Aphex 1788A Premium Eight Chan Mic Pre - Manual (Page 15)

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MICROPHONE PREAMPLIFIER
Page 15
Instruction Manual
4. FUNCTIONS IN DETAIL
4. FUNCTIONS in DETAIL
4.1 LOCAL BLOCK
Channel Select and Channel Status Readout
Select LOCAL CONTROL and use the CHANNEL SELECT buttons to choose one of eight
channels. Only one channel can be selected at a time, unless the MULTIPLE SELECT
button is engaged, making it possible to create a group of channels.
Each channel has its own Channel Status Readout. At the top is a two-digit gain
readout LED displaying the input or output gain setting depending on the status of the
GAIN SELECT button. The vertical 12 segment LED meter on the right side indicates
the available peak headroom measured in dB (4dB increments). To indicate that Local
Block functions (Polarity Reverse, Low Cut 75Hz, 26dB PAD, Phantom +48V and Enable
Limiter) have been engaged, the associated LED in the individual channel status readouts
is illuminated. When MUTE is engaged, the two-digit GAIN display at the top of the
individual channel status readout will flash double dash marks to indicate their muted
status. The flashing dash marks will alternate with the current gain setting. Even though
both analog outputs are muted, the digital outputs will not be muted. All indicators and
metering can be monitored at the remote location.
Gain Select
The GAIN SELECT button determines the function of the ADJUST control and the status
of the gain display in the individual channel status readout. The gain LED readout reflects
either the input or output setting depending on the position of the GAIN SELECT button.
Continually depressing the button will cycle through the three modes: Input, Main
Output and Aux Output. When Input is selected, ADJUST controls the input gain. When
Output (Main or Aux) is selected, the ADJUST controls the maximum output level.
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Input Gain Control
The input gain is the actual gain of the front-end preamp section, before the variable Main
or Aux output settings take effect. Use Input Gain to bring the microphone’s signal level up
to the appropriate range as indicated on the channel’s Headroom Meter. The available
range of control is from +26dB to +65dB in 1dB stops (not “steps”) with individual
precision within +/- 0.08dB.