Sonodyne SBA 250P - Manual (Page 8)

FRONT PANEL CONTROLS
Page 6
SMA/ SBA SERIES
Front panel: The functions of the controls and indicators on the SMA 250/ SBA 250P are as follows:
1. POWER SWITCH: Press the switch to up for power on and down for power off. At start-up (turn-on),
2. ON INDICATOR: This LED will illuminate RED and indicates that the amplifier is on and receiving mains
power.
3. SIGNAL INDICATION: This green LED indicates the presence of the signal.
4. MASTER LEVEL CONTROL: The master level pot controls the overall output level of the amplifier
depending on the levels set for the individual input channels as detailed below. Start with the control
set to level '0' and turn clockwise until the desired output level of the amplifier is reached.
(Note: SBA 250P has this level control on the rear panel. It is a recessed control without any external
knob. You can set it to the desired level using a simple cross head screw driver. The output level can be
increased by rotating this control clockwise from MIN (-) position to MAX (+) position.)
5. TREBLE CONTROL: Keeping this control in the centre position will give an overall flat treble response. If
this treble control is moved in a clockwise direction will provide up to 9 dB of treble boost @ 10 kHz
And if it is moved in a counter-clockwise direction from 0 dB then it will provide up to -9 dB of treble
cut @ 10 kHz. We recommend to keep this in Centre '0' dB position for a normal initial operation.
(Note: This feature is not present for SBA 250P)
6. BASS CONTROL: Keeping this control in the centre position will give an overall flat bass response. If this
bass control is moved in a clockwise direction will provide up to 12 dB of bass boost @ 100 Hz, and if
it is moved in a counter-clockwise direction from '0'dB then it will provide up to -12 dB of bass cut @
100 Hz. We recommend to keep this in Centre '0' dB position for a normal initial operation.
(Note: This feature is not present for SBA 250P)
7. MICROPHONE/LINE INDIVIDUAL LEVEL CONTROLS: The SMA 250 features 4 universal mic/line input
controls labeled Ch 1 through to Ch 4 and should be adjusted to provide the required level mix for each
individual channel. Initially keep these controls at level '0' and rotate the controls in clockwise
direction to achieve the desired mix level for each channel individually.
(Note: This feature is not present for SBA 250P)
NOTE: You should always ensure that the fan grille and Front ventilation slots are kept clean and free from
the build up of dust and lint. This will ensure longer operation of your amplifier and reduce the possibility of
it prematurely going into thermal shutdown mode. See the section “Installation - Cooling “ on page 9 for
recommended cooling procedures.