Ampeg B2R - User Manual

1. 0DB (INPUT): The signal output from an instru-
ment (active or passive) or a line level signal may
be connected here by means of a shielded instru-
ment cable.
2. 15dB PAD:This switch, when depressed, atten-
uates the input signal by 15dB. Attenuation allows
the Gain control (4) to be used over a larger por-
tion of its range. If clipping is indicated with the
Gain control near minimum, attenuation is needed.
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 LEDflashes frequently with the gain
at a low setting, use the 15dB Pad (2) to attenuate
the input signal and readjust 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 con-
trol. 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 frequency
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 (23,23;26) are not affected by the
Master control.
9. LIMITER: The 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 maximum 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 Limit
LED (10) 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. LIMIT LED: This LED will flash when the inter-
nal limiter circuit is activated.
11. EQON SWITCH: Depress this switch to acti-
vate the Graphic EQ. The EQON LED (12) illumi-
nates when the EQ is on.
12. EQ ON LED: This LEDilluminates when the
graphic EQ is activated.
13. 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).
14. POWERON LED: This LED indicator illumi-
nates when the POWER switch (15) is ON.
15. 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.
B-2R front panel:

Ampeg B2R Specifications

General

Type	Bass Amplifier Head
Preamp	Solid State
Effects Loop	Yes
Power Output	350W @ 4 ohms
Power Amp	Solid State
EQ	3-band
Inputs	1 x Instrument
Outputs	1 x 1/4"

Summary

Ampeg B-2 R Front Panel Controls

Input Signal Connections

0dB INPUT: Connects instrument or line level signal via shielded cable. 15dB PAD: Attenuates input signal by 15dB.

Signal Clipping Indicators

PEAK LED: Flashes when signal approaches clipping. Adjust Gain to make it flicker.

Gain and Tone Controls

GAIN: Input level control. BASS: Low frequency control (±8dB @ 50Hz). ULTRA-MID: Midrange control. TREBLE: High frequency control (±12dB/+19dB @ 5kHz).

Master Output and Limiter

MASTER: Controls overall output level. LIMITER: Engages Optocoupler Limiter to prevent distortion at high volumes.

Graphic EQ and Status LEDs

EQON SWITCH: Activates Graphic EQ. EQ ON LED: Indicates EQ activation. GRAPHIC EQ: Sliders for frequency output control.

Power On Indicator and Switch

POWERON LED: Illuminates when the amplifier is ON. POWER SWITCH: Heavy-duty rocker switch to turn the amplifier on/off.

Ampeg B-2 R Rear Panel Connections

Cooling and Protection

FAN: Temperature controlled fan for cooling. FUSE: Protects unit from overload/surges; replace with identical type.

Power Input and Speaker Outputs

AC LINE IN: Connects the supplied AC power cord to a grounded outlet. SPEAKER OUTPUTS: Connects amplifier to speakers (≥4 ohm impedance).

Preamp and Effects Loop

POWER AMP IN: Bypasses B2R preamp, feeding signal directly to power amp. PREAMPOUT: Post-EQ signal output for external devices.

External Effects Integration

EFFECTS RETURN: Connects external effects device output into Master section. EFFECTS SEND: Sends post-EQ signal to external effects input.

Balanced Output Features

-20dB SWITCH: Adjusts Balanced Output level for mixer mic inputs. PRE/POST SWITCH: Selects Pre or Post EQ for Balanced Output signal.

Balanced Line Output

BALANCED OUTPUT: XLR connector for balanced preamp output to mixers, consoles, or external amps.