Output Level Led Meter; Adjusting "Off" Attenuation - Audio Technica SmartMixer AT-MX341a Installation And Operation Manual

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 "SW16" (Figs. 3 and 4). "Zero" (0) level is
factory-calibrated at +4 dBm into 600 ohms.
Mic Phantom
SW1 SW5
Line Off
Pad
SW9
–10 dB 0 dB
–20 dB
Figure 4. Detail of internal controls.

Adjusting "Off" Attenuation

In instances when the number of microphones in use is high, it may be necessary to increase
the amount of "off " attenuation per microphone to keep the total ambient noise level low.
There are "off " attenuation adjustments inside the unit. To adjust the "off " attenuation of
channel 1, unplug the unit, remove the top cover and locate the trimpot designated on the
circuit board by "VR5" (Figs. 3 and 4). It is factory set at approximately 8 dB, the attenuation
at the middle of the control's rotation. When the control is turned fully counter-clockwise,
"off " attenuation is approximately 20 dB. Conversely, when the adjustment is turned fully
clockwise, "off " attenuation is approximately 6 dB. VR6, VR7 and VR8 control "off " attenuation
for channels 2, 3 and 4 respectively.
Mic Phantom
SW2 SW6 SW6 SW3
Line Off
Pad
SW10
–10 dB 0 dB –10 dB
VR5 VR6
–6 dB –20 dB
Mic Phantom Mic
SW7 SW4
Line Off Line
Pad
SW11 SW12
0 dB –10 dB
VR7
–6 dB –20 dB –6 dB
Rear Panel
Front Panel
Figure 3. Internal view of mixer.
Phantom
SW8
Off
Output
Pad
0 dB
VR8
–20 dB –6 dB
Line
SW15
Mic
Meter
SW16
Peak RMS
8