PLA DL210NET Digi-Loop™ DSP Induction Loop Amplifier
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6d. AGC
Automatic Gain Control measures the average level of the signal and applies gain reactively to keep the output level constant. It
also limits the output power and reduces or eliminates distortion due to clipping that would normally occur without AGC.
6d1-6. AGC Level, Hold Time, Attack, Release
Preset
provides default settings for Voice and Music, and only the Amount is adjustable. A Custom preset allows adjustment
of the Hold Time, Attack, and Release. Voice is designed for pauses in the audio, where Music is designed for more
constant-level sources.
Amount
of the AGC can be adjusted to a maximum of 20dB of around the calibrated level, or “target” level. For people
familiar with traditional AGC, the Target is internally set to the calibrated level and is not adjustable, and the Minimum Level
(also called “Threshold”) is internally set relative to the calibration target level and is not adjustable. The calibrated “target”
level is set in Tech Tools-Calibrate, and this is the level the AGC will attempt to hold.
Hold Time
is how long the gain is maintained on signal when the automatic gain settings take effect. In the Custom preset,
the Hold Time is adjustable from 1 second to 60 seconds in 1 second steps.
Attack
is the speed at which the AGC reacts when the level of the input signal crosses the threshold. Short settings react to
the signal quickly, while long attack times have a lagging effect. In the Custom preset, the Attack time is adjustable from 0.5 s
to 3.5 s in 0.5 s steps.
Release
is the amount of time that the AGC continues to work after the input signal drops beneath the threshold. Short
settings release the signal quickly, while long release times have the effect of sustaining the signal. In the Custom preset, the
Release time is adjustable from 0.5 s to 3.5 s in 0.5 s steps.
