User manual RANE FVL 22

[. . . ] Refer to the wiring diagrams on the back page of this manual. The VCA's in the FVL 22 provide maximum attenuation of the signal level when a given voltage is detected between Vl or V2 and COMMON GND. Reducing this voltage with a pot, ramp, or switch increases the audio signal level. (0 volts or open = VCA full on. ) To calibrate: set the remote pot, ramp or switch to it's maximum voltage. [. . . ] The inner ring of numbers show the angle to rotate this control for balanced operation, the outer ring for unbalanced output levels. In the INDEPENDEDENT position, each Limiter Channel operates separately. In the AUTO-SLAVE position, both Channels attenuate the same amount when either one exceeds its threshold. Indicates the power on condition of the FVL 22. REAR PANEL DESCRIPTION 1. Attach balanced input lines to the "+", "­", and SHIELD GROUND #6 terminals. To run the FVL 22 unbalanced, attach the positive lead to the "+" terminal and leave the "­" terminal open. Attach balanced output lines to the "+", "­", and SHIELD GROUND #6 terminals. To run the FVL 22 unbalanced, attach the positive lead to the "+" terminal and leave the "­" terminal open. PATCH I/O JACK provides a convenient method to use the FVL 22 as an external processor for a mixer or other device with tip = send, ring = return insert points. Use a two conductor shielded Tip-Ring-Sleeve cable. Use of the PATCH I/ O jack automatically disconnects the terminal strip input. These terminals are your gateway to the VCA control circuitry. The VREF terminal provides a precise 10VDC reference voltage output. The V1 terminal accepts a given voltage (+5 to 24VDC), which when properly calibrated, provides maximum attenuation. As this voltage decreases, the audio level increases. Decrease this voltage with whatever method suits your application (Potentiometer, switch, or voltage ramp--see back page for details). GROUND LIFT SWITCH provides the ability to separate chassis ground and signal ground. Normally, this switch should be in the LIFT position. In some circumstances it may be necessary to move it to the opposite position to eliminate stubborn hum and buzz problems. See the CHASSIS GROUNDING note below for details. CAUTION: If you are tempted to try moving this switch with your amplifier levels turned up, don't be. Always turn your amplifier levels down before changing your grounds around and then bring them up slowly. [. . . ] Try combinations of lifting grounds on units that are supplied with ground lift switches or links. If your equipment is in a rack, verify that all chassis are tied to a good earth ground, either through the line cord grounding pin or the rack screws to another grounded chassis. Units with outboard power supplies do NOT ground the chassis through the line cord. Make sure that these units are grounded either to another chassis which is earth grounded, or directly to the grounding screw on an AC outlet cover by means of a wire connected to a screw on the chassis with a star washer to guarantee proper contact. [. . . ]