Great River PWM-501

Description

Output level control This control sets the amount of make-up gain in the output amplifier. Use it to adjust the output signal level. Threshold control This control determines the portion of the signal that the rest of the sidechain will use to control the operation of the PWM-501. At low levels (0-50) the unit looks at all or most of the signal and acts as a compressor, at higher levels (50-100) it looks at peaks and the unit functions more as a limiter. The signal the threshold circuit is fed comes from the Feedforward/feedback control. Ratio control This control sets the percentage of the control signal sent to the PWM attenuator. Fully counterclockwise divides the signal the most, giving the lowest ratio. The actual ratio is approximate, as it is dependent on the variables of the threshold, attack and release times, as well as the setting of the feedforward/feedback control. Attack time control This control sets the initial charging speed of the time constant capacitor. The circuit feeding this capacitor is an absolute value peak detector, so it can be very fast. It can also generate unpleasant distortion if it is too fast for the signal content. Faster attack times are in the counterclockwise direction of the control. Link switch This switch will link the control voltage between PWM-501 units installed in a rack with the correct interconnections on the backplane bus. Any PWM-501's connected via the link system will "or" their control voltages. One unit can be used to control all, or each can contribute. To defeat a units' contribution to the bus, turn the local Threshold and Attack all of the way up, and the Ratio all the way down. This control voltage is unique to the PWM-501 and is not compatible with other manufacturers systems, so the bus must be broken up if other units are using it in the same rack. The bus used is Pin 6 of the backplane connector.