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Control settings:
For low signal levels (e.g. Microphone, etc.), no attenuation of the input signal is
required and the threshold attack LED will occasionally flash whenever input levels are above threshold.
For higher signal levels (e.g. Line, etc.), it is preferable to operate above the point of threshold and thus
maximize the signal-to-noise ratio of the system. The slope control is set to approximately normal linear
amplification (“100” slope control setting = fully clockwise), the release control setting is not critical and
may be set at maximum time. The input level control is adjusted so the threshold attack LED is
continually illuminated. For either of these two conditions, adjust the output level control to obtain the
level required.
Typical Application:
This mode provides amplification for input signal levels below the -40 dBu
threshold attack level, such as when normal microphone output levels, (-50dBu), are terminated directly
to the Model V610. For higher level input signals, setting the slope control to approximately normal linear
amplification has the practical equivalent of switching the Model V610 out of the circuit.
Peak Limiting Only
For all levels of the input signal waveform where peak signals are above threshold, and average
level is below threshold, peak limiting occurs.
Peak waveforms or transients, by definition, are high amplitude, short time-base, and are beyond the
audible range, (20 kHz). Thus, the independent limiting function will attack, instantaneously, to provide
complete peak overload protection. The limiting curve approximately follows the compression curve and,
a continuously variable limiting curve is obtainable. For positive amplitude protection, a flat compression
slope provides a flat limiting protection line.
Control Settings:
Increase the input level control until the threshold attack LED occasionally begins to
flash, indicating peaks are beginning to cross threshold. The control setting will approximately represent
the maximum amplitude of the peak material for this audio program selection. The maximum amount of
peak limiting will occur just prior to the point where the VU meter begins to indicate gain reduction. The
slope control is set for minimum, (flat), slope of the limiting, (and compression), curve (fully clockwise).
Since compression is not being activated, the release control setting is not critical and would be set for
maximum release time, (fully clockwise). Adjust the output level control to obtain the level required.
Typical Application:
Maximum Vu output without affecting dynamic range is obtained with maximum
peak limiting. With no compression of audio program source material, no peak program material will be
transferred through the Model V610, thus allowing improved audio level. As a result, increased
headroom will be realized without associated “peak overload”, (typically 10dB). In addition, an
improvement in signal to noise ratio will be achieved in proportion to the increase in signal level.
Compression and Limiting Simultaneously
This mode of operation occurs when the average level continually alternates above and below the
constant threshold attack level.
When the audio program waveform initially crosses threshold, the limiter will attack and hold until the
compression function takes over. The cycle will repeat each time the average level crosses the threshold.