User manual ROLLS CL151

[. . . ] For example, you may wish to automatically lower a music signal under a paging microphone signal, then have the music return to normal level after the page is over. This would be accomplished by running the music into the compressor, and having the page signal connect into the Side Chain return. The page signal must also be connected to the main mixer or amplifier as well. [. . . ] Set the gate THRESH for "off", the COMP RATIO for 1:1, and the compressor THRESH for +10. These initial settings essentially bypass the gate and compressor circuits. The compressor RATIO and THRESH controls work together to control the amount of compression, and the point at which compression begins respectively. Decreasing the THRESH control lowers the amount of signal required to begin compression - so it compresses sooner. This works with the RATIO control which, when increased, increases the amount of compression. The gate THRESH control, after being turned slightly counterclockwise from the "off" position, goes to its maximum level. This means it requires a higher signal level to "open" the gate. As the gate THRESH control is turned counterclockwise, a lower and lower signal is required to open the gate. The gate REL (release time) control sets the amount of time taken for the gate to "close" after the signal drops below the THRESH level. For example, the CL151 will continue passing a sustaining note until the level drops below the THRESH level, and the REL time has passed. FRONT PANEL INPUT: Adjusts the amount of input signal to the CL151, from no signal to +20 dB. GATE REL: This control adjusts the amount of time taken for the gate circuitry to "close" or mute the output, after the signal level has dropped below the gate Threshold level. THRESH: Sets the point at which the input signal must surpass to "open" the gate circuitry or allow signal to pass to the output. GATE LED: When lit, indicates that the gate is "closed" or the output is muted. COMP RATIO: This control sets the signal to compression ratio. This ratio relates to the amount of increase of input compared to output signal. Thus, at a 1:1 ratio, a 1 dB increase of input signal will result in a 1 dB increase of output signal. At 2:1, a 2 dB increase of input signal will result in only 1 dB increase of output signal. At 8:1, an 8 dB increase of input signal will result in a 1dB increase of output signal. [. . . ] SIDE PANEL PHANTOM POWER: Jumper header for connecting 12 VDC phantom power to the XLR Mic Input. Phantom power is engaged by carefully removing the jumper, and reconnecting it to the pins toward the CL151 controls. Connection Example USING THE SIDE CHAIN To access the compressor detector circuit directly, Rolls has included a Side Chain jack. The Side Chain works somewhat like an effects loop, with a send and return point. [. . . ]