1. INPUT: Connect your instrument here by
means of a shielded instrument cable.
2. MUTE: This switch, when depressed,
mutes the output of the amplifier to the
speakers. This is excellent for tuning your
bass with an electronic tuner without hav-
ing to adjust any levels or turn down your
stage volume. When a footswitch is used
(see #19, rear panel) this switch is dis-
abled. The Tuner Out and Bal. Out jacks
(#21 and #27) are unaffected by the Mute
switch.
3. PAD: This switch, when depressed,
attenuates the input signal by 15dB.
Attenuation allows the Gain control (#5) to
be used in a more usable (higher) position.
If clipping is indicated with the Gain control
way down, attenuation is needed.
4. PEAK/MUTE LED: This LED flashes
when the signal level into the preamp
(excluding the graphic EQ) approaches clip-
ping. Adjust the Gain control (#5) until a
strong signal from your instrument causes
this LED to flicker. When the Mute function is
engaged this LED remains fully illuminated.
NOTE: If the LED flashes frequently with
the gain at a low setting, use the Pad
switch (#3) to attenuate the input signal
and readjust the Gain (#5).
5. GAIN: Use this control to adjust the input
level of the amplifier. For the best signal-to-
noise set this control so the Peak/Mute
LED (#4) flashes when you strike a string
fairly hard.
6. BASS: This is the primary low frequency
control. It allows for a range of 8dB of boost
or 18dB of cut at 50Hz.
7. ULTRA-MID: The primary midrange
control. Rotate the control to the left of cen-
ter for a “contoured” sound (more distant,
less midrange output) or to the right of cen-
ter for a sound which really cuts through.
8. TREBLE: This is the primary high fre-
quency control. It allows for a range of
12dB boost or 24dB of cut at 5kHz.
9. MASTER: Set the overall output level of
the amplifier with this control. The Effects
Loop and Balanced Out (#23-27) are not
affected by the Master control.
10. LIMIT: The BA500 uses an internal
Optocoupler Limiter to assist in keeping the
power amplifier’s output “clean” at extreme
volume levels. (All amplifiers may begin to
clip their output signals as they approach
maximum output levels, resulting in poten-
tially damaging distortion.) To engage the
Limiter, depress the Limit switch. The adja-
cent LED illuminates whenever the limiter
circuit is activated. This indicates that the
amplifier is nearing full output and the lim-
iter 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.
11. EQ ON: Depress this switch to activate
the Graphic EQ. The adjacent LED illumi-
nates when the EQ is on. When a
footswitch is used (see #19, rear panel)
this switch is disabled.
12. GRAPHIC EQ: These sliders control
the output of the frequencies indicated
below each control. The center position of
each control is flat (no boost or cut).
13. ON LED: This LED indicator illuminates
when the POWER switch (#14) is ON.
14. POWER: 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.
