BX-25/50 Bass Amplifier
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1: 0dB INPUT: Connect your bass here if it has “normal” pickups
and no active electronics. This sends a full strength signal into the
amplifier. If your bass has active electronics or high output pickups,
or if the amp sounds like it’s distorting try the -15dB Input (#2).
2: -15dB INPUT: Connect your bass here if it has active electron-
ics or high output pickups. The output signal will be attenuated by
15dB to keep it from overloading the amplifier’s input stages.
3: GAIN: This serves as the input signal level control, allowing you
to set the amplifier for the best signal to noise ratio.
4: CONTOUR SHAPE: This control is only active when the
Contour Active switch (#5) is pressed in. The setting of this control
shifts the frequency where the contour effect is centered, giving
you a wide variety of tonal variations, from a studio “V”-shaped
tone to a more “live”, more present sound.
5: CONTOUR ACTIVE: When this pushbutton switch is pressed in
the Contour Shape control (#4) is activated and the sound of your
bass is affected by the setting of the control. Pressing the switch in
a second time releases it, deactivating the Shape control.
6: LOW: Adjust the output level of your low-bass tones with this
control. The center position is “flat” (no boost or cut). Turning the
control to the left reduces the output level of the low frequency
tones; turning it to the right increases their level. This control allows
a 28dB range of boost or cut at 60Hz.
7: LOW MID: Adjust the output level of your lower midbass tones
with this control. The center position is “flat” (no boost or cut).
Turning the control to the left reduces the output level of the lower
midbass tones; turning it to the right increases their level. This con-
trol allows a 15dB range of boost or cut at 400Hz for the BX-25;
150Hz for the BX-50.
8: HIGH MID: Adjust the output level of your upper midbass tones
with this control. The center position is “flat” (no boost or cut).
Turning the control to the left reduces the output level of the upper
midbass tones; turning it to the right increases their level. This con-
trol allows a 18dB range of boost or cut at 1kHz.
9: HIGH: Adjust the output level of your high frequency overtones
with this control. The center position is “flat” (no boost or cut).
Turning the control to the left reduces the output level of the high
frequency overtones; turning it to the right increases their level.
This control allows a 33dB range of boost or cut at 10kHz.
10: MASTER LEVEL: The output level of the internal speaker,
headphone jack and extension speaker are governed by the set-
ting of this control. At the full left position there will be no output;
rotating the control to the right increases the output volume level.
11: LIMIT: When a power amplifier reaches maximum output lev-
els it may begin to “clip” its output signal which generates poten-
tially speaker-damaging distortion. The BX-25/50 has a special
APM (Automatic Power Maximizer) limiting circuit which helps
minimize this problem by monitoring the power amplifier’s output
signal, keeping it below clipping. This feature insures you that the
sound from your amplifier remains clean and pure even at full
power. The APM indicator will only light when the amplifier is near
clipping; flashing at peak playing levels is acceptable, however if
the light remains on constantly reduce the Master Volume until the
light flashes.
12: HEADPHONES: For private practice sessions, plug a pair of
stereo headphones into this jack. The internal speaker is discon-
nected whenever headphones are being used.
13: EXTENSION SPEAKER: You may connect the BX-25/50 to
an external speaker with a rated impedance of 4 ohms or more
using this jack. The internal speaker is disconnected from the
amplifier when the Extension Speaker jack is used.
14: ON LED: The word “ON” will glow when you turn the amplifier
on showing you that the amplifier is activated and ready to play.
15: POWER: This heavy duty rocker type switch is used to turn the
amplifier ON in the up position, OFF in the down position. The ON
LED (#14) works with this switch as a visual indicator.
16: POWER CORD: (Rear panel, not shown) This heavy duty,
grounded, three wire power cord is to plugged into ONLY a
safely wired, grounded 120 volt, 60 cycle AC power outlet. DO
NOT attempt to defeat the ground connection of this cable!
If your BX-25/50 was purchased outside of the United Stated,
see the unit’s rear panel for its power rating and follow the
above guidelines.
WARNING: DO NOT attempt to use head-
phones in the Speaker jack! Permanent
hearing damage could result!
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