Rane FVL 22 User Manual

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Professional Audio Products Data Sheet

REMOTE VCA/LIMITER

FVL 22 Remote VCA/Limiter

General Description

FVL 22

The Rane FVL 22 Remote VCA/Limiter is a stereo (2-channel) general purpose Flex building block consisting of two remotely controlled, professional recording quality VCA’s (voltagecontrolled amplifiers) along with two Limiters. Each channel operates independently or they slave together to form a locked stereo pair. The FVL 22 uses Analog Devices VCA’s for their superb noise and distortion performance.

A unique voltage calibration feature allows using a wide range of VCA control voltages. Ramp voltages may vary from standard +5VDC digital levels to +24VDC doorbell levels. Three LED indicators make calibration easy and positive.

Alternatively, the FVL 22 provides a tightly regulated +10VDC reference voltage for use with external potentiometer control. Potentiometer values may vary over a wide range of 5k to 100k ohms, using linear taper. Either type of control

Features

• TWO INDEPENDENT OR SLAVED CHANNELS

• RECORDING QUALITY VCA’s

• VOLTAGE RAMP OR POTENTIOMETER CONTROL

• UNIQUE CALIBRATION ALLOWS 5-24VDC CONTROL

• NOISE REJECTION FILTERS ON CONTROL PORTS

Parameter Specification Limit Units Conditions/Comments

Max In/Out +20 1 dB Balanced VCA Control Voltage 5-24 10% VDC Control Potentiometer Range 5k to 100k Audio or Linear Taper 20% Ohms (Linear Taper: See Rear) VCA Tracking 0 to -50: less than 0.75 dB Driving V1 & V2 Together

-50 to -80: less that 1.0 dB Driving V1 & V2 Together VCA Range 0 to -80 1 dB Maximum Attenuation VCA Control Law 0 = On; 5-24 = Off VDC Voltage Applied to V1 or V2 Control Noise Filter 3Hz, 18dB/Octave 5% Butterworth Control Hum Rejection -74 @ 50Hz; -78 @ 60Hz 2 dB Limiter Threshold Range -20 to +20 2 dBu Balanced Output Level Overall Gain 0 0.5 dB THD + Noise 0.022 0.008 % +4dBu, 20-20kHz, +20dB Threshold IM Distortion (SMPTE) 0.015 0.005 % 60Hz/7kHz, 4:1, +4dBu Signal-to-Noise Ratio 107 2 dB Balanced Out re +20dBu, 20kHz BW

91 2 dB Balanced Out re +4dBu, 20kHz BW Channel Crosstalk 90 2 dB 20-20kHz Maximum Current 500 mA RMS Current From Remote Supply

benefits from built-in AC noise filters provided on the VCA control lines. The noise filters prevent all false level changes caused by hum and noise induced on the DC control lines.

The Limiters operate over a wide balanced output range of -20dBu to +20dBu, and feature the same proven technology first made famous by Rane’s popular DC 24 Dynamic Controller. The important Auto-Slave feature first introduced in the FPL 44 is incorporated as well.

The VOLTAGE CALIBRATION and LIMITER controls are screwdriver-adjust type, with hole-plugs for additional security. Inputs and outputs are fully balanced, but operate unbalanced when required. All interconnection is done using convenient, secure and economical terminal strips. Additionally, ¼" TRS jacks provide quick single-cable interconnect to console patch points wired per the tip=send, ring=return convention. VCA control always uses the terminal strip.

• PRECISE +10VDC REFERENCE VOLTAGE

• ACCEPTS WIDE RANGE OF POTENTIOMETERS

• 40dB LIMITER RANGE

• BALANCED IN/OUT VIA TERMINAL STRIPS

• ¼" PATCH JACK FOR INSERT LOOPS

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FVL 22

Professional Audio Products Data Sheet

REMOTE VCA/LIMITER

Rear Panel Block Diagram

Applicaton Information

Use the FVL 22 anytime you need one or two channels of high quality VCA remote control of signal level. Additionally, the FVL 22 provides two channels of Limiting, practically for free.

VCA Control. The FVL 22 follows the usual convention of

zero volts turns the VCA fully on, and some maximum positive voltage turns the VCA fully off. Choose

between potentiometer, voltage ramp or switch control. The FVL 22 accepts a wide range (5k-100k) of linear taper potentiometers. A reference voltage of 10VDC is provided by the FVL 22, or you may use your own anywhere in the range of +5VDC to +24VDC. A unique,

simple calibration adjustment makes using external voltage references extremely easy. Similarly, voltage ramps with a maximum of +5VDC to +24VDC control the FVL 22 as well. Or, for simply two-state systems (e.g., On/Off, or On/-20dB, or -20/-60, or whatever), a switch closing between ground and any voltage up to +5VDC to +24VDC controls the VCAs. Note: When properly calibrated, the CAL indicator lights only for VCA fully off; all other conditions light the LOW indicator.

Limiter Section. The limiters in the FVL 22 use the same

topology as the Rane FPL 44 Quad Limiter. This is a feedback, as opposed to a feedforward, design. The control circuit

for the limiter monitors the output of the VCA, not the input of the unit. Any time the output of the VCA exceeds the threshold set on the front panel (calibrated for both balanced and unbalanced use), limiting begins. The ratio of the limiter is set automatically and is a function of the excess level the system is attempting to deliver above the preset threshold. The attack and release times of the limiter are an automatic function of the speed at which the input signal is attempting to drive the output of the unit above the threshold level.

The AUTO-SLAVE limiter function allows both channels to track, or be slaved, together. When the LIMITER switch is in the AUTO-SLAVE position, limiting occurring on either channel causes equivalent limiting in the other channel. This retains the imaging and spectral balance in stereo applications.

Using Linear Taper Controls. Audio (or log) taper pots give the best attenuation distribution around the control, but linear pots are easier to get. You can approximate an audio taper by adding a resistor to the slider per the diagram shown.

Printed in the U.S.A. on Recycled Paper

All features & specifications subject to change without notice 520-255 793