Dayton Audio MA1240a

Description

The MA1240a from Dayton Audio is a versatile 12-channel amplifier that is ideal for flexible audio distribution. With two stereo bus inputs and one mono input per channel, it offers a wide range of connection options. Thanks to the bridging function, you can combine two channels to increase the power in certain zones. The amplifier delivers an output of 40 watts per channel at 8 ohms in the RMS range and up to 80 watts in the bridge configuration. A wide frequency response from 5 Hz to 72 kHz ensures a clear and comprehensive sound. Practical functions such as automatic on/off and two-color status LEDs simplify use in automated systems.

The MA1240a from Dayton Audio is a 12-channel amplifier that is ideal for flexible audio distribution. With its two stereo bus inputs and one mono input per channel, you can utilize versatile input options. The bridging function makes it possible to combine two channels to amplify the power in certain zones. The amplifier offers a power handling capacity of 40 watts per channel at 8 ohms in the RMS range and up to 80 watts in the bridge configuration. The frequency response covers a wide range from 5 Hz to 72 kHz, ensuring a clear and comprehensive sound. Practical functions such as automatic switch-on and switch-off as well as two-color status LEDs for the operating display make handling in automated systems easier for you.

Technical data


• Channels: 12
• Power handling at 8 ohms (RMS): 40 watts
• Power handling at 8 ohms (bridge): 80 watts
• Frequency response: 5 Hz-72 kHz
• Inputs: 2 stereo bus inputs, 1 mono input per channel
• Outputs: 2 stereo bus outputs

Status LEDs

Each zone has two-color LEDs that indicate the operating status

Stereo and mono inputs

Two bus inputs can be routed to each channel or individual inputs can be used per channel

Bypassable outputs

Two channels can be bridged to increase the total power for that zone with a single switch

Inputs and outputs

Two common or BUS inputs feed audio signals from standard line-level audio sources into one or all channels. Each of the twelve channels has its own input and independent level adjustment to provide further flexibility. By simply flipping a switch, two channels can be bridged to increase the overall output for that zone. This is useful when additional power is required in certain areas.

Practical functions

Manual, automatic on/off switching or 12 V input switching facilitate integration into automated systems. For quick and easy troubleshooting, each channel or zone pair has a two-color LED to indicate operating status. Use 14-18 AWG stranded wire with two conductors and Phoenix connectors.

Connection options

Front page

• Power supply: The mains switch on the front switches the amplifier on and off. When the switch is on and the LED indicator is red, the amplifier is in standby mode. The remote power switch (on the back) is either in the "Trigger" or "Auto" position. When the LED indicator lights up blue, the amplifier is fully active. The main power switch switches the amplifier off, regardless of which power supply mode has been selected.
  

• Zone status indicators: Each channel or zone pair has a two-color LED that indicates the operating status. These indicators allow for quick and easy troubleshooting of the system. If the circuit detects that a channel needs to be turned off due to excessive heat or low impedance (short circuit), only the affected channels will be turned off, causing the zone LED to glow red. The remaining zones remain in operation and retain the blue LED status. As soon as the condition for the zone in question has been rectified, the status LED lights up blue again.
  

Back

• BUS line inputs/outputs: The MA1240a has two common or BUS inputs that receive audio signals from standard line-level audio sources and send them to one or all channels. The BUS line outputs are looped directly through so that the BUS inputs can be routed to other amplifiers. Make sure to use high-quality RCA cables with low impedance, shielding and high-quality connectors.
• Remote switch: This switch is used to select the switch-on pulses that put the amplifier into standby mode. The "Trigger" setting relies on a 3-30 V AC/DC voltage flowing into the trigger input to activate the amplifier. The "Auto" setting detects a signal at the RCA line level inputs and automatically sets the amplifier to standby mode. The "On" setting puts the amplifier permanently in standby mode so that it can be controlled via the main switch on the front panel. In "Auto" mode, the amplifier takes about 15 minutes to return from standby to standby mode.
  
• Trigger I/O: The trigger input is a handy feature when connecting the amplifier to an automated audio system. The 3.5 mm mini-jack socket accepts a 3-30 V AC/DC output from another device or from a separate power supply. When the trigger input is activated, the amplifier switches from standby to ON mode. If the MA1240a is used with a receiver without a trigger output, the voltage can come from a 12 V plug-in power supply (3.5 mm jack plug with positive pole), which is connected to the receiver's switch socket and the trigger input. The MA1240a can also provide an output trigger voltage (12 V DC at max. 500 mA) for switching other devices in the audio system on and off. When the amplifier is switched off (standby mode), the voltage drops to zero.
• Channel gain control: Each channel has its own independent level setting. This allows the output level of each speaker to be perfectly matched to its range. This function can also be used to limit the maximum audio level in a specific range.
• Bypass switch: By simply flipping a single switch, two channels can be combined to increase the total output power. This is useful if additional power is required in certain areas.
• Input selection switch: Each channel can provide the source of many inputs. The three main inputs are BUS 1, BUS 2 and LINE IN. The selection for these inputs is made via the input selection switch assigned to each channel. Select the desired source signal input. Set the input selection switch to BUS 1 (plays the source connected to the BUS 1 input), BUS 2 (plays the source connected to the BUS 2 input) or LINE IN (plays the source connected to the LINE IN input of this channel).
• Speaker output terminals: The MA1240a uses high quality Phoenix connectors (5 mm pitch) for the speaker connections. Use 14-18 gauge stranded wire with two conductors. Make sure that at least 5 cm of each conductor is separated. Remove 6 mm of insulation from each conductor. Connect the appropriate conductor to each screw terminal, ensuring correct polarity. Also ensure that the speaker wiring is correct when bridging channels.
• Single channel output: All twelve channels have their own dedicated input, which enables the connection of audio sources in addition to the common BUS inputs. This is useful when the MA1240a is used with an audio matrix switcher.
• AC voltage switch: The device is factory-set for operation with 120 V in the USA. Simply connect the supplied IEC power cable to a wall socket. For operation with 230 V, set the voltage selector switch to the 230 V position. When operating with 230 V, the internal fuse in the IEC socket should also be replaced. For most 230 V applications, a separate mains cable is required, which is not included in the scope of delivery.
• IEC mains connection: The device is supplied with an IEC socket that allows the mains cable to be removed. This allows the mains cable to be flexibly adapted to different countries. The IEC socket also contains the main fuse holder. Connect the mains cable supplied with the amplifier to the amplifier and the wall socket or a suitable surge protector.

Technical data

• Channels: 12
  
• Rated load capacity (RMS): 40 watts
• Rated load capacity (MAX): 80 watts
• Frequency response: 5 Hz - 72 kHz
• Input sensitivity: 380 mV
• Signalrauschabstand, A-bewertet: <105 dB
• Total harmonic distortion: 0.09 %
• Inputs: 12 individual inputs, 2 stereo bus inputs.
• Outputs: 2 stereo bus outputs
  
• Power supply: 120 - 230 VAC
• Standby consumption: 0.264 watts
• Dimensions: 42.6 cm W x 36.2 cm D x 10.2 cm H
• Weight: 15.4 kg

Product details

• Model number MA1240a
• Color black
• Product height 102 mm
• Product width 424.18 mm
  
• Product depth 356-25.4/102 mm
• Amplifier type Multi-zone amplifier
• Output power 40 watts per channel RMS at 8 ohms, 80 watts per channel RMS at 8 ohms (bridged)
• Input impedance 18 kiloohms
  
• Signal-to-noise ratio 105 dB A-weighted
• THD at rated power 0.005 % THD 20 Hz-20 kHz at 30 W (8 Ohm) 0.010 % THD 20 Hz-20 kHz at 80 W (8 Ohm) (bridged)
• Frequency response 5 Hz to 72 kHz
• Efficiency 63 %
• Voltage requirement 120/230 VAC 60/50 Hz
• Auto-on sensitivity 13.7 mV
• Stand-by power consumption 115 V, 0.264 W

Special features

• Multi-stage protective circuit
• Suitable for rack mounting
• Independent gain control of the channels
• 12 channels (6 stereo zones)
• Individual channel inputs (plus BUS 1 & 2)