LX20 OPERATORS MANUAL CONTENTS SAFETY CONSIDERATIONS INSTALLATION INTRODUCTION FIRST TIME USER SYSTEM OPERATING LEVELS FRONT & REAR PANEL LAYOUT OPERATION REAR PANEL CONNECTIONS TECHNICAL SPECIFICATION LX20 CHARACTERISTICS BLOCK DIAGRAM h DRAWMER ELECTRONICS LTD.
COPYRIGHT This manual is copyrighted © 1988 by Drawmer Electronics, Ltd. With all rights reserved. Under copyright laws, this manual may not be duplicated in whole or in part without the written consent of Drawmer. UPGRADES In the interests of product development, Drawmer reserve the right to modify or improve specifications of this product at any time, without prior notice.
1 LX20 OPERATOR’S MANUAL DRAWMER LX20 Dual Expander/Compressor SAFETY CONSIDERATIONS CAUTION - MAINS FUSE TO REDUCE THE RISK OF FIRE REPLACE THE MAINS FUSE ONLY WITH THE SAME TYPE, WHICH MUST BE A CLASS 3, 230 VOLT, TIME DELAY TYPE, RATED AT 32mA WHERE THE MAINS INPUT VOLTAGE SWITCH IS SET TO 230 VOLTS AC. AND 63mA WHERE THE MAINS INPUT VOLTAGE IS 115 VOLTS AC. ALL FUSES MUST COMPLY WITH IEC127-2. THE FUSE BODY SIZE IS 20mm x 5mm.
2 LX20 OPERATOR’S MANUAL INSTALLATION The LX20 is designed for standard 19" rack mounting and occupies 1U of rack space. Avoid mounting the unit directly above power amplifiers or power supplies that radiate significant amounts of heat. Fibre or plastic washers may be used to prevent the front panel becoming marked by the mounting bolts. INTRODUCTION Many studios start as a small concern, but quickly expand into serious, productive environments.
3 LX20 OPERATOR’S MANUAL completely by either foot switch or another piece of equipment with triggering facilities, such as the M401 Midi Management System. FIRST TIME USERS First time users are well advised to take the time to familiarise themselves with the principle of compression and the various controls on the LX20. The best way of doing this is to select various pieces of pre-recorded material and try various settings, making notes of the results for the future reference.
4 LX20 OPERATOR’S MANUAL FRONT & REAR PANEL LAYOUT 1) Expand LED. This illuminates at the onset of expansion. 2) Compression indication. Moves from right to left during compression. 3) Mute LED. When on, channel is disabled except in Bypass. 4) VU indication. Measures signal level at output referred to system level. i.e. 0dB corresponds to either !10dBu or +4dBu. 5) Bypass switch. When switched to bypass, signal passes untreated. 6) Stereo Link switch. Prevents image shifting during stereo operation.
5 LX20 OPERATOR’S MANUAL OPERATION EXPAND This is the threshold control for the expander. Signals below the threshold level are attenuated, the lower the level, the greater the attenuation. The attack time is preset at 2mS and the release time is linked to the release time of the compressor. The LED above the EXPAND control indicates the onset of expansion. A switch is provided at the anticlockwise position, which disables the expander when it is not required.
6 LX20 OPERATOR’S MANUAL REAR PANEL CONNECTIONS The LX20 is equipped with jack sockets at the rear to interface with other equipment. Apart from input and output sockets, which are unbalanced, the LX20 has two important additional sockets which increase its versatility. SIDE CHAIN S/R The side chain send and return socket allows an equaliser to be inserted into the control system of the compressor, thus making the unit more sensitive to certain frequencies and less sensitive to others.
7 LX20 OPERATOR’S MANUAL TECHNICAL SPECIFICATIONS SYTEM OPERATING LEVEL !10dB OR +4dB, selected by internal switches INPUT IMPEDANCE 47 Kohms unbalanced OUTPUT Unbalanced NOISE @ unity gain !85dB (22Hz to 22KHz) MAX GAIN 40dB DISTORTION @ unity gain Less than 0.3% DISTORTION @ 10dB compression Less than 0.
8 LX20 OPERATOR’S MANUAL LX20 CHARACTERISTICS
9 LX20 OPERATOR’S MANUAL BLOCK DIAGRAM
