SVT-4 PRO Bass Guitar Amplifier
The Front Panel
1. INPUT: The signal output from an
instrument (active or passive) may be
connected to this 1/4" input by means
of a shielded instrument cable.
2. TUNER OUT: This jack supplies the only
live output when the mute switch  is
engaged. This allows for silent tuning
through an electronic tuner or killing the
house send with a monitor mixer send
still active. In addition, this jack may
also be used as a –6 dB input (when
not connected to a tuner).
3. MUTE: Press this switch in to mute
all outputs except the tuner outs [2, 49].
The footswitch may also control mut-
ing if the mute switch  on the front
panel is left in the “out” position. (The
front panel switch is still active with the
footswitch connected. This is excellent
for tuning your bass with an electric
tuner without having to adjust any levels
to turn down the sound). The peak LED
 will illuminate when this switch is
4. –15 dB: Press this switch in to reduce
the input signal by 15 dB and
compensate for higher output sources.
This attenuation is suited for use with
basses that have active electronics or
high-output pickups. Use this pad if you
notice that the peak LED  comes on
regularly. It will reduce the chance of
overdriving the preamplifier stage and
allow more usable range and fine
adjustment of the gain control.
5. GAIN: This varies the amount of signal
driving the preamplifier. If a small
clockwise rotation from minimum leads
to overloading and the peak LED 
illuminating, try engaging the –15 dB
pad . This will give more usable range
with the gain control.
6. PEAK LED: This red warning LED will
come on if the input signal is too high,
the gain control  is set too high, or
there is too much boost from the bass
, midrange  and treble 
controls. If it comes on regularly, even
when these controls are low, try
engaging the –15 dB pad .
7. COMPRESSION: This controls the
amount of signal compression. At the
fully counterclockwise position there is
no compression; at the fully clockwise
position the compression ratio is 10:1.
The sonic effect of compression is
reduced dynamics, increased sustain
and a more consistent output level
regardless of how light or hard the
strings are played. The compressor is
very transparent – that is, there is very
little effect on the tone of your
8. ULTRA HI: This switch, when engaged,
enhances the amount of high frequency
output by 6 dB at 5 kHz.
9. ULTRA LO: This switch, when engaged,
enhances the amount of low-end output
by 2 dB at 40 Hz and –10 dB cut at
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