Ampeg B4R - Manual (Page 7)

7
The Rear Panel – Con’t.
32. FOOTSWITCH: Connect a two button footswitch to this
jack for remote Mute and EQ On/Off control. On the stereo
1/4” plug, the tip controls Mute and the ring controls EQ
On/Off. When a footswitch is connected, the Mute switch
(#3) can still be used; however, the EQ switch (#12) is dis-
abled.
33. BIAMP HIGH/LOW OUTPUTS: When using the amplifi-
er in the biamp mode, the Biamp High Out jack carries the
high frequency signal and the Biamp Low Out jack carries
the low frequency signal. (See pages 8 and 9.)
34. LINE OUT LEVEL: This controls the strength of the sig-
nal at the Line Out jacks (#37,38) and works independently
from the Master control (#14).
35. LINE OUT PRE/POST SWITCH: The signal at the Line
Out jacks can be set to either Pre or Post EQ with this switch.
With the switch in the OUT position, the signal at the jacks
will be Pre-EQ. This is a direct output not affected by any
preamp tone settings. With the switch IN, the signal is Post-
EQ and is controlled and modified by the tone controls,
Graphic EQ and the effects loop.
36. LINE OUT GROUND LIFT: This switch disconnects the
ground pin of the line Out XLR jack (#37), which may help
reduce residual hum and buzz sometimes picked up in line out
signal cables. The ground is lifted when the switch is depressed.
37, 38. LINE OUT JACKS: These jacks supply a pre-
Master, line level signal for connection to a house mixing
board, recording console or external amplifier(s). The XLR-
type jack (#37) provides a balanced signal; the 1/4” jack
(#38) provides an unbalanced signal. The signal level at
these jacks is controlled by the Line Out Level control (#34)
and is governed by the Pre/Post switch (#35).
39. EFFECTS LOOP RETURN: When using external
effects, connect the effect’s output into this jack using a
shielded instrument cable.
40. EFFECTS LOOP SEND: When using an external signal
processor, connect this jack to the input of the effect using a
shielded instrument cable.
41. TUNER OUT: This jack is provided for connection to an
electronic tuner and is always “live,” even when the Mute switch
(#3) is engaged, allowing for “silent tuning” as well as a monitor
feed which remains active when the house mix is muted.
B4R Bass Amplifier
IMPORTANT: This unit employs forced air cooling by means
of an internal fan. The rear and side ventilation slots must
remain unobstructed when operating this amplifier. When
mounting the unit in a rack make sure there is ample room
for proper air circulation. The rack must be constructed and
positioned in such a manner to allow proper air flow and the
exhausting of hot air away from the rack at all times.
Yearly cleaning and maintenance by an Authorized Ampeg
Service center will help keep the amplifier running cool and
extend its useful life.