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Radio Design Labs RDL ST-CL2 Compressor/Limiter Line Level Audio Output Average

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Radio Design Labs RDL ST-CL2 Compressor/Limiter Line Level Audio Output Average
Grade B condition. Comes as pictured.


The ST-CL2 is a high performance compressor/limiter designed to maintain a constant average output level and effective peak control over a wide range of input levels. The input and output are line level and each may be wired balanced or unbalanced. Trimmers provide adjustment for all usual professional and consumer audio input and output levels. Internal detectors feed three timing circuits. The threshold level and slope of each timing circuit are incremented to respond sequentially to signals of varying amplitude and energy levels. The ST-CL2 features a soft-knee compression threshold and compression ratio which automatically adjust to the program material. Two LED indicators cover the incremental ranges of compression, making setting of the input level quick and easy. Two ST-CL2s may be strapped together for stereo operation by connecting the coupling terminals between the two modules.


10 kΩ Balanced (may be connected unbalanced)

Input Signal Range:
-10 to +4 dBu, adjustable (for 6 dB gain reduction); +22 dBu maximum

150 Ω Balanced (may be connected unbalanced)

Output Signal Range:
OFF to +8 dBu, adjustable

Frequency Response:
10 Hz to 20 kHz (± 0.2 dB) over full compression range

Noise below +4 dBu output:
< -78 dB (unweighted; +4 dBu input/output)

Total Harmonic Distortion:
< 0.05% @ 1 kHz below compression threshold;
< 0.1% @ 1 kHz with 3 dB gain reduction;
< 0.15% @ 1 kHz with 6 dB gain reduction

> 60 dB (50 to 120 Hz)

Attack Time:
Averaging Compressor: 500 ms (+4 dBu input);
Fast Compression: <10 ms (+20 dBu input);
Peak Limiting: Instantaneous

Release Time:
Automatically adjusting up to 500 ms

Compression Ratio:
Automatically adjusting 1.5:1 to 10: 1

Peak Limiter:

Stereo COUPLE interconnection provided

Indicators (2):
Yellow LED for NORMAL Compression,
Red LED for HEAVY Compression

Ambient Operating Environment:
0° C to 55° C

Power Requirement:
24 Vdc @ 50 mA, SupplyFlex