Output Level, Phantom Power | Audio-Technica AT-MX351 guide

The preamplifier gain may be reduced further, allowing the SmartMixer to accept line-level sources. Changing the settings of the internal switches designated by “SW3,” “SW9,” “SW15” and “SW21” will cause an input reduction of 50 dB for channels 1, 2, 3 and 4 respectively.

Note that the appropriate internal switches can be used in combination for a total sensitivity reduction of up to 60 dB for each channel.

Output Level

The SmartMixer’s output is factory set at line level. Should mic-level output be desired, simply unplug the unit, remove the top cover and locate the switch on the circuit board marked “SW26” (Figs. 4 and 5, page 11). Changing the setting of this switch will cause a 50 dB reduction in output.

Phantom Power

Each of the SmartMixer’s inputs supplies +48V DC phantom power. Should it be required to disable the phantom power, simply unplug the unit, remove the top cover and locate the switches designated on the circuit board by “SW1,” “SW7,” “SW13” and “SW19” (Figs. 4 and 5, page 11). Changing the settings of these switches will disable phantom power on channels 1, 2, 3 and 4, respectively. Note that, although they do not require phantom power for operation, most balanced-output dynamic microphones can be used without disabling the SmartMixer’s phantom power.

Output Level LED Meter

The Output Level LED meter is factory set to indicate RMS output. Should peak output indication be desired, simply unplug the unit, remove the top cover and change the setting of the switch designated on the circuit board by “SW27” (Figs. 4 and 5, page 11). “Zero” (0) level is factory-calibrated at +4 dBm into 600 ohms.

Summary of Internal Controls

Function	Ch 1	Ch 2	Ch 3	Ch 4	Output
48V Phantom Power	SW1	SW7	SW13	SW19
10 dB Input Atten.	SW2	SW8	SW14	SW20
50 dB Mic/Line Atten.	SW3	SW9	SW15	SW21	SW26
Limiters (on/off)	SW4	SW10	SW16	SW22
“Off” Atten. Range	SW5	SW11	SW17	SW23
Preamp Output Gating	SW6	SW12	SW18	SW24
Limiter Thresholds	VR2	VR5	VR8	VR11
“Off” Atten. Adjustment	VR3	VR6	VR9	VR12
NOMA	--	--	--	--	SW25
Meter RMS/Peak	--	--	--	--	SW27

Figure 3. Summary of internal controls

AT-MX351 specifications

The Audio-Technica AT-MX351 is a versatile mixer that has gained a strong reputation amongst audio professionals for its performance and utility. Designed for various applications, from live sound to permanent installation, the AT-MX351 boasts features that enhance audio quality and ease of use.

One of the standout features of the AT-MX351 is its ability to handle multiple audio sources with ease. It features three programmable microphone inputs, making it perfect for settings where multiple speakers or performers are involved. This is especially useful in conference rooms, lecture halls, and places of worship, where different users may need to take turns speaking without the hassle of connecting and disconnecting microphones.

The mixer is equipped with advanced automatic mixing technology, which intelligently manages the audio levels from various microphones. This prevents feedback and minimizes background noise, resulting in clear and intelligible sound. The AT-MX351 utilizes Audio-Technica's proprietary Automatic Gain Controls (AGC) to ensure that the audio levels remain consistent, providing a professional sound experience.

In terms of connectivity, the AT-MX351 features balanced XLR inputs, allowing for secure connections that maintain audio integrity. It also includes unbalanced line inputs, catering to a wider array of equipment. The mixer offers both balanced and unbalanced outputs, providing flexibility for integration into different sound systems.

Another notable characteristic of the AT-MX351 is its user-friendly interface. The layout of the controls is intuitive, allowing operators to make quick adjustments on the fly. The clear LED indicators help users monitor signal levels easily, making it easier to identify any issues. This is particularly beneficial during live events where quick decision-making is crucial.

The AT-MX351 also incorporates a built-in limiter and compressor, which help to avoid distortion and maintain a consistent sound quality. This feature is especially important in environments with varying acoustic dynamics or when dealing with powerful audio signals.

In summary, the Audio-Technica AT-MX351 mixer stands out due to its robust features, including multiple programmable microphone inputs, advanced automatic mixing technology, and user-friendly controls. This combination of technology and usability makes it an ideal choice for audio professionals seeking reliability and high-quality sound in their applications. Whether for live performances, conferences, or installations, the AT-MX351 proves to be a reliable and effective solution in the audio mixing landscape.