Ampeg B2 User Manual

4
The Front Panel Controls and Their Use
B2/B2R Bass Amplifier
0
+12dB
-12dB
40Hz 8kHz5kHz2kHz900Hz600Hz300Hz150Hz80Hz
EQLIMIT
PEAK-15dB
ON
GAINPAD BASS ULTRA MID TREBLE MASTER LIMITERINPUT
ON
POWER
0
1 2 87654 109 113 12 13
1. 0dB (INPUT): The signal output from an
instrument (active or passive) or a line level
signal may be connected here by means of
a shielded instrument cable.
2. 15dB PAD: This switch, when
depressed, attenuates the input signal by
15dB. Attenuation allows the Gain control
(#4) to be used over a larger portion of its
range. If clipping is indicated with the Gain
control near minimum, attenuation is need-
ed.
3. PEAK LED: This LED flashes when the
signal level into the preamp approaches
clipping. Adjust the Gain control (#4) until a
strong signal from your instrument causes
this LED to flicker.
NOTE: If the LED flashes frequently with
the gain at a low setting, use the 15dB Pad
(#2) to attenuate the input signal and read-
just the Gain.
4. GAIN: This serves as the input level
control for the amplifier. For the best signal-
to-noise ratio set this control so the Peak
LED (#3) flashes when you strike a string
fairly hard.
5. BASS: This is the primary low frequency
control which allows for 8dB of cut or boost
at 50Hz.
6. ULTRA-MID: This is the primary
midrange control. Rotate the control to the
left of center for a “contoured” sound (more
distant, less midrange output) or to the
right of center for a pronounced (more up-
front) tone.
7. TREBLE: This is the primary high fre-
quency control which allows for 12dB of
boost or 19dB of cut at 5kHz.
8. MASTER: Set the overall output level of
the amplifier with this control. The Effects
Loop and Balanced Out (#19-21,24) are
not affected by the Master control.
9. LIMITER: The B2/B2R uses an internal
Optocoupler Limiter to assist in keeping the
power amplifier’s output “clean” at extreme
volume levels. (All amplifiers begin to clip
their output signals as they approach maxi-
mum output levels, resulting in distortion
which may damage your speakers.) To
engage the Limiter, depress the Limit
switch. Whenever the amplifier is at full
power, the adjacent LED will flash. This is
an indication that the limiter is keeping peak
signals from clipping the output.
NOTE: Playing at full power with the Limiter
off will give you increased output power, but
the sound may be distorted. Use discretion
when playing without the Limiter.
10. EQ ON SWITCH: Depress this switch
to activate the Graphic EQ. The adjacent
LED illuminates when the EQ is on.
11. GRAPHIC EQ: These sliders control
the output of the frequencies indicated
above each control. The center position of
each control is flat (no boost or cut).
12. POWER ON LED: This LED indicator
illuminates when the POWER switch (#13)
is ON.
13. POWER SWITCH: 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.

Ampeg B2 Specifications