9
The compression slope does not change the threshold attack level or the threshold indication. The release
time will determine how long the function will hold.
Control Settings:
Increase the input level control until the Vu meter begins to indicate compression. The
threshold attack LED indicator will be illuminated continuously since the average signal level will now be
above threshold. The amount of additional compression is dependent upon the input level control setting.
When the release control is set for the shortest release time, maximum average level will be obtained
with an increase in audio level and distortion. Longer release time will provide the smoothest action with
minimum audio level changes, minimum distortion and average level slightly lower than the maximum.
Adjust the output level control to obtain the level required.
Typical Application
: This mode is used whenever a small or intermediate amount of compression is
desired.
Compression Only
When the average level of the input signal to the compressor/limiter is continually above the threshold
attack level, this mode occurs.
Control Settings
: Increase input level until the LED gain reduction meter indicates compression.
Generally, longer release times should be used.
Typical Application
: Wherever a large amount of compression is required, operate in this mode.
Limiting and Compression with Additional Output Limiting/Broadcast Application
This mode is the same as the previous “Compression and Limiting Simultaneously” mode, except that
additional amplitude protection at a fixed level is provided by driving the output amplifier to maximum
output, (peak clipping).
The system provides “limiting-on-limiting,” which assures maximum power output or maximum percent
modulation. When utilized in this manner, an external pad after the Model V 610 is needed to reduce the
higher output level to line level.
The red overload lamp indicator is set to illuminate for output amplifier signals of approxi22
dBu, well in advance of the actual output amplifier limiting of +18 dBu or greater. Under normal
circumstances, this is the preferred operation. However, additional precise laboratory lamp indication at
the point of output amplifier limiting may be preferred. Calibration of the overload light for this function
is available at a nominal charge from the factory.
Control Settings
: Set the controls in the same manner as described in the previous “Compression and
Limiting Simultaneously” mode except that the output level control should be set so the red overload
lamp begins to flash. Thus, a final fixed amplitude protection line is provided to prevent subsequent
overload distortion, over-modulation, etc.
Typical Applications
: This mode is particularly applicable to broadcast applications where a maximum
percentage of modulation is required. A resistance in series, (e.g. 600 ohms, 1000 ohms potentiometer,
etc.) where signal output is sufficient to pad the signal positive down to st8 dBm broadcast line