Ampeg B4R manual Front Panel Controls and Their Use Con’t

B4R Bass Amplifier

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

19 20 21 22

2kHz 5kHz 8kHz

LEVEL

POWER

ACTIVE

TREBLE EFFECTS MIX MASTER

GRAPHIC EQ

FREQUENCY BALANCE

300HzFLAT

DRY

WET

LIMIT DEFEAT

LIMIT

50Hz 1kHz LO

HI

10 11 12 13 14 15 16 17

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.

5