Instruction manual

Commercial Audio Series Amplifiers
page 6
Operation Manual
1 Welcome
1.2 Front Panel Controls and Indicators
(280A shown; other models are fairly similar)
A. Master Volume Controls
One per output channel. Detented potentiometer with
knob.
B. Output Signal Presence Indicator
Green LED, one for each output channel, illuminates
when output signal level exceeds 100 mV (45 dB below
full power) from the 4-ohm tap.
C. Clip Indicator
Red LED, one per output channel, illuminates at thresh-
old of audible distortion.
D. Power Indicator
Blue LED indicates power on.
E. Power Switch
Pushbutton on-off switch. The power switch does not
affect the 24V DC auxiliary power input (letter “H” on
next page).
F. Tone Controls
Bass and Treble non-detented potentiometers on each
channel. Bass ±10 dB at 100 Hz, Treble ±10 dB at 10
kHz.
B
T
B
T
Figure 1.1 Front Panel Controls and Indicators
(280A shown)