JobSite Systems A30-X12 manual Turn-OnModes, Bridging Two Channels into One

Turn-On Modes

The Turn-On Mode selector switch gives you three options for turning the A30-X12 on and off. See figure 5

Bridging Two Channels into One

The A30-X12's bridging switches allow you to create a more powerful amplifier channel by combining or "bridging" two adjacent channels.

Slide the switch with your fingernail or a 1/8” slotted screwdriver blade.

Figure 5

Constant: The auto turn-on circuitry is off. The front panel master power switch

BUS

12

	BRIDGED
LEVEL				LEVEL
		USE CH 2
		WHEN
	L	BRIDGED
	R		BUS
	L+R
	1

L

R

L+R

2

Slide the bridging switch in the direction of the arrow to bridge two adjacent amplifier channels. Set the controls of the newly bridged pair by using the EVEN numbered channel.

operates the amplifier. In is "On", out is "Off".

Audio Sense: The master switch on the front panel must be in the "On" position. The amplifier is off when there is no audio signal present at either the left or the right input, but the sensing circuitry is on. The turn-on sensing circuitry looks for a tiny amount of audio signal present at any of the audio inputs. If it detects a signal, the amplifier is turned on. Once the audio signal stops, the sensing circuit waits three minutes, then turns the amplifier off.

3-30 Volt AC/DC Trigger Input: The master switch on the front panel must be in the "On" position. The amplifier is off when there is no 3-30V AC or DC voltage detected at the trigger input. Once the sensing circuitry detects a voltage and a line-level audio signal is detected at the input, the amplifier is turned on. Once the voltage stops, the sensing circuit instantly turns the amplifier off. Voltage trigger can be supplied by connecting a 12 Volt AC wall adapter to the switched outlet of your stereo receiver.

DO NOT USE A DC WALL ADAPTER. The long discharge time of the DC adapter’s filter capacitor will delay the turn-off of the amplifier.

When two channels	-	+
are bridged together,
connect speakers to
the two terminals
labeled “Bridged”.

BusMatrix Input Switch Setting

Each channel has a dedicated BusMatrix DIP switch that assigns that channel’s source. To assign a signal from the Main Bus Input, select one of the first three switches, which will give you Left (L), Right

(R)or Mono (L+R). To assign the channel’s dedicated input select the fourth switch. Only ONE switch should be selected to the “ON” position.

MAIN	“OFF” Position	“ON” Position
CASCADE
BUS
BUS		L
INPUT
OUTPUT
L	BUS	R
L		L+R
		1

R

R

5