The Master Module MST-S includes a versatile stereo compressor and expander dynamics section that is optimized for the use as master compressor. It offers many different possibilities for the dynamic treatment of the final stereo mix.

The master module of the master section S includes a stereo return section, the master and output amplifiers of the cue send and the main stereo master mix. The mix master chain contains some outstanding processing stages.

go to Master Main Page
go to Cue Master Page

Master Compressor

The stereo dynamics section is optimized for the application as a master compressor. It combines a versatile master compressor with a suitable expander. The Threshold control has a range from -40 to 20 dB. The Ratio control covers the range from 1:1 to infinity. Limiter operation is possible with the infinity setting of the ratio control. The release and attack times can be adjusted by independent controls in a very wide range. The range of the attack control is from 0.1 to 200 ms; the release time can be adjusted from 0.1 to 5 seconds.

In addition to the conventional setting, the compressor can produce a natural, voluminous sound that leaves the transients unchanged but offer very high loudness gain. This mode requires a very long attack time setting while the release time has to be as short as even possible. The minimum release time is determined by the low frequency distortion that is unavoidable with any regulation, because the short release time changes the gain setting of the compressor during the period time of the low frequency signal. Therefore, a general setting is not possible and a good compromise must be found for every particular mix. However, a long attack time reduces the distortion problems. The best way to tune the attack time is to start with very long values. If the attack time is too long, the compressor will simply do nothing but some sort of leveling. By decreasing the attack time, a good compromise for the particular mix must be found that leaves the transients unchanged and simulates that there is still dynamic, but begins regulation when the signal level breaks down. In addition, a rather low setting of the threshold in the range between -20 to -30 dB and a ratio in the range below 1:2 is necessary. Carefully tuning all the parameters will result in an output signal that sound like the uncompressed signal as far as dynamic impression and transient response is concerned, but it has up to 10 dB more loudness without an increase of the peak level.

The compressor has an autogain control that eliminates the need of an additional gain pot. The autogain circuit checks the positions of the compressor controls and calculates the necessary make up gain. The autogain circuit makes it easy to hear the result of a different setting very clear, as the influence of different levels does not exist. What you hear is exactly the effect of the compressor und if you change something, you will hear the effect of the new setting without the need to consider a different level, that in most cases makes more difference than the different setting of the compressor itself. The DYN switch activates the entire dynamic section.

Though an expander in the master chain is always critical, it can help to reduce the noise floor in breaks, when the compressor drives up the level and the noise as well. In addition, the expander makes recording work comfortable, since all noise in breaks can be suppressed effectively. The only control of the expander is the threshold pot with a range from -60 dB to -20 dB. The ratio is internally determined. It increases exponentially when the level drops below the threshold. A level that is only some dB below the threshold produces a small ratio while a lower level raises the ratio and therefore the gain reduction. This characteristic has been optimized for many years and results in a very effective suppression of noise while the fade down remains soft and natural. The attack time of the expander is very fast. This is one of the very important qualities of any expander and noise gate, because the best expander will not be useful if it fades in the signal too slow. The EXP switch switches on the expander.

A LED chain with 10 LED's and a range of 30 dB displays the gain reduction of the compressor. An additional 3 color LED displays the gain reduction of the expander.