Review on SL33B Stereo Program Limiter by Rolls by Johnathan Delic

The device is simple and works well enough. The Makeup Gain control controls the input level of the compressor circuit, the Threshold control controls the compression. There is a red LED that shows the compression level. Input volume and "Makeup Boost" should be set together so that the red LED flickers slightly at the desired compression level. If it's fully on you'll hear the compression, and if it's not on at all it means there's no compression and it doesn't do anything. This means you must adjust the overall volume AFTER the rolls limiter is installed. For example, place a terminating resistor between the audio output of the TV and the input of the audio amplifier; Adjust the TV volume and Rolls "Makeup Gain" to the correct levels (so that the LED flickers on normal audio content) and set the audio power amplifier to the desired output volume. Performance was mediocre, with some noise at higher "Makeup Gain" settings, some "pumping" and other compression artifacts, although generally acceptable with the right settings. Another device you might want to consider is the "Nady DigiComp 16 - Rackmount Mono/Stereo Digital Compressor" (also by Revain), which costs less (at the time of this review), is digital rather than analog, and is more sophisticated settings, but may provide better performance.