Stewart Audio AV25-2 RS232 - Manual (Page 8)

3.2.1 Indicators
The AV 25 has 4 rear panel LED indicators. The first is the power indi-
cator which will illuminate when power is supplied to the amplifier. The
final light is the signal present LED which will illuminate when signal is
detected on either one of the input connection channels. The final 2
LED indicators are the “Clip” indicators, one for each channel. These
lights will indicate that the input signal is too “hot” and will sound dis-
torted when amplified. To fix this, the gain should be reduced at the
preamp or mixer level.
3.2.2 Controls
All AV25-2-RS232 controls are located on the rear of the unit. There is
no power switch so the AV25-2-RS232 will turn on whenever power is
supplied to it. Signal Sense Technology (SST ) will power up the am-
plifier from sleep when a signal is detected. After 5 minutes without
an input signal the amplifier will go into sleep mode.
The rear panel contains two individual channel volume knobs . The am-
plifier is set to run off of a line-level source and the level should be ad-
justed for optimum performance. To adjust this knob, you will need a
small flat-head screwdriver. While a typical program source level is
present, spin the rotary knob as far clockwise as you can without hear-
ing distortion or without the “Clip” indicator illuminating. If the signal is
distorting and the knob is all the way counter-clockwise, adjust the gain
down at the source level.
3.2.3 RS232 Controls
Please refer to section 4.
4 RS232 Control
4.1 RS232 Overview
The AV25-2-RS232 contains built-in RS232 control over the master vol-
ume and master muting of the amplifier. Through the use of RS-232
commands, this interface will control an internal digital potentiometer
and mimic the standard 10KΩ potentiometer typically put into a wall-
plate. The available commands will mute, increase or decrease the vol-
ume, or set the volume to a specific value. All communication should
be done at 9600 baud.
4.1 RS232 Connection
4.2 Muting and Memory
When the device is muted, it will save the current volume so that when
unmuted it will return to the previously set volume.
All volume and mute settings are saved into an internal memory so it
will recover within milliseconds from a power reset (compatible with
amplifiers with sleep states).
TX
RX
1
2
3
4
5
6
7
8
9
DB9 F
em
ale
(Rear)
NOTE - TX and RX
labelings are relative to
the controller