1. Functionality (cont’d.)
1-7. Monitor channel A & B independent Gain Control
The signal levels of the AM4 were originally designed with unity gain between any input
and any output. The signal levels for channel A & B can be increased or decreased up to
+30/–20 dB in 1 dB increments.
Increase or decrease gain
To increase / decrease gain, use combination of front panel control button [ A ] or [ B ], and
[ INPUT ] or [ SDI ] buttons. Button [ A ] or [ B ] selects the intended channel to change.
The [ INPUT ] button increases the gain and the [ SDI ] button decreases the gain.
For instance, to increase the gain of channel A, press and hold the [ A ] button, then press
[INPUT ] until the desired signal level is reached.
[ A ] or [ B ] to select channel …. A or B
[ INPUT ] gain increase. …… UP
[ SDI ] gain decrease. ……… DOWN
Gain display
Internal gains can be displayed on the VU meters. To see the current gain, press and hold
the [ A ] or [ B ] button for approximately a one-half second. The left channel VU meter
shows the amount of gain applied, relative to the right channel meter. The right channel
meter indicates the relative reference for unity gain. Each LED bar is equivalent to 1 dB.
(The reference level shown on the right channel VU is always at –30 dBFS. This –30 dBFS
reference was chosen for convenience only, in order to accommodate and display the gain
range of –20 to +30 dB.)
For instance when channel B’s gain is increased by +20 dB, the left channel gain display
shows the bar at –10 dBFS ( -30 + 20 = -10 ). The right channel’s VU bar is always at the
relative unity gain reference level, placed at -30 dBFS.
The factory default gain is 0 dB.