signal is too soft, slide the Level control up; if it’s too
loud, slide the control down.

20. POWER LED: This LED glows green when the Power
switch (#22) is ON.

21. ACTIVE LED: This LED illuminates when the EQ is on.

22. POWER: This heavy-duty rocker switch applies the
power to the amplifier: the amp is ON when the top of the
switch is depressed, OFF when the bottom of the switch is
depressed.

B4R Bass Amplifier