Behringer 1273 2-Channel Microphone Preamplifier and Equalizer User Manual

1. Introduction

The Behringer 1273 is a 2-channel microphone preamplifier and equalizer designed to provide high-quality audio signal processing. It features all-discrete Class A circuitry, transformer-balanced XLR/combo jacks, and custom-made Midas transformers, delivering up to 80dB of gain. This unit is suitable for professional studio environments and offers versatile tone shaping capabilities.

Key features include:

• 2-channel Mic/Line/Instrument Preamp with 3-band EQ
• Custom Midas Transformers for authentic sound
• Highpass Filter for noise reduction
• Tone Switch to adjust transformer impedance for various microphones

Figure 1: Angled view of the Behringer 1273 unit, showcasing its front panel controls and robust build.

2. Setup

This section details the steps required to connect your Behringer 1273 preamplifier to your audio system.

2.1 Unpacking and Inspection

Carefully unpack the unit and inspect it for any signs of damage during transit. Ensure all included components are present:

• Behringer 1273 2-Channel Smart Microphone Preamplifier with 3-Band Equalizers
• Power Cable

2.2 Power Connection

1. Ensure the unit's power switch is in the OFF position.
2. Connect the supplied power cable to the AC INPUT on the rear panel of the 1273.
3. Plug the other end of the power cable into a suitable AC power outlet.

2.3 Audio Connections

The Behringer 1273 offers comprehensive input and output options on its rear panel.

Figure 2: Rear panel of the Behringer 1273, showing AC input, Line Out, Return, Send, and Mic In connections for both channels.

• MIC IN (XLR): Connect your microphone to these XLR inputs.
• LINE OUT (XLR): Connect these XLR outputs to your audio interface, mixer, or other recording equipment.
• SEND/RETURN (1/4" TRS): These jacks allow for inserting external effects processors into the signal path of each channel. Connect the Send to the input of your effect unit and the Return to the output of your effect unit.
• LINE IN (1/4" TRS): Connect line-level sources to these inputs.

On the front panel, each channel also features a combo jack for MIC/LINE input and a 1/4" TS INST input for direct instrument connection.

3. Operating Instructions

This section provides an overview of the controls and their functions on the Behringer 1273.

Figure 3: Front panel of the Behringer 1273, highlighting the controls for each of the two channels.

3.1 Front Panel Controls (Per Channel)

• MIC/LINE Input: Combo jack for XLR microphone or 1/4" TRS line input.
• +48V Button: Engages phantom power for condenser microphones. Activate only when a condenser microphone requiring phantom power is connected.
• V Button: This button is likely related to voltage or impedance settings, potentially interacting with the Tone switch for further sound optimization.
• TONE Switch: Adjusts the transformer impedance to optimize the sound for different microphone types, such as ribbon or vintage microphones.
• INSERT Button: Activates the insert send/return loop for external effects.
• INST Input: 1/4" TS input for direct connection of instruments (e.g., guitar, bass).
• GAIN Knob: Controls the input gain for the microphone, line, or instrument signal. Adjust to achieve an optimal signal level without clipping.
• LOW EQ Knob: Adjusts the low-frequency band. Features selectable frequencies (e.g., 35 Hz, 60 Hz, 110 Hz, 220 Hz) and cut/boost control.
• MID EQ Knob: Adjusts the mid-frequency band. Features selectable frequencies (e.g., 360 Hz, 700 Hz, 1.6 kHz, 3.2 kHz) and cut/boost control.
• HIGH EQ Knob: Adjusts the high-frequency band. Features selectable frequencies (e.g., 4.8 kHz, 7.2 kHz, 10 kHz, 12 kHz) and cut/boost control.
• HI PASS Filter Knob: Engages a high-pass filter with selectable cutoff frequencies (e.g., 50 Hz, 80 Hz, 160 Hz, 300 Hz) to remove unwanted low-frequency rumble.
• EQ Button: Engages or bypasses the equalizer section for the channel.
• LEVEL Knob: Controls the output level of the channel.
• LEVEL Meter: LED indicators display the output signal level, helping to prevent clipping and ensure proper gain staging.

3.2 Global Controls

• POWER Button: Turns the unit ON or OFF.
• POWER Indicator: Illuminates when the unit is powered on.

Figure 4: A user adjusting the controls on the Behringer 1273, demonstrating typical operation in a studio setting.

4. Maintenance

Proper maintenance ensures the longevity and optimal performance of your Behringer 1273.

• Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Avoid abrasive cleaners, solvents, or waxes. Do not spray liquids directly onto the unit.
• Ventilation: Ensure adequate ventilation around the unit to prevent overheating. Do not block ventilation openings.
• Storage: When not in use for extended periods, store the unit in a cool, dry place, away from direct sunlight and extreme temperatures.
• Power Cord: Regularly inspect the power cord for any damage. Do not operate the unit with a damaged power cord.

5. Troubleshooting

This section addresses common issues you might encounter with your Behringer 1273.

5.1 No Power

• Check Power Cable: Ensure the power cable is securely connected to both the unit and the AC outlet.
• Check Power Outlet: Verify that the AC outlet is functional by plugging in another device.
• Power Switch: Confirm the POWER button on the front panel is engaged.

5.2 No Sound Output

• Input Source: Ensure your microphone or instrument is properly connected to the correct input (MIC/LINE or INST).
• Output Connections: Verify that the LINE OUTs are connected to your audio interface or mixer's inputs.
• Gain and Level: Check that the GAIN and LEVEL knobs are turned up sufficiently.
• Phantom Power: If using a condenser microphone, ensure the +48V button is engaged.
• EQ Bypass: Ensure the EQ button is not engaged if you suspect the EQ settings are causing an issue.
• Insert Loop: If an external effect is connected via the SEND/RETURN loop, ensure it is functioning correctly or bypass it using the INSERT button.

5.3 Distorted Sound

• Gain Staging: Reduce the GAIN knob. The LEVEL meters should not consistently show red (clipping).
• Output Level: Reduce the LEVEL knob. Ensure the input of the next device in your signal chain is not overloading.
• Cable Integrity: Check all audio cables for damage or loose connections.

6. Specifications

Detailed technical specifications for the Behringer 1273.

7. Warranty

The Behringer 1273 comes with a 2-Year Warranty. For detailed terms and conditions, please refer to the official Behringer warranty documentation or visit their website.

8. Support

For further assistance, technical support, or service inquiries regarding your Behringer 1273, please visit the official Behringer website or contact their customer support. You can find more information and resources at the Behringer Store on Amazon.