Page 1
FRONT PANEL CONTROLS
1. INPUT JACK The 1/4" phone jack is a high impedance instrument input designed to handle both active and passive
basses in connection with the ACTIVE switch.
2. BLUE JEWEL LIGHT AND POWER SWITCHThe power switch turns on the amplifier and is indicated by the large blue jewel light over the input jack.
3. DRIVE CONTROLThe DRIVE control adjusts the input level to the class A preamps. The DRIVE control serves two pur-
poses. DRIVE can be used to adjust the input sensitivity for the differences in bass pickups. DRIVE will
also change the harmonic content of your sound. Turning the knob closer to 10 will create a more over-
driven tone. The DRIVE will also change the volume of the amplifier, so use it in combination with the
MASTER control to achieve the desired volume.
4. MUTE SWITCHThe MUTE switch turns off the output of the amplifier. A blue LED indicates the MUTE switch is on. The
MUTE switch is ideal for changing basses and silent tuning on stage, since the rear tuner output is never
muted. The mute feature can also be switched with an FS22footswitch.
5. ACTIVE SWITCHFlip the ACTIVE switch to the DOWN position for standard bass pickups. If your bass uses a battery
with an onboard active preamp, put the switch in the UP position. A blue LED indicates the ACTIVE switch
is on.
6. CONTOUR CONTROLThe CONTOUR control provides a variable mid range scoop. When this control is set to FLAT there
is no change to the mid range frequencies. As you turn the contour control clockwise, the mid range is
scooped at the center frequency at 250Hz. When the CONTOUR control is set to maximum the mid-range
is cut by -9dB at 300Hz.
7. BASS AND TREBLE TONE CONTROLSThe BASS and TREBLE controls are custom shaped tone controls designed to deliver punchy lows and
crisp highs for a variety of bass sounds. When a control is turned to the right it boosts the signal and
when turned to the left cuts the signal.
The affected frequencies for the BASS start at 80Hz and can deliver a great deal of volume. Be careful
not to distort the output or overpower the low end of your speakers.
The affected frequency for the TREBLE control begins at 5kHz.
8. SEMI-PARAMETRIC MID SWEEP TONE CONTROLS (LEVEL & FREQ)These three EQs can take some time to learn how to use. Start with the LO MID sweep. The FREQ con-
trol does not function if the GAIN control is set in the center 0 position. To demonstrate, turn the GAIN
to the right for full boost. Now play your bass and turn the FREQ control from left to right and notice the
how the added mids change frequency. Now turn the GAIN to the full left and turn the FREQ control again
and notice the mids disappear at different frequencies. Try this with the MID and HI MID also. As you
can hear, there are many variables, so write down some of the settings for future reference. The mid
sweep system controls can be very effective to fine tune your overall sound.
9. COMPRESSOR (COMP) For some people, a compressor is a new feature. What it basically does is reduce the volume of the
incoming signal as it reaches a preset maximum level. As the COMP knob is turned up (clockwise), the
compressor lets a lower percentage of peak signals to pass through. This percentage is called the com-
pression ratio. When the knob is at the off position (full counter-clockwise) the ratio is 1:1, where all of
the input signal passes through the compressor without being affected. At the MAX setting, the com-
pression ratio is 3:1.
The advantage of a compressor is to the reduce peaks and other sudden loud parts (transients) of your
playing so you can increase your overall volume. For example, in slap bass playing, the plucked notes
can put out peaks that would distort the amplifier at normal playing volumes. If the amps volume was
adjusted for these peaks, the rest of the notes would be too quiet to hear with the band. When the com-
pressor is adjusted to where the LED comes on for loud peaks, the amplifier can be played louder with-
out distortion. Its like having someone re-adjusting the volume of the amplifier to prevent distortion when
the peaks occur.
The compressor circuit in the BXseries is also internally connected to the power amplifier. When the
amplifier reaches peak clipping levels it activates the compressor and reduces the output signal. This
helps prevent the amplifier from clipping and protects the speakers.
10. 9 BAND GRAPHIC EQUALIZERThe 9 band graphic EQ has been designed with center frequencies most requested by professional bass
players. This EQ can be used to fine tune the tonal content of the amps output. Since the graphic EQ is
switchable with either the optional FS22 footswitch or the EQ switch on the front panel, it can be used
during passages of a song when the bass needs to punch through the mix. Musicians that play more
than one bass on stage will also find this useful to get the sounds they desire out of each instrument.
The BLUE LED located above the GRAPHIC EQ IN switch signifies when the graphic EQ is working. NOTE:
When the front panel GRAPHIC EQ switch is off, it cannot be turned on with the footswitch.
11. EFFECTS LOOP SWITCH
The green LED above the front panel EFFECTS switch indicates when the EFFECTS LOOP is active. When
the EFFECTS switch is off the EFFECTS LOOP is bypassed. The signal is still present at the SEND jack,
but the RETURN is not active. The EFFECTS LOOP can also be switched using the optional FS22 footswitch.
NOTE: When the EFFECTS switch is off, the loop cannot be turned on with the footswitch.
12. ELECTRONIC CROSSOVER (BX1200 ONLY)
The electronic X-OVER is used for a bi-amped speaker configuration. When the X-OVER switch is ON,
the BX1200is in bi-amp mode and the BLUE LED above it will be lit. To select the crossover frequency,
rotate the FREQ control knob until the desired frequency is obtained. Low frequencies go to AMP1, and
high frequencies go to AMP2. This allows speakers designed for specific frequencies to be utilized to
their fullest potential, and allows the user even greater control over the tone of thier rig. To start, try set-
ting the FREQ at 300Hz.
NOTE: BI-AMPING does not necessarily deliver the most volume from your system.
1 4 5 8 10 14 15
15 13
16 17 18
9
2 6 8 3 7 7 11 13 2 12
BX1200BX600
