5
4
5
11
13
3
6
12
10
8 9
2
1
7
6. NOMENCLATURE AND FUNCTIONS
[Front]
1. Power switch
Pushbutton alternately switches the AC power
on and off.
2. Power indicator LED
The green LED lights when the power switch is
"ON".
3. Lowpass filter slope selection switch
This switch sets the lowpass filter's per octave
attenuation for either 6 dB or 12 dB.
4. Peak indicator LED
The peak indicator LED lights when either the
input or the output level reaches 3 dB below
clipping.
5. Input level control
This control adjusts the input gain by ±12 dB to
allow the use of a wide range of input sources.
To insure the best S/N ratio possible, adjust this
control so that the peak LED flashes only
occasionally.
6. Lowpass filter control
This is a shelving-type filter that provides a 12
dB or 6 dB per octave roll off above 2.5 kHz and
up to 30 kHz. Its main purpose is to stop high
frequency noise, oscillation, and certain types of
RF interference from damaging tweeters. It is
also useful in reducing excessive background
noise, such as that produced by old phonograph
records.
7. Equalizer sliders
These sliders are adjusted to tune or equalized
the overall frequency response of a sound
system.
8. Equalizer indicator LED
The indicator LED turns on whenever the
equalizer IN/OUT switch is "IN".
9. Equalizer IN/OUT switch
Equalizer switch puts the input signals either in
circuit or out of circuit of the equalizer. The
"OUT" position provides flat audio response no
matter what the positions of the equalizer sliders
and the filter (LPF/HPF) control.
10. Security cover mounting hole
This hole is used to mount the supplied security
cover with two screws to avoid accidental
changes in set position of control knobs and
switches.
11. Filter IN/OUT switch
Pressing this switch while equalizer indicator
lights provides the frequency response set for by
the lowpass-and highpass-filter control. Press
the switch again to disable the lowpass-and
highpass-filter control.
12. Filter indicator LED
The filter indicator LED lights when the filter
switch is "IN".
13. Highpass filter control
This shelving-type filter provides an 12 dB per
octave rolloff between 300 Hz and 15 Hz. It is
especially useful for reducing stage or turntable
rumble, AC hum, wind noise, and other subsonic
components that waste amplifier power and tax
speakers.
